westwood primary school structural specification stage 4 · pdf filewestwood primary school...

Westwood Primary School Structural Specification

Stage 4

17 August 2017

Table of Contents

Title Page

D Groundwork 3

D20 Excavating and filling 5

E In situ concrete/Large precast concrete 13

E05 In situ concrete construction generally 15

E10 Mixing/casting/curing in situ concrete 18

E20 Formwork for in situ concrete 24

E30 Reinforcement for in situ concrete 27

E40 Designed joints in in situ concrete 30

E41 Worked finishes to in situ concrete 32

E60 Precast/ composite concrete floors/ roof decks 34

F Masonry 35

F10 Brick/ block walling 37

F30 Accessories/ sundry items for brick/ block/ stone walling 43

G Structural/Carcassing metal/timber 48

G10 Structural steel framing 50

D

Groundwork

D20

Excavating and filling

Westwood Primary School Civil & Structural Specification

D20 Excavating and filling

To be read with Preliminaries/General conditions

GENERALLY/THE SITE

110 SITE INVESTIGATION • Report: Applied Geology - Report on Ground Investigation at Westwood Primary School, March - Report No. AG2639-17-AB91 - May 2017 and Applied Geology - Soakaway Testing Memo Report No AG2639-17-AC11 - Issue 2 - June 2017.

145 VARIATIONS IN GROUND WATER LEVEL • Give notice: If levels encountered are significantly different from levels in the site investigation report or previously measured.

150A EXISTING SERVICES, FEATURES AND STRUCTURES • Services: Refer to M&E design information, STATS drawings and Survey Solutions Utilities and CCTV Drainage Investigation Drawing 19450UG-01. • Site features to be retained: Refer to Landscape Architects and M&E Engineers details. • Structures: An existing live school is currently located on the site.

The existing Westwood Primary School is located off Maple Grove in March PE15 8JT. The site is circa 2.6ha in area and is relatively flat. There is a change in level of circa 0.6m from the highest point, located towards the north east to the lowest towards the south west. The site is bound by Maple Grove to the north, Henson Road to the east and private housing and gardens to the remaining boundaries. The site consists of an existing school which is located towards the north west of the site, with hard surfaced playgrounds towards the north west boundary. A car park is located towards the middle of the north boundary and is accessed directly off Maple Grove. Playing fields are located towards the south and east of the site. The school building was extended in 2003 to provide two additional classrooms and an associated corridor. The extension was located to the south of the building adjacent the playing fields.

The proposed scheme consists of a series of extensions and infills to the existing school, with internal alterations and modifications to the external landscaping. The new extension towards the south of the existing building will predominantly contain new classrooms, along with a breakout space and associated circulation, toilet facilities and storage. The new extension adjacent the existing main entrance, to the north of the school, is to house a general office and a new entrance lobby. A new enclosed link corridor is to be provided between the new PPA room and new classroom extension. A small extension adjacent the existing kitchen will provide new circulation space between the main hall and the servery. The existing open internal courtyard towards the south west of the building will be infilled to form a new group room. Minor modifications are planned to the inside of the building, however they are predominantly none structural and reference should be made to the Architectural section for more detail.

240 ADJACENT EXCAVATIONS • Requirement: Where an excavation encroaches below a line drawn at an angle from the nearest formation level of another higher excavation, the lower excavation, all work within it and backfilling thereto, must be completed before the higher excavation is made. • Angle of line below horizontal: 45°. • Backfill material: Compacted general filling as clause 626.

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242 EXCAVATIONS ADJACENT TO EXISTING BACKFILLED TRENCHES • Proximity: When width of undisturbed ground between the two excavations will be less than the depth of the shallowest excavation. • Action: Assume that the ground between the trenches is unstable and provide side support accordingly.

244 EXCAVATIONS ADJACENT TO EXISTING FOUNDATIONS • Prior to commencing excavation: - Excavate trial pits adjacent to existing foundations to determine extent and formation levels. - Allow for inspection of trial pits. - Allow time for amendment of details if required. Time period: 5 working days . • Backfill material to new excavation: As clause 626 .

248 BACKFILL TO EXCAVATIONS LOWER THAN FOUNDATION FORMATION LEVEL • Critical level: - Distance between near faces of foundation and lower excavation less than 1 m: 150 mm above foundation formation level. - Otherwise: 150 mm above level at which line defined in clause 240 cuts near face of lower excavation. • Backfill material: - Below critical level: Lean mix concrete. - Above critical level: Compacted general filling as clause 626.

250 PERMISSIBLE DEVIATIONS FROM FORMATION LEVELS • Beneath mass concrete foundations: ±25 mm. • Beneath ground bearing slabs and r.c. foundations: ±15 mm. • Embankments and cuttings: ±50 mm. • Ground abutting external walls: ±50 mm, but such as to ensure that finished level is not less than 150 mm below dpc.

255 ACCURACY - LINEAR DIMENSIONS • Permissible deviations from linear dimensions generally: As CIRIA Special publication C709 .

260 INSPECTING FORMATIONS • Give notice: Make advance arrangements for inspection of formations for foundations and filling formations. - Notice (minimum): 5 days. • Preparation: Just before inspection remove the last 150 mm of excavation. • Trim to required profiles and levels. - Loose material: Remove. • Seal: Within 4 hours of inspection, seal formations with blinding concrete.

270 FOUNDATIONS GENERALLY • Give notice if: - A natural bearing formation of undisturbed subsoil is not obtained at the depth shown on the drawings. The formation contains soft or hard spots or highly variable material.

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275 FOUNDATION BEARING • Requirement: Foundations are designed to bear on: - Strata: March Gravels Member. - Safe bearing capacity (minimum): 150 kN/m². • Give notice: If the material at the design depth of the foundation does not comply with this description, or contains soft or hard spots or highly variable material.

285 STEPS IN FOUNDATION FORMATIONS • Depth of formation below ground level (minimum): - Existing ground level: Not applicable. - Finished ground level: Not applicable. • Step dimensions: - Distance between steps (minimum): 600. - Height of step (maximum): 300. Length of overlap (minimum): 2 times height of step.

310 UNSTABLE GROUND • Generally: Ensure that the excavation remains stable at all times. • Give notice: Without delay if any newly excavated faces are too unstable to allow earthwork support to be inserted. • Take action: If instability is likely to affect adjacent structures or roadways, take appropriate emergency action.

320 RECORDED FEATURES • Recorded foundations, beds, drains, manholes, etc: Treat as clause 335. • Contaminated earth: Remove and disinfect as required by local authority.

330 UNRECORDED FEATURES • Give notice: If unrecorded foundations, beds, voids, basements, filling, tanks, pipes, cables, drains, manholes, watercourses, ditches, etc. not shown on the drawings are encountered.

335 NEW FOUNDATIONS CROSSING OLD FOUNDATIONS OR WALLS • Break out: The old foundation/ wall where it crosses the new foundation/ wall: - Length of breaking out: Width of the new foundation/ wall plus 500mm. - Depth of breaking out: Full depth of existing foundation/ wall. • Disturbed/ softened soil: When the formation for the old foundation/ wall is deeper than the formation of the new foundation. - Excavate: Soil that has been disturbed and/ or softened on either side of the old wall/ foundation, and for 750 mm into undisturbed ground on either side. • Step up: The formation for the new foundation as necessary on either side of the old foundation/ wall until the formation is at its design level. - Size of steps: As clause D20 285. • Backfilling beneath design formation level: Fill with concrete as foundation is cast.

337 OLD FOUNDATIONS OR WALLS BENEATH NEW GROUND SUPPORTED SLAB • Break out: The old foundation/ wall to a depth below the slab formation level of at least 500 mm. - Excavate: Soil that has softened on either side of the old wall/ foundation. • Backfill: Obtain instructions if depth of fill will be greater than 600 mm, otherwise backfill with compacted hardcore.

350 EXISTING WATERCOURSES • Diverted watercourses which are to be filled: Before filling, remove vegetable growths and soft deposits.

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360 EXCESS EXCAVATION • Excavation taken wider than required: - Backfill: With hardcore as clause 626. • Excavation taken deeper than required: - Backfill: Under foundations: Concrete grade as E10.

370 UNDERGROUND STRUCTURES IN LANDSCAPE AREAS • Generally: Remove walls, roads, foundations, disused services, drains, manholes and the like to minimum depth. • Minimum depth below finished levels: - Grass, ground cover and perennial planting: 500 mm. - Shrub planting: 750 mm. - Within 2 m of tree planting: 1000 mm. • Walls and slabs remaining: In every 10 m² of wall or slab, make a drainage hole at least 600 mm diameter.

DISPOSAL OF MATERIALS

410 EXCAVATED TOPSOIL STORAGE • Storage: Stockpile in temporary storage heaps as indicated on Landscape Architects drawings .

450 WATER • Generally: Keep all excavations free from water until: - Formations are covered. - Below ground constructions are completed. - Basement structures and retaining walls are able to resist leakage, water pressure and flotation. • Drainage: Form surfaces of excavations and fill to provide adequate falls. • Removal of water: Provide temporary drains, sumps and pumping as necessary. Do not pollute watercourses with silt laden water.

454A GROUND WATER LEVEL, SPRING OR RUNNING WATER • Give notice: If the water levels differ on site to those identified in the site investigation report. Some foundations may be below the recorded water strike levels and as such dewatering may be required. • Springs/ Running water: Give notice immediately if encountered.

457 PUMPING • General: Do not disturb excavated faces or stability of adjacent ground or structures. • Pumped water: Discharge without flooding the site or adjoining property. • Sumps: Construct clear of excavations. Fill on completion. - Locations: Contractor's choice .

460 PERMANENT DRAINAGE SYSTEM • Disposal of water from the excavations through system: Not permitted.

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FILLING

500 PROPOSED FILL MATERIALS • Details: Submit full details of proposed fill materials to demonstrate compliance with specification, including: - Type and source of imported fill. - Proposals for processing and reuse of material excavated on site. - Test reports as required elsewhere. • Timing: At least 21 days before starting filling.

510 HAZARDOUS, AGGRESSIVE OR UNSTABLE MATERIALS • General: Do not use fill materials which would, either in themselves or in combination with other materials or ground water, give rise to a health hazard, damage to building structures or instability in the filling, including material that is: - Frozen or containing ice. - Organic. - Contaminated or noxious. - Susceptible to spontaneous combustion. - Likely to erode or decay and cause voids. - With excessive moisture content, slurry, mud or from marshes or bogs. - Clay of liquid limit exceeding 80 and/or plasticity index exceeding 55. - Unacceptable, class U2 as defined in the Highways Agency 'Specification for highway works', clause 601.

512 LIMITATION OF SULFATE CONTENT IN FILL MATERIALS • Test specification: To BS 1377-3. • Sulfate content: Expressed as SO4. - Water soluble sulfate (maximum): 1500 mg/L in 2:1 water/ soil extract. - Total potential sulfate (maximum): 0.6%. - Oxidizable sulfides (maximum): No requirement. • Certificates of test result: Submit.

520 FROST SUSCEPTIBILITY • General: Except as allowed below, fill must be non frost-susceptible as defined in Highways Agency 'Specification for Highway Works', clause 801.8. • Test reports: If the following fill materials are proposed, submit a laboratory report confirming they are non frost- susceptible: - Fine grained soil with a plasticity index less than 20%. - Coarse grained soil or crushed granite with more than 10% retained on a 0.063 mm sieve. - Crushed chalk. - Crushed limestone fill with average saturation moisture content in excess of 3%. - Burnt colliery shale. • Frost-susceptible fill: May only be used: - At depths below the finished ground surface greater than: 600 mm. - Within the external walls of buildings below spaces that will be heated. Protect from frost during construction. - Where frost heave will not affect structural elements.

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525 TESTING OF SUITABILITY OF FILL MATERIALS BEFORE START OF FILLING • Laboratory: UKAS/ NAMAS accredited laboratory. • Submit report to: Structural engineer (two copies). - Timing: 21 days before starting filling. • Samples: Deliver to laboratory as required. - Additional requirements: None. • Tests: As directed. • Frequency: Submit with tender proposed rate and frequency of testing to demonstrate continuing compliance of imported or reprocessed fill with specified properties.

530 PLACING FILL • Surfaces of excavations and areas to be filled: Free from loose soil, topsoil, organic material, rubbish and standing water. • Freezing conditions: Do not place fill on frozen surfaces. Remove material affected by frost. Replace and recompact if not damaged after thawing. • Adjacent structures, membranes and buried services: - Do not overload, destabilise or damage. - Submit proposals for temporary support necessary to ensure stability during filling. - Allow 14 days (minimum) before backfilling against in situ concrete structures. • Layers: Place so that only one type of material occurs in each layer. • Earthmoving equipment: Vary route to avoid rutting.

535 COMPACTION GENERALLY • General: Compact fill not specified to be left loose as soon as possible after placing. • After compaction: Surface of each layer must be well closed, showing no movement under compaction plant, and without cracks, holes, ridges, loose material and the like. • Defective areas: Remove and recompact to full thickness of layer using new material.

540 BENCHING IN FILL • Adjacent areas: If, during filling the difference in level between adjacent areas of filling exceeds 600 mm, cut into edge of higher filling to form benches 600 mm minimum width and height equivalent to depth of a layer of compacted filling. • New filling: Spread and compact to ensure maximum continuity with previous filling.

610 COMPACTED FILLING FOR LANDSCAPE AREAS • Fill: Material capable of compaction by light earthmoving plant. • Filling: Layers not more than 200 mm thick. Lightly compact each layer to produce a stable soil structure.

615 LOOSE TIP FILLING FOR LANDSCAPE AREAS • Filling: Do not firm, consolidate or compact when laying. Tip and grade to approximate levels in one operation with minimum of trafficking by plant.

617 HIGHWAYS AGENCY TYPE 1 UNBOUND MIXTURE • Fill: To Highways Agency 'Specification for highway works', clauses 801 and 803: - Crushed rock (other than argillaceous rock). - Crushed concrete. - Recycled aggregates. - Crushed non-expansive slag. - Well-burned non-plastic colliery shale. • Amendments to requirements in Highways Agency 'Specification for highway works': None. • Filling: To Highways Agency 'Specification for highway works', clause 802.

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618 HIGHWAYS AGENCY TYPE 2 UNBOUND MIXTURE • Fill: To Highways Agency 'Specification for highway works', clauses 801 and 804: - Crushed rock (other than argillaceous rock). - Crushed concrete. - Crushed non-expansive slag. - Well-burned non-plastic colliery shale. - Natural gravel. - Natural sand. • Amendments to requirements in Highways Agency 'Specification for highway works': None. • Filling: To Highways Agency 'Specification for highway works', clause 802.

620 SUBGRADE IMPROVEMENT LAYER (CAPPING) • Fill: To Highways Agency 'Specification for highway works', Table 6/1, Class 6F1 or 6F2. • Filling: Place and compact to Highways Agency Specification for highway works, Table 6/1, clause 612 and clause 613.3, 613.9 and 613.10.

626 COMPACTED GENERAL FILL • Suitable material: 6F1 or 6F2 in accordance with Clause 620. • Excavated material: Select suitable material and keep separate. • Filling: Spread and level material in layers. As soon as possible thoroughly compact each layer. • Required compaction: As Clause 620. • Proposals: Well in advance of starting work submit details of proposed: - Materials to be used, including quantities of each type. - Type of plant. - Maximum depth of each compacted layer. - Minimum number of passes per layer.

640 STARTER LAYER OF COMPACTED FILLING • Fill: Suitable hard granular material. Compact thoroughly. • Thickness: 450 mm .

650 PROTECTION OF COMPACTED FILLING • Temporary protective filling: Before allowing construction traffic, raise level of compacted cohesive soil filling at least 150 mm above formation level using properly compacted temporary filling. • Removal: Remove temporary protective filling from site before permanent construction.

700 BACKFILLING AROUND FOUNDATIONS • Under oversite concrete and pavings: Hardcore as clause 710. • Under grassed or soil areas: Material excavated from the trench, laid and compacted in 300 mm maximum layers.

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710 HARDCORE FILLING • Fill: Granular material, free from excessive dust, well graded, all pieces less than 75 mm in any direction, minimum 10% fines value of 50 kN when tested in a soaked condition to BS 812-111, and in any one layer only one of the following: - Crushed rock (other than argillaceous rock) or quarry waste with not more binding material than is required to help hold the stone together. - Crushed concrete, crushed brick or tile, free from plaster, timber and metal. - Crushed non-expansive slag. - Gravel or hoggin with not more clay content than is required to bind the material together, and with no large lumps of clay. - Well-burned non-plastic colliery shale. - Natural gravel. - Natural sand. • Filling: Spread and level in 150 mm maximum layers. Thoroughly compact each layer.

730 BLINDING • Surfaces to receive sheet overlays or concrete: Blind with: - Concrete where shown on drawings; or - Sand, fine gravel, or other approved fine material applied to fill interstices. Moisten as necessary before final rolling to provide a flat, closed, smooth surface. • Sand for blinding: To BS EN 12620, grade 0/4 or 0/2 (MP). • Permissible deviations on surface level: +0 -25 mm.

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E

In situ concrete/Large precast concrete

E05

In situ concrete construction generally


E05 In situ concrete construction generally

To be read with Preliminaries/General conditions.

220 STRUCTURAL DESIGN PROVIDED • Description: Pad foundations, trench fill footings, ground slabs and below ground drainage as per drawings. • Requirements: - Generally: As section B50. - Additional requirements: None. • Production/ execution records: In accordance with the designated code of practise.

223 STRUCTURAL DRAWINGS AND SCHEDULES • Standards: - Drawings: To 'Standard method of detailing structural concrete' published by the Institution of Structural Engineers. Reinforcement schedules: To BS 8666.

225 TEMPERATURE RECORDS • Requirement: Throughout period of concrete construction record: - Daily: Maximum and minimum atmospheric shade temperatures. - Under adverse temperature conditions: Temperature at commencement and end of placing. • Equipment: Contractor's choice . - Location: In the shade, close to the structure.

235 OPENINGS, INSERTS AND FIXINGS • Requirement: Collate all information. • Submit: Details where openings, inserts and fixings can only be accommodated by adjustments to reinforcement. • Locate reinforcement: To ensure specified minimum cover at openings and inserts and to be clear of fixing positions.

290 ACCURACY OF CONSTRUCTION • Setting out: To BS 5964-1. • Geometrical tolerances: To Section 7 of the 'National Structural Concrete Specification for Building Construction'. - Conflicts: Notwithstanding tolerances specified elsewhere, do not exceed requirements for compliance with the designated code of practice. - Substitution of alternative requirements: None.

300 LEVELS OF STRUCTURAL CONCRETE FLOORS • Tolerances (maximum): - Level of floor: ±10 mm as measured from nearest temporary bench mark. Steps in floor level: ±5 mm.

310 SURFACE REGULARITY OF CONCRETE FLOORS TO BS 8204 - GENERAL • Standard: To BS 8204-1 or -2. • Measurement: From underside of a 2 m straightedge (between points of contact) placed anywhere on surface and using a slip gauge.

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315 SURFACE REGULARITY OF CONCRETE FLOORS TO BS 8204 - TOLERANCE CLASS S R2 • Location: Lower Ground Floor Slab. • Abrupt changes: Not permitted.

410 IN SITU CONCRETE CONSTRUCTION - SUPERVISION/ CHECKING • Standard: To BS EN 13670, Execution Class 2.

430 SURFACE CRACKING All • Method of measurement: graduated magnifying devices. • Critical crack width: 0.3 mm . • Action: Should cracks occur that are wider than the critical crack width: - Survey: Frequency and extent of such cracks and investigate cause. Report: Findings together with recommendations for rectification.

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E10

Mixing/casting/curing in situ concrete


E10 Mixing/casting/curing in situ concrete


CONCRETE

101 SPECIFICATION • Concrete generally: To BS 8500-2. • Exchange of information: Provide concrete producer with information required by BS 8500- 1, clauses 4 and 5.

105 DESIGNATED CONCRETEConmcrete to trench fill footings and pads • Designation: FND2. • Fibres: Not required. • Aggregates: - Size (maximum): 20 mm. - Coarse recycled aggregates: Permitted, but with additional requirements for RA as clause 310. - Additional aggregate requirements: None. • Special requirements for cement/ combinations: None. • Consistence class: Submit proposals. • Chloride class: Cl 0.40. • Admixtures: Concrete producer's choice. • Additional mix requirements: None.

105A DESIGNATED CONCRETEBlinding • Designation: GEN1. • Fibres: Not required. • Aggregates: - Size (maximum): 20 mm. - Coarse recycled aggregates: Permitted, but with additional requirements for RA as clause 310. - Additional aggregate requirements: None. • Special requirements for cement/ combinations: None. • Consistence class: Contractor's choice. • Chloride class: Cl 0.40. • Admixtures: Concrete producer's choice. • Additional mix requirements: None.

MATERIALS, BATCHING AND MIXING

215 READY-MIXED CONCRETE • Production plant: Currently certified by a body accredited by UKAS to BS EN 45011 for product conformity certification of ready-mixed concrete . • Source of ready-mixed concrete: Obtain from one source if possible . Otherwise, submit proposals . - Name and address of depot: Submit before any concrete is delivered . - Delivery notes: Retain for inspection . • Declarations of nonconformity from concrete producer: Notify immediately .

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221 INFORMATION ABOUT PROPOSED CONCRETES • Submit when requested: - Details listed in BS 8500-1, clause 5.2. - Additional information: Data concerning the anticipated rate of strength gain.

225 CHANGES TO SPECIFICATION • Changes to specification of fresh concrete (outside concrete producer's responsibility): Pro hibited.

230 INTERRUPTION OF SUPPLY DURING CONCRETING • Elements without joints: Where elements are detailed to be cast in a single pour without joints, make prior arrangements for a back-up supply of concrete. • Elsewhere: - Preparation: Manage pour to have a full face, and have materials available to form an emergency construction joint while concrete can still be worked. - Before pour is completed: Submit location and details of joint, make proposals for joint preparation.

310 RECYCLED AGGREGATE • Standard: To BS 8500-2, clause 4.3 and BS EN 12620. • Type: Recycled concrete to table 2 BS8500-2. • Source: submit proposals. • Quality control: To WRAP guidance. • Limitations on use: - Concrete strength class (maximum): C32/40 maximum. - Permitted exposure classes: to table 3 BS8500-2. • Additional restrictions on content: - Acid-soluble sulfate content (maximum): Category ASo,2. - Alkali-aggregate reactivity: Do not use aggregate containing reactive silica. • Test method: - Determination of chloride content: To BS EN 1744-5. - Determination of alkali content: Not applicable. • Frequency of testing: 1 sample per 100cu of material. • Other requirements: None.

415 ADMIXTURES • Calcium chloride and admixtures containing calcium chloride: Do not use .

490 PROPERTIES OF FRESH CONCRETE • Adjustments to suit construction process: Determine with concrete producer . Maintain conformity to the specification .

PROJECT TESTING/ CERTIFICATION

505 PROJECT TESTING OF CONCRETE - GENERAL • Testing: To BS 8500-1, Annex B. - Nonconformity: Obtain instructions immediately. • Recording: Maintain complete correlated records including: - Concrete designation. - Sampling, site tests, and identification numbers of specimens tested in the laboratory. - Location of the parts of the structure represented by each sample. Location in the structure of the batch from which each sample is taken.

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508 REGULAR PROJECT TESTING OF CONCRETE • Tests: Compressive strength and Early age compressive strength testing at 7, 14 and 28 days. • Sampling: - Point: At point of discharge from delivery truck. - Rate: One sample per 20 m³. • Other requirements: Cubes for early age strength testing to be stored under same conditions as concrete in members.

520 TESTING LABORATORY • Laboratory: Accredited by UKAS or other national equivalent. - Name and UKAS reference number: Submit well in advance of making trial mixes or concrete for use in the works.

530 TESTS RESULTS • Submission of reports: Within one day of completion of each test. - Number of copies: one. • Reports on site: A complete set, available for inspection.

550 BROKEN CUBES FROM FAILED STRENGTH TESTS • Nonconformity: Keep separately the pieces of each cube which fail to meet the conformity requirements for individual results. • Period for keeping cubes: Obtain instructions.

PLACING/ COMPACTING/ CURING AND PROTECTING

630 PREMATURE WATER LOSS • Requirement: Prevent water loss from concrete laid on absorbent substrates . - Underlay: Select from: Polyethylene sheet: 250 micrometres thick . Building paper: To BS 1521, grade B1F . - Installation: Lap edges 150 mm .

640 CONSTRUCTION JOINTS • Location of joints: Submit proposals when not shown on drawings. • Preparation of joint surfaces: Remove surface laitance and expose aggregate by lightly brushing and spraying. Joint surface to be clean and damp immediately before placing fresh concrete.

648 ADVERSE TEMPERATURE CONDITIONS • Requirement: Submit proposals for protecting concrete when predicted ambient temperatures indicate risk of concrete freezing or overheating.

650 SURFACES TO RECEIVE CONCRETE • Cleanliness of surfaces immediately before placing concrete: Clean with no debris, tying wire clippings, fastenings or free water .

660 INSPECTION OF SURFACES • Notice: Give notice to allow inspections of reinforcement and surfaces before each pour of concrete. - Period of notice: Obtain instructions. • Timing of inspections: First inspection when reinforcement fixing is close to completion,.

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670 TRANSPORTING • General: Avoid contamination, segregation, loss of ingredients, excessive evaporation and loss of workability . Protect from heavy rain . • Entrained air: Anticipate effects of transport and placing methods in order to achieve specified air content .

680 PLACING • Records: Maintain for time, date and location of all pours. • Timing: Place as soon as practicable after mixing and while sufficiently plastic for full compaction. • Temperature limitations for concrete: 30°C (maximum) and 5°C (minimum), unless otherwise specified. Do not place against frozen or frost covered surfaces. • Continuity of pours: Place in final position in one continuous operation up to construction joints. Avoid formation of cold joints. • Discharging concrete: Prevent uneven dispersal, segregation or loss of ingredients or any adverse effect on the formwork or formed finishes. • Thickness of layers: To suit methods of compaction and achieve efficient amalgamation during compaction. • Poker vibrators: Do not use to make concrete flow horizontally into position, except where necessary to achieve full compaction under void formers and cast-in accessories and at vertical joints.

690 COMPACTING • General: Fully compact concrete to full depth to remove entrapped air. Continue until air bubbles cease to appear on the top surface. - Areas for particular attention: Around reinforcement, under void formers, cast-in accessories, into corners of formwork and at joints. • Consecutive batches of concrete: Amalgamate without damaging adjacent partly hardened concrete. • Methods of compaction: To suit consistence class and use of concrete.

720 VIBRATORS • General: Maintain sufficient numbers and types of vibrator to suit pouring rate, consistency and location of concrete . • External vibrators: Obtain approval for use .

730 PLASTIC SETTLEMENT • Settlement cracking: Inspect fresh concrete closely and continuously wherever cracking is likely to occur, including the top of deep sections and at significant changes in the depth of concrete sections . - Timing: During the first few hours after placing and whilst concrete is still capable of being fluidized by the vibrator . • Removal of cracks: Revibrate concrete.

810 CURING GENERALLY • Requirement: Keep surface layers of concrete moist throughout curing period, including perimeters and abutments, by either restricting evaporation or continuously wetting surfaces of concrete. - Surfaces covered by formwork: Retain formwork in position and, where necessary to satisfy curing period, cover surfaces immediately after striking. - Top surfaces: Cover immediately after placing and compacting. If covering is removed for finishing operations, replace it immediately afterwards. • Surface temperature: Maintain above 5°C throughout the specified curing period or four days, whichever is longer. • Records: Maintain details of location and timing of casting of individual batches, removal of formwork and removal of coverings. Keep records on site, available for inspection.

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811 COVERINGS FOR CURING • Sheet coverings: Suitable impervious material . • Curing compounds: Selection criteria: - Curing efficiency: Not less than 75% or for surfaces exposed to abrasion 90% . - Colouring: Fugitive dye . - Application to concrete exposed in the finished work: Readily removable without disfiguring the surface . - Application to concrete to receive bonded construction/ finish: No impediment to subsequent bonding . • Interim covering to top surfaces of concrete: Until surfaces are in a suitable state to receive coverings in direct contact, cover with impervious sheeting held clear of the surface and sealed against draughts at perimeters and junctions .

812 PREVENTING EARLY AGE THERMAL CRACKING • Deep lifts or large volume pours: Submit proposals for curing to prevent early age thermal cracking, taking account of: - Temperature differentials across sections . - Coefficient of thermal expansion of the concrete . - Strain capacity of the concrete mix (aggregate dependent) . - Restraint .

815 ADDITIONAL CURING REQUIREMENT - WATER CURING • Commencement of water curing: As soon as practicable after placing and compacting concrete . - Surfaces covered by formwork: Expose to water curing as soon as practicable . - Top surfaces: Cover immediately with impermeable sheeting to prevent evaporation before commencement of water curing . • Water curing: Wet surfaces continuously throughout curing period . - Select methods from: Mist spray . Wet hessian covered with impermeable sheeting .

818 CURING PERIODS GENERALLY • Minimum periods: When not otherwise indicated, to BS EN 13670, Annex F.8.5.

840 PROTECTION • Prevent damage to concrete, including: - Surfaces generally: From rain, indentation and other physical damage . - Surfaces to exposed visual concrete: From dirt, staining, rust marks and other disfiguration . - Immature concrete: From thermal shock, physical shock, overloading, movement and vibration . - In cold weather: From entrapment and freezing expansion of water in pockets, etc .

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E20

Formwork for in situ concrete


E20 Formwork for in situ concrete

To be read with Preliminaries/ General conditions.

GENERALLY/ PREPARATION

110 LOADINGS • Requirement: Design and construct formwork to withstand the worst combination of the following: - Total weight of formwork, reinforcement and concrete. - Construction loads including dynamic effects of placing, compacting and construction traffic. Wind and snow loads.

132 PROPPING • General: Prevent deflection and damage to the structure. Carry down props to bearings strong enough to provide adequate support throughout concreting operations. • Method statement: Submit proposals for prop bearings and sequence of propping/ repropping and backpropping. - Timing of submission: To be agreed between the permanent works designer and the temporary works coordinator .

170 WORK BELOW GROUND- BASES • Casting vertical faces against faces of excavation: Permitted provided face of excavation is stable. - Requirements: Increase width of section to give nominal cover to reinforcement of 75 mm.

CONSTRUCTION

310 ACCURACY • General requirement for formwork: Accurately and robustly constructed to produce finished concrete in the required positions and to the required dimensions. • Formed surfaces: Free from twist and bow (other than any required cambers). • Intersections, lines and angles: Square, plumb and true.

315 SUBSTRUCTURE FORMWORK AND UNDERSLAB INSULATION • Cutting: Neat and accurate to edges, and around penetrations and downstands. • Laying: Tightly butted and fully supported on firm, even substrate. • Vertical faces: Stiffen as necessary to act as shutter. • Formwork/ insulation surfaces: Protect from indentation by spacers and other items. • Joints in formwork/ insulation and with edge structure and penetrations: Seal to prevent penetration of concrete. • Concrete placement: Restrain formwork/ insulation against movement.

320 JOINTS IN FORMS • Requirements including joints in form linings and between forms and completed work: - Prevent loss of grout, using seals where necessary. Prevent formation of steps. Secure formwork tight against adjacent concrete.

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330 INSERTS, HOLES AND CHASES • Positions and details: - Dimensioned on drawings provided on behalf of the Employer: Do not change without consent. - Undimensioned or from other sources: Submit proposals. • Positioning relative to reinforcement: Give notice of any conflicts well in advance of placing concrete. • Method of forming: Fix inserts or box out as required. Do not cut hardened concrete without approval.

340 KICKERS • Method statement: Submit proposals including means of achieving quality of concrete consistent with that specified for the column or wall. Kicker height: As drawings.

350 FORM TIES • Metal associated with form ties/ devices: Prohibited within cover to reinforcement. Compatible with reinforcement metal.

470 RELEASE AGENTS • Use: All formwork. • General: Achieve a clean release of forms without disfiguring the concrete surface. • Product types: Compatible with formwork materials, specified formed finishes and subsequent applied finishes. Use the same product throughout the entire area of any one finish. • Protection: Prevent contact with reinforcement, hardened concrete, other materials not part of the form face, and permanent forms.

STRIKING

510 STRIKING FORMWORK • Timing: Prevent any disturbance, damage or overloading of the permanent structure.

521 MINIMUM PERIOD FOR RETAINING FORMWORK/ TEMPORARY SUPPORTS IN POSITION • Concrete strength at time of formwork removal (minimum): 70% of 28 day strength. • Assumptions: Maturity of permanent supports and adjacent elements of structure is at least equal to element under consideration. - Before removing formwork: Submit proposals if assumptions will not be realised. • Method to be used in assessing early age strength of concrete: Submit proposals.

FORMED FINISHES

610 BASIC FINISH • Location: Faces below ground level. • Finish: Faces fully compacted and cover to reinforcement provided.

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E30

Reinforcement for in situ concrete


E30 Reinforcement for in situ concrete


REINFORCEMENT

110 QUALITY ASSURANCE OF REINFORCEMENT • Standards: - Reinforcement: To BS 4449, BS 4482, BS 4483 or BS 6744. - Cutting and bending: To BS 8666. • Source of reinforcement: Companies holding valid certificates of approval for product conformity issued by the UK Certification Authority for Reinforcing Steels (CARES).

150 RIBBED BAR REINFORCEMENT • Standard: To BS 4449. Strength grade: Generally B500B, but B500C where detailed.

210 STANDARD FABRIC REINFORCEMENT • Standard: To BS 4483. • Strength grade: B500A min.

WORKMANSHIP

310 CUTTING AND BENDING REINFORCEMENT • General: To schedules and to BS 8666. • Bending on site, including minor adjustments: Obtain instructions.

320 PROTECTION OF REINFORCEMENT • Dropping from height, mechanical damage and shock loading: Prevent. • Cleanliness of reinforcement at time of pouring concrete: Free from corrosive pitting, loose mill scale, loose rust and contaminants which may adversely affect the reinforcement, concrete, or bond between the two.

410 LAPS OR SPLICES • Details not shown on drawings: Obtain instructions.

425 LAPS NOT DETAILED ON DRAWINGS • Laps in bar reinforcement (minimum): Generally 40 x bar diameter. • Laps in fabric reinforcement (minimum): 450 mm. - Laps at corners: Avoid four layer build-up.

427 LAPS IN FABRIC REINFORCEMENT • Terms: As defined in BCA publication 97.321. • Lap type: - Long edge of fabric: Flying end laps. - Short edge of fabric: Reverse layer lap with bars in centre layer bundled and bars in outer layers spaced apart to ensure full encapsulation in concrete. • Other requirements: Stagger end laps.

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451 FIXING REINFORCEMENT • Standard: To BS 7973-1 and -2. • Installation: In addition to any spacers and chairs shown on drawings or schedules, provide adequate support, tie securely and maintain the specified cover. • Tying: - Wire type: 16 gauge black annealed. Use stainless steel wire for stainless steel reinforcement. - Ends of tying wire: Prevent intrusion into the concrete cover. Remove loose ends. • Compatibility of metals: Prevent contact between ordinary carbon steel and stainless or galvanized reinforcement.

470 TOLERANCES ON COVER • Tolerance (maximum): -10mm . • Checking specified cover dimensions: Before concreting check that cover dimensions will be achieved.

480 NOMINAL COVER TO REINFORCEMENT • Top face: Generally 30mm but 40mm for foundations. • Formed faces: Generally 50 mm but 75 for surfaces cast against soil.

510 RUST STAINING • Staining of surfaces of concrete which will be exposed to view in the finished work: Prevent.

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E40

Designed joints in in situ concrete


E40 Designed joints in in situ concrete


120 CONSTRUCTION/ MOVEMENT JOINTS GENERALLY • Accuracy: Position and form joints accurately, straight, well-aligned and truly vertical or horizontal or parallel with setting out lines of the building. • Modifications to joint design or location: Submit proposals. • Placing concrete to form movement joints: - Maintain effectiveness of joints. Prevent concrete entering joints or penetrating or impregnating compressible joint fillers. Do not place concrete simultaneously on both sides of movement joints.

132 ADDITIONAL CONSTRUCTION JOINTS • Joints additional to those required by designer: Permitted, but subject to restrictions in section E10 . • Approval of additional joints: Submit proposals.

210 FORMED JOINTS • Forms/ stop ends generally: Rigid and grout-tight. • Forms/ stop ends for projecting continuity reinforcement: To accommodate bars or fabric without temporary bending or displacement.

230 PREPARATION OF CONSTRUCTION JOINTS • Roughening of joint surfaces: Select from: - Brushing and spraying: Remove surface laitance and expose aggregate finish while concrete is still green. - Other methods: Submit proposals. • Condition of joint surfaces immediately before placing fresh concrete: Clean and damp.

520 SHEET JOINT FILLERFOR ISOLATION JOINTS • Manufacturer: Submit proposals. - Product reference: Submit proposals. • Joints finished with sealant: Leave sufficient space for sealant by using temporary formers.

530 SEALANTfor slab joints • Manufacturer: Submit proposals. - Product reference: Submit proposals. - Colour of surfaces exposed to view: tbc. • Preparation and application: As section Z22.

545 COMPRESSIBLE SEALING STRIP SYSTEM for slab joints • Manufacturer: submit proposals. - Product reference: submit proposals. Colour: tbc.

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E41

Worked finishes to in situ concrete


E41 Worked finishes to in situ concrete


150 FINISHING • Timing: Carry out at optimum times in relation to setting and hardening of concrete. • Prohibited treatments to concrete surfaces: - Wetting to assist surface working. Sprinkling cement.

230 BRUSHED FINISH • Surface on completion: Light even texture.

240 WOOD FLOATED FINISH • Surface on completion: Slightly coarse, even texture with no ridges or steps.

310 SMOOTH FLOATED FINISH • Surface on completion: Even with no ridges or steps.

320 TROWELLED FINISH • Surface on completion: Uniform, smooth but not polished, free from trowel marks and blemishes, and suitable to receive specified flooring material.

520 SURFACE SEALER • Manufacturer: Submit proposals. - Product reference: Submit proposals. • Substrate: - Moisture content: As recommended by sealer manufacturer. Test relative humidity to BS 8203, Annex A where required to verify suitability. - Condition prior to application: Cured, clean and free from contaminants. • Primer: Not required. • Application: Evenly to dry surfaces to form an effective seal but without a glossy finish.

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E60

Precast/ composite concrete floors/ roof decks


E60 Precast/ composite concrete floors/ roof decks


PROPRIETARY FLOORS/ ROOF DECKS

110 PRECAST BEAM AND BLOCKFLOOR • Beams: To be designed by specialist sub-contractor. A preliminary specification has been provided on the drawings. - Manufacturer: Submit proposals. Product reference: Submit proposals. - Type: Submit proposals. • Infill blocks: Proprietary. • Structural concrete topping: Not required. • Other requirements: None.

GENERAL/ PERFORMANCE

240 DETAILING OF PROPRIETARY SYSTEM • Installation details: Submit location and assembly drawings showing every aspect of the construction, incorporated components and features, trimming for voids, holes for services, and related work by others. - Purpose: To allow checking of compatibility with surrounding structure and coordination of services. • Method statement and risk assessment for installation: Submit. • Programme: Submit well in advance of construction.

INSTALLATION

325 GROUTING • Mix: Contractor's choice. • Preparation: Thoroughly clean and wet surfaces. • Fill all joints and surface irregularities.

350 LEVELS OF STRUCTURAL CONCRETE FLOORS • Tolerances: See Preliminaries section A33.

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F

Masonry

F10

Brick/ block walling


F10 Brick/ block walling


TYPES OF WALLING

110 CLAY FACING BRICKWORKAbove DPC • Bricks: To BS EN 771-1. - Manufacturer: Refer to Architect's specification. Product reference: Refer to Architect's specification. - Recycled content: Refer to Architect's specification. - Special shapes: Refer to Architect's specification. • Mortar: As section Z21. - Standard: To BS EN 998-2. - Mix: 1:1:6 cement:lime:sand 4 N/mm² (mortar class 4). - Additional requirements: For any colour preferences refer to Architect's specification . • Bond: Half lap stretcher. • Joints: Refer to Architect's specification. • Features: Refer to Architect's specification.

110A CLAY FACING BRICKWORKBelow DPC • Bricks: To BS EN 771-1. - Manufacturer: Refer to Architect's specification. Product reference: Refer to Architect's specification. - Recycled content: Refer to Architect's specification. - Special shapes: Refer to Architect's specification. • Mortar: As section Z21. - Standard: To BS EN 998-2. - Mix: 1:3 masonry cement:sand 6 N/mm² (mortar class 6). - Additional requirements: For any colour preferences refer to Architect's specification . • Bond: Half lap stretcher. • Joints: Refer to Architect's specification. • Features: Refer to Architect's specification.

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355 CONCRETE COMMON BLOCKWORKto internal walls and inner leaf of cavity walls where shown on architect's drawings • Blocks: To BS EN 771-3. - Manufacturer: Contractor's choice. Product reference: Submit proposals. - Configuration: Group 1. - Compressive strength: Mean value: 3.6 N/mm² and 7.3n/mm2. Characteristic value: Not applicable. Category: I. - Freeze/ Thaw resistance: Frost resistant. - Thermal properties: To architect's specification. - Recycled content: Submit proposals. - Work sizes (length x width x height): 440 x 100 x 215 mm and 440 x 140 x 215mm. Tolerance category: D1. - Special shapes: None. - Additional requirements: Reaction to fire class: A1. Paint grade appearance. • Mortar: As section Z21. - Standard: To BS EN 998-2. - Mix: 1:1:6 cement:lime:sand 4 N/mm² (mortar class 4). - Additional requirements: None. • Bond: Half lap stretcher.

385 ENGINEERING BRICKWORK For use in manholes; as drainage cover support; for below ground construction to dupplex retaining walls; as dpc to external walls • Bricks: To BS EN 771-1. - Manufacturer: Contractor's choice. Product reference: Submit proposals. - Type: HD. - Mean compressive strength: Greater than or equal to 75 N/mm². Category: I. - Water absorption: Equal to or less than. 7.5%. - Freeze/ Thaw category: F2. - Active soluble salts content category: S2. - Additional requirements: None. • Mortar: As section Z21. - Standard: To BS EN 998-2. - Mix: 1:0.25:3 cement:lime:sand, 12 N/mm² (mortar class 12). - Additional requirements: None. • Bond: Half lap stretcher. • Joints: Flush.

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395 DAMP PROOF COURSE BRICKWORK • Bricks to BS EN 771-1. - Manufacturer: Contractor's choice. Product reference: Submit proposals. - Type: HD. - Water absorption: Equal to or less than 4.5%. - Net dry density: Equal to or greater than 2100 kg/m³. - Freeze/ Thaw category: F2. - Active soluble salts content category: S2. - Additional requirements: None. • Mortar: As section Z21. - Standard: To BS EN 998-2. - Mix: 1:0.25:3 cement:lime:sand, 12 N/mm² (mortar class 12). - Additional requirements: None. • Bond: English garden wall or half lap stretcher depending on location . • Joints: Bucket handle.

WORKMANSHIP GENERALLY

430 CONDITIONING OF CLAY AND CALCIUM SILICATE BRICKS AND CLAY BLOCKS • Bricks and blocks delivered warm from manufacturing process: Do not use until cold. • Absorbent bricks in warm weather: Wet to reduce suction. Do not soak.

440 CONDITIONING OF CONCRETE BRICKS/ BLOCKS • Autoclaved concrete bricks/ blocks delivered warm from manufacturing process: Do not use. • Age of nonautoclaved concrete bricks/ blocks: Do not use until at least four weeks old. • Avoidance of suction in concrete bricks/ blocks: Do not wet. - Use of water retaining mortar admixture: Submit details.

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460 MORTAR GROUPS • Mix proportions: For a specified group select a mix design from the following: - Group 1: 1:0–0.25:3 (Portland cement:lime:sand with or without air entraining additive). 1:3 (Portland cement:sand and air entraining additive). - Group 2: 1:0.5:4–5 (Portland cement:lime:sand with or without air entraining additive). 1:3 (masonry cement:sand containing Portland cement and lime in approximate ratio 1:1, and an air entraining additive). 1:2.5–3.5 (masonry cement:sand containing Portland cement and inorganic materials other than lime and air entraining additive). 1:3–4 (Portland cement:sand and air entraining additive.) - Group 3: 1:1:5–6 (Portland cement:lime:sand with or without air entraining additive). 1:3.5–4 (masonry cement:sand containing Portland cement and lime in approximate ratio 1:1, and an air entraining additive). 1:4–5 (masonry cement:sand containing Portland cement and inorganic materials other than lime and air entraining additive). 1:5–6 (Portland cement:sand and air entraining additive). - Group 4: 1:2:8–9 (Portland cement:lime:sand with or without air entraining additive). 1:4.5 (masonry cement:sand containing Portland cement and lime in approximate ratio 1:1, and an air entraining additive). 1:5.5–6.5 (masonry cement:sand containing Portland cement and inorganic materials other than lime and air entraining additive). 1:7–8 (Portland cement:sand and air entraining additive). • Batching: Mix proportions by volume. • Mortar type: Continuous throughout any one type of masonry work.

500 LAYING GENERALLY • Mortar joints: Fill vertical joints. Lay bricks, solid and cellular blocks on a full bed. • AAC block thin mortar adhesive and gypsum block adhesive joints: Fill vertical joints. Lay blocks on a full bed. • Clay block joints: - Thin layer mortar: Lay blocks on a full bed. - Interlocking perpends: Butted. • Bond where not specified: Half lap stretcher. • Vertical joints in brick and concrete block facework: Even widths. Plumb at every fifth cross joint.

520 ACCURACY • Courses: Level and true to line. • Faces, angles and features: Plumb. • Permissible deviations: - Position in plan of any point in relation to the specified building reference line and/ or point at the same level ± 10 mm. - Straightness in any 5 m length ± 5 mm. - Verticality up to 3 m height ± 10 mm. - Verticality up to 7 m height ± 14 mm. - Overall thickness of walls ± 10 mm. - Level of bed joints up to 5 m (brick masonry) ± 11 mm. - Level of bed joints up to 5 m ± 13 mm.

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535 HEIGHT OF LIFTS IN WALLING USING CEMENT GAUGED OR HYDRAULIC LIME MORTAR • Quoins and advance work: Rack back. • Lift height (maximum): 1.2 m above any other part of work at any time. • Daily lift height (maximum): 1.5 m for any one leaf.

545 LEVELLING OF SEPARATE LEAVES • Locations for equal levelling of cavity wall leaves: As follows: - Every course containing vertical twist type ties or other rigid ties. - Every third tie course for double triangle/ butterfly ties. Courses in which lintels are to be bedded.

560 COURSING BRICKWORK • Gauge: Four brick courses including bed joints to 300 mm.

580 LAYING FROGGED BRICKS • Single frogged bricks: Frog uppermost. • Double frogged bricks: Larger frog uppermost. • Frog cavity: Fill with mortar.

595 LINTELS • Bearing: Ensure full length masonry units occur immediately under lintel ends.

615 BRICKWORK TO RECEIVE ASPHALT DPC • Substrate: Mortar bed finished flush, smooth and level.

635 JOINTING • Profile: Consistent in appearance.

645 ACCESSIBLE JOINTS NOT EXPOSED TO VIEW • Jointing: Struck flush as work proceeds.

690 ADVERSE WEATHER • General: Do not use frozen materials or lay on frozen surfaces. • Air temperature requirements: Do not lay bricks/ blocks: - In cement gauged mortars when at or below 3°C and falling or unless it is at least 1°C and rising. - In hydraulic lime:sand mortars when at or below 5°C and falling or below 3°C and rising. - In thin joint mortar glue when outside the limits set by the mortar manufacturer. • Temperature of walling during curing: Above freezing until hardened. • Newly erected walling: Protect at all times from: - Rain and snow. - Drying out too rapidly in hot conditions and in drying winds.

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F30

Accessories/ sundry items for brick/ block/ stone walling


F30 Accessories/ sundry items for brick/ block/ stone walling


CAVITIES

120 CLEANLINESS • Cavity base and faces, ties, insulation and exposed dpcs: Free from mortar and debris.

REINFORCING/ FIXING ACCESSORIES

210 CAVITY WALL TIESGENERALLY • Standard: To DD 140-2. - Type: 2 (Masonry general purpose) . • Material/ finish: Stainless steel . • Sizes: 200 mm .

214 CAVITY WALL TIESTying back to SFS inner leaf • Standard: To BS EN 845-1. - Type: 2 (Masonry general purpose). • Manufacturer: Ancon or similar. - Product reference: SD25. • Material/ finish: Austenitic stainless steel. • Sizes: to suit cavity width. • End types: Symmetrical pierced deformed plate. • Design embedment length (minimum): 60 mm. • Movement: Tolerant. • Additional requirements: Fit ties into 25/14 channel fixed back to SFS - subject to confirmation of insulation 'stiffness'..

225A FIXING TIES IN MASONRY CAVITY WALLS • Embedment in mortar beds (minimum): 50 mm where tying two masonry leaf; 60mm where tying masonry to SFS. • Placement: Sloping slightly downwards towards outer leaf, without bending. Drip centred in the cavity and pointing downwards. • Spacing - two masonry leafs: Staggered in alternate courses. - Horizontal centres: 900 mm . - Vertical centres: 450 mm . Spacing: Masonry to SFS - Horizontal centres: [to suit SFS spacing but no more than 600mm] . - Vertical centres: [450mm] . • Additional ties: Provide within 225 mm of reveals of unbonded openings. - Spacing: At not more than 300 mm centres vertically .

241 WALL STARTERS/ CONNECTORS • Manufacturer: Ancon Building Products or similar. - Product reference: Staifix Universal Wall starter system. • Material/ finish: Austenitic stainless steel. • Sizes: as manufacturer's standard.

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241A WALL STARTERS/ CONNECTORS For fixing masonry walls to steel frames • Manufacturer: Ancon or similar. - Product reference: SPB, SDB. • Material/ finish: Austenitic stainless steel. • Sizes: to suit minimum embedment of 65mm into masonry. • Vertical centres - 450mm • Isolate tie from steelwork using neoprene gaskets • Fix to steel using 5mm self tapping screws

242A SURFACE MOUNTED CHANNELS/ SLOTS For fixing to SFS framing, concrete columns and walls (for concrete this is an option in lieu of clause 241) • Manufacturer: Ancon Building Products or similar. - Product reference: 25/14. • Material: Austenitic stainless steel. • Type: Plain back. • Profile: Manufacturer's standard. • Size (width x depth): 25 x 14 mm. • Length: To suit work area. • Fixing: Manufacturer's standard.

245 CHANNEL/ SLOT TIESAs clause 214 • Standard: To BS EN 845-1. • Manufacturer: Ancon. - Product reference: SD25. • Material/ finish: Austenitic stainless steel. • Sizes: to suit cavity and minimum embedment listed below. • Channel/ slot fixing: Surface. • End types: Asymmetrical sliding tee slot end with deformed plate embedment end. • Design embedment length (minimum): 60 mm. • Additional requirements: None.

270 MESHWORK JOINT REINFORCEMENTGENERALLY • Standard: To BS EN 845-3. • Manufacturer: Ancon. - Product reference: AMR. • Type: Welded wire ladder type. • Material: Austenitic stainless steel. • Width: Approximately 40-50 mm less in width than wall or leaf. • Placement: Lay on an even bed of mortar in a continuous strip with full laps at angles. Keep back 20 mm from face of external work, 12 mm back from face of internal work and finish joint to normal thickness. - Lap length (minimum): 200.

282 GENERAL PURPOSE SLIP TIES FOR MOVEMENT JOINTS To masonry as shown on the drawings • Standard: To BS EN 845-1. • Manufacturer: Ancon Building Products. - Product reference: PPS. • Material/ finish: Austenitic stainless steel. • Sizes: 225long . • Shear load capacity: not less than 750N . • End types: Symmetrical flat plate with slip case . • Design embedment length (minimum): 50 mm . • Additional requirements: None . • Fixing centres: 450mm vertical .

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FLEXIBLE DAMP PROOF COURSES/ CAVITY TRAYS

360 GAS RESISTANT DPCS/ CAVITY TRAYS • Manufacturer: Refer to Architects Specification. - Product reference: Refer to Architects Specification.

INSTALLATION OF DPCS/ CAVITY TRAYS

415 HORIZONTAL DPCS • Placement: In continuous lengths on full even bed of fresh mortar, with 100 mm laps at joints and full laps at angles. • Width: At least full width of leaf unless otherwise specified. Edges of dpc not covered with mortar or projecting into cavity. • Overlying construction: Immediately cover with full even bed of mortar to receive next masonry course. • Overall finished joint thickness: As close to normal as practicable.

435 STEPPED DPCS IN EXTERNAL WALLS • External walls on sloping ground: Install dpcs not less than 150 mm above adjoining finished ground level.

495 GAS RESISTANT DPCS/ CAVITY TRAYS • Joint treatment: Use unjointed wherever possible, otherwise lap at least 150 mm and seal to form a gas and watertight installation. • Joint with damp proof membrane: Overlap dpc/ cavity tray not less than 150 mm.

JOINTS

610 MOVEMENT JOINTS WITH SEALANTTO EXTERNAL FACING BRICKWORK • Joint preparation and sealant application: As section Z22. • Filler: Closed cell polyethylene foam. - Thickness: To match design width of joint. - Manufacturer: Grace Construction Products. - Product reference: Aerofil 1. - Placement: Build in as work proceeds with no projections into cavities and to correct depth to receive sealant system. • Sealant: - Designation: ISO 11600-F-25LM. - Manufacturer: Sika. - Product reference: Hybriflex 825. - Colour: To Architect Specification.

610A MOVEMENT JOINTS WITH SEALANTTo internal blockwork walls - see also 616 • Joint preparation and sealant application: As section Z22. • Filler: Closed cell polyethylene foam- either full depth or bead system.. - Thickness: To match design width of joint. - Manufacturer: Grace Construction Products. - Product reference: Aerofil 1. - Placement: Build in as work proceeds with no projections into cavities and to correct depth to receive sealant system. • Sealant: - Designation: ISO 11600-F-25LM. - Manufacturer: Sika. - Product reference: Hybriflex 825. Colour: To Architect Specification.

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616 FIRE RESISTANT MOVEMENT JOINTS WITHOUT SEALANTTO INTERNAL FACING BLOCKWORK ON FIRE COMPARTMENT LINES - vertical and horizontal • Fire resistant filler: - Thickness: to suit gap wdth. - Fire resistance period: 60mins. - Manufacturer: Nullifire - Unless alternative specified by Architect. - Product reference: FJ200. - Placement: Compress and insert into place in open joint. Adhesives and accessories: Types recommended by filler manufacturer.

630 UNEXPOSED CONTRACTION JOINTS • Formation: Close butt as work proceeds.

650 POINTING IN FLASHINGS • Joint preparation: Free of debris and lightly wetted. • Pointing mortar: As for adjacent walling. • Placement: Fill joint and finish flush.

660 PINNING UP TO SOFFITS • Top joint of loadbearing walls: Fill and consolidate with mortar.

670 TOPS OF NONLOADBEARING WALLS • Restraints: as Cl 251 . - Fixing: Secure to soffit. • Joint filler: As 610A for non fire compartment walls and 616 for fire compartment walls . - Placement: Full, no gaps.

PROPRIETARY SILLS/ LINTELS/ COPINGS/ DRESSINGS

735 PRECAST CONCRETE LINTELS • Standard: To BS EN 845-2. • Manufacturer: Naylor or similar. - Product reference: Hi-spec or fairfaced. • Types: Single. • Sizes: As indicated on the drawing • Additional requirements: Freeze/ thaw: Resistant for lintels below dpc. • Placement: Bed on mortar used for adjacent work. - Bearing length (minimum): 150 mm.

745 PRESTRESSED CONCRETE LINTELS • Standard: To BS EN 845-2. • Manufacturer: Naylor or similar. - Product reference: Fairfaced, Hi-spec or Fire Specification . • Types: Single. • Sizes: As drawings. • Additional requirements: Freeze/ thaw: Resistant for lintels below DPC in external walls. • Placement: Bed on mortar used for adjacent work. Prop at not more than 1.2 m centres to prevent displacement during construction. Retain props in position for not less than 14 days or until mortar has matured, whichever is longer. Bearing length (minimum): 150 mm.

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755 PREFABRICATED STEEL LINTELS • Standard: To BS EN 845-2. • Manufacturer: Birtley or similar. - Product reference: Supergalv EV series. • Types: Single. • Material/ finish: Zinc coated steel to BS EN ISO 1461 with minimum coating mass of 460 g/m², coating minimum thickness of 65 micrometres with organic coating type 1, 25 micrometres thick to all surfaces indicated in figure C1 of BS EN 845-2. • Sizes: As drawing. • Additional requirements: Lintels to be propped during construction unitl supported masonry joints have cured.. • Placement: Bed on mortar used for adjacent work. Bearing length (minimum): 150 mm.

MISCELLANEOUS ITEMS

830 BUILDING IN FRAMES • Preparation: Remove horns and provide support. • Fixing cramps: Fully bed in mortar.

840 OPENINGS FOR FRAMES • Formation: Use accurate, rigid templates to required size.

850 WALL PLATES • Placement: On full bed of mortar to correct horizontal level.

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G

Structural/Carcassing metal/timber

G10

Structural steel framing


G10 Structural steel framing


GENERAL REQUIREMENTS/ INFORMATION

101A SITE REQUIREMENTS • General: Become fully acquainted with the full nature of the work, the location and character of the site and means of access to the site, including any traffic restrictions imposed. Refer to Kier Construction Eastern Design Manager for site specific details .

105A COMPLIANCE • General: Ensure the compliance of all design, workmanship, materials and testing (where required) with the appropriate British Standards, Eurocode and with the drawings. All codes of practice referred to in this specification shall be the latest revised editions with amendments to BS5950 or EC3.

110 CONTRACTOR'S DESIGN OF JOINTS All connections to be designed to BS 5950 • Design concept: Single storey frame with lateral stability provided by a combination of braced bays and rigid frames. • Design responsibility: Design connections and detail steelwork and connections. - Other responsibilities: Contractors design of all steelwork required for erection. • Structural requirements: - Generally: As section B50. Modifications: None. - Design: Complete in accordance with the designated code of practice to satisfy specified performance criteria. - Connections: Design and detail joints to designated code of practice. - Fixings to foundations and walls: Design and detail fixings to concrete to designated code of practice. - Additional requirements: None. • Design and production information: Submit to Engineer prior to comencing fabrication. A full drawing and calculation package will be required for submission to Building Control.

113A DIMENSIONS . • The steel fabricator is to undertake a site survey to obtain and check dimensions prior to fabrication of steelwork. Any dimensions indicated on drawings are to be checked on site

prior to fabrication of steelwork .

115 DESIGN CONSTRAINTS - GENERAL • Members forming bracing systems or girders of lattice construction: Unless detailed or instructed otherwise, position so that their lines of action intersect at a point. • Bolts: - Diameter (minimum): 20 mm for primary structural members, 16mm for secondary steelwork. - Number per connection (minimum): Two, unless otherwise indicated. - Other requirements: Choose bolt dimensions to ensure that threads do not occur in shear plane of joint. • Punching of bolt holes: Not permitted. • Welds: To be designed by the Contractor. All welds to be minimum 6mm FW.. • Other constraints: None.

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116 DESIGN CONSTRAINTS - STEELWORK TO BE GALVANIZED • Steel grades: Do not use steel downgraded from a higher specification. • Detail design: Avoid details that will increase the risk of initiating liquid metal assisted cracking (LMAC). - Particular restrictions: Use bolted cleat connections and Use intermittent welds when design permits. • Other requirements: Seal vent and drainage holes in hollow sections using non-ferrous plugs.

121A CONNECTION DETAILS AND CALCULATIONS • General: Submit 2 copies of all typical and special connection details together with supporting calculations for approval prior to the preparation of the shop drawings. Allowing at least 10 working days for their review. These details are to be A3 format (max).

123 DRAWINGS AND CALCULATIONS PREPARED BY CONTRACTOR • Information required: Bracing and phasing assumptions to be agreed with Kier Design Manager and Kier Structural Engineers. • General arrangement drawings: Submit before preparing calculations. Clearly identify: - Individual steel members. - Conflicts with other work. - Proposed changes to contract drawings. • Member and joint calculations: Submit before preparing fabrication drawings.

125A SPECIFICATION STANDARD • Standard: Comply with latest edition of National Structural Steelwork Specification (NSSS). - Additional requirements: None. - Document availability: For the duration of the work, at fabrication shop and on site.

130 GENERAL STEEL SECTIONS AND PLATES Generally • Standard: To BS EN 10025-2. • Grade: S355 Steel fabricator to determine sub-grade depending upon use and location. - Options: None. • Source: Obtain steel from a source accredited to a national or internationally accepted quality standard. • Other requirements: Test Certificates to be provided by steel fabricator.

135 HOLLOW STEEL SECTIONS Generally • Standard: To BS EN 10210-1. • Grade: S355 Steel fabricator to determine sub-grade depending upon use and location. - Options: None. • Source: Obtain steel from a source accredited to a national or internationally accepted quality standard. • Other requirements: Test Certificates to be provided by steel fabricator.

FRAME SYSTEMS

150A STEEL FRAMING SYSTEM • Manufacturer: Refer to Architect's Specification. - System reference: Submit proposals. • Element: Refer to Architects drawings • The specialist SFS fabricator/ contractor to allow for completing detail of all the framing system, the design and detail of the connections and be responsible for providing calculations and drawings for submission to Building Control for approval. The SFS system to the perimeter of the building is to provide resistance to wind loads and provide lateral restraint to the external masonry.

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COLD FORMED MATERIALS

176A PROFILED SHEET FOR ROOF AREA • Nature of permanent supports: Steel • Manufacturer: Subcontractor design element - submit proposals. - Product reference: Submit proposals. • Material: Galvanized steel sheet to BS EN 10326. - Thickness: As required . - Designation: Submit proposals. • Metal accessories: Provided by sheet manufacturer unless otherwise indicated: - Edge trims and restraint straps; - Side closure pieces; - End closures; and - End diaphragms. - Finish: As for sheet. • Seam stitching: - Fixings/ centres: As required to provide diaphragm action. Coating applied by manufacturer: Galvanized.

176B PROFILED SHEET FOR SHUTTERING/ COMPOSITE FLOOR SLABS • Nature of permanent supports: Decking to be designed so that propping is not required. • Manufacturer: Kingspan. - Product reference: Multideck 60 - V2. • Material: Galvanized steel sheet to BS EN 10326. - Thickness: 1.2 mm. - Designation: S350GD+Z275 N-A-C. • Metal accessories: Provided by sheet manufacturer unless otherwise indicated: - Edge trims and restraint straps; - Side closure pieces; and - End closures. - Finish: As for sheet. • Seam stitching: - Fixings/ centres: As per manufacturers recommendation. - Coating applied by manufacturer: Galvanized. Paint finish: Areas of decking over the swimming pools and wet change areas to receive a protective paint coating, suitable for the environment (C4). Refer to the Architects specification for details of paint finish.

FABRICATION

180 NOTIFICATION OF COMMENCEMENT • Notice: Give notice before fabrication is due to start. - Period of notice (minimum): Five working days .

183A WORKMANSHIP • Sheared or cropped edges: Dress to a neat workmanlike finish and free from distortion where parts are to be in metal to metal contact. • Defective work: At your own expense rectify to approval or replace.

190 MARKING • Identifying and recording materials and components: Submit details of proposed methods. • Location of marks: - Generally: Visible for checking after erection. - Weathering steel: On surfaces not exposed to open view in the completed work. • Steel to be blast cleaned, pickled, metal sprayed or galvanized: Marked so that subsequent treatment cannot obliterate the marking.

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195 HARD STAMPING • Usage: Not permitted except as indicated on drawings.

200 FAYING SURFACES FOR FRICTION GRIP CONNECTIONS • Location: As required. • Steel 25 mm thick or over: Check faying surfaces for deformities that may reduce slip factor to below design limit. - Remedial measures: Submit proposals. • Preparation/ treatment: Steelwork Fabricator's choice.

215 HOLLOW SECTIONS • Insides of sections: Debris and moisture removed before sealing ends and openings.

220 ACCESS/ VENTILATION HOLES IN BASE PLATES • Base plates larger than 1 m²: Make 25 mm diameter holes as necessary for pressure grouting, escape of entrapped air or direct compaction of filling/ bedding material.

225 STEELWORK TO BE GALVANIZED • Cutting, drilling and shop welding: Complete before galvanizing. • Vent and drain holes: Provide as necessary. - Locations: Submit proposals. - Sealing: Required, steel fabricator to submit proposals .

235A SHOP INSPECTION • Give notice: Before fabricating steelwork generally. - Period of notice (minimum): Five working days - Fabrication programme: Fabricator to provide to Kier Structural Engineer for reference.

WELDING

251A GENERAL REQUIREMENTS • Welding generally: In accordance with BS EN 1011. • Welded connections exposed to the elements in the completed structure: Continuously seam welded.

252A WELDING PROCEDURE • General: Reduce distortion to a minimum and adopt pre-setting if necessary. Take all necessary precautions to avoid built in stresses. • Workshops: Carry out welding in workshops or under similar controlled conditions. Allow inspection of material and assemblies before commencement of welding. • Supervisor: Carry out welding under the direction of an experienced and competent supervisor. • Major welds: Keep records of all major welds as required to ensure that all test results and welding operators responsible for the work can be identified. Hard stamping of finished work for this purpose: Not permitted. • Flame cutting type S355 material: Dressing of flame cut edges to be in accordance with NSSS, subject to demonstration of procedures to limit hardening effects to acceptable levels. • Cold worked steel 20 mm or more thick, welds in components which will be subject to tensile stresses and any other critical welds: Stress relieve or demonstrate procedures to limit hardening effects to acceptable levels.

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253A APPROVAL OF WELDING PROCEDURE • General: Prior to commencing fabrication submit for approval certification of weld procedure qualifications of any welders to be used, together with details of welding methods and procedures to be used and of testing procedures to be carried out. • Correct welding: Take responsibility for correct welding and for minimising distortion in the finished structure.

255A SITE WELDING • Usage: Notwithstanding clause 8.7 of the National Structural Steelwork Specification, permitted only where approved. If approved submit certification of weld procedures and qualifications of welders to be used on site at least five working days prior to start of the works. • Working conditions: Suitable and safe. Do not weld when surfaces are wet or when ambient temperature is below 0°C. • Testing: Test 100% of site welds unless directed otherwise.

256A FACE PREPARATION • Weld preparation: In accordance with BS EN 1011. • Fusion faces, angle of bevel, root radius, etc: Prepare properly to give the approved weld forms.

257A ASSEMBLY FOR WELDING • Parts to be welded: Assemble such that they are easily accessible and visible to the operator. • Fusion faces: Carefully align and maintain correct gap and alignment during welding. • Butt joints: Align root faces to within 2 mm. • Fillet welds: Keep edges and surfaces to be joined in as close contact as possible. Gap not to exceed 2 mm.

258A PREHEATING • General: Adhere to the recommendations of BS EN 1011. Do not weld mild steel when the ambient or plate temperature is 0°C or below. Where the combined plate thickness is equal to 50 mm or over, and the ambient or plate temperature is under 10°C, only weld where approved special precautions are taken to prevent too rapid a rate of cooling and heat loss. • Wet surfaces or where ambient temperature is 0°C or less: Heat sections to be welded until they are warm to the touch for a distance of not less than 75 mm on either side of the joint.

259A WELDING OF STRUCTURAL HOLLOW SECTIONS • General: Weld hollow members continuously and keep interior of members clean, dry and free from loose scale, etc. Provide vent holes where the structure, or part of a structure, is to be hot dip galvanised after fabrication. Plug these holes after galvanising. Close all openings, internally unpainted tubes or other elements with a suitable continuous welded cover plate or other approved means. • Structural hollow sections with a wall thickness of less than 4 mm: Provide special close tolerance fit-ups. Submit proposals for approval prior to commencement of any works. • Welds at end plates and flush surfaces: Grind flush.

260A BUTT WELDING • General: Full strength butt weld (FSBW) implies a full penetration, full strength weld; except on tubes, weld from both sides. Gouge out the back of the first run.

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265A ELECTRODES • Welding between different grades of steel: Use electrode relating to the higher yield stress material. • Protection: Store in bundles in dry conditions. Protect from adverse weather and damage.

270A ADDITIONAL WELDS • Welds (including tack welds) not indicated on drawings: Not permitted, even for temporary attachment or repair of faulty plates, without approval.

BOLT ASSEMBLIES

300A GENERAL REQUIREMENTS • Connected parts: Draw together firmly where necessary. Provide steel packing plates where necessary to ensure that the total remaining gap between adjacent surfaces does not exceed 2 mm. • Nuts and splice plates: Fix internal to column and beam flanges unless directed otherwise. Locate splices as dimensioned on the Engineer's drawings unless otherwise approved. • Washers: Provide at least one washer under the element of the bolt to be tightened. Additional requirements for washers: As specified on Engineer's drawings. • Nuts used on connections subject to vibration: Secure to prevent loosening. Use self locking nuts, an approved chemical product or locknuts. Ensure joints are free to move where slotted holes are provided for movement connections.

302 NON-PRELOADED BOLT ASSEMBLIES • Designation: Contractor's Choice. - Threading: Full length. • Nuts and washers: To suit grade of bolt, as NSSS, clause 2.3. • Coating applied by manufacturer: Contractor's Choice. • Other requirements: None.

303 PRELOADED BOLT ASSEMBLIES • Designation: BS EN 14399-3, strength class 8.8, system HR. • Coating applied by manufacturer: Contractor's Choice.

304A PROPRIETARY BOLT ASSEMBLIES AT POSITIONS OF THERMAL BRIDGING • Manufacturer: Schöck or similar approved. - Product reference: Isokorb Type KST.

304B PROPRIETARY BOLT ASSEMBLIES FOR HOLLOW SECTIONS • Manufacturer: Corus or similar approved. - Product reference: Hollo-Bolt .

310A ANCHORAGES TO CONCRETE • Design standard: To ETAG 001, Annex C. • Anchor type: Bonded anchor . • Material: Carbon steel. - Coating applied by manufacturer: Galvanized. • Concrete: - Grade: As Section E10. - Condition: Determined by relevant connection location. • Characteristic resistances of single anchor remote from edge of concrete (minimum): - Tension: See manufacturers information. - Shear: See manufacturers information. • Fixing in concrete: Bonded into predrilled hole using chemical bonding agent.

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312A HOLDING DOWN BOLT ASSEMBLIES • Design: Be responsible for completing the holding down bolt design in accordance with BS5950. Refer to specification work section E10 for details of concrete grade.

316A FINISH TO BOLT ASSEMBLIES • All bolts, nuts and washers : Spun galvanised, zinc plated, sherardized or as otherwise approved. • Compatibility: Confirm in writing that the finish is compatible with the steel finish and the environment.

325 DIRECT TENSION INDICATORS • Standard: To BS EN 14399-9. • Manufacturer: Contractor's choice. - Product reference: Contractor's choice. • Grade: Appropriate for grade of bolt and nut assembly. • Finish: Contractor's choice . • Ancillary components: Washers to BS EN 14399. • Post installation and inspection treatment: Where no further protective coating is specified, apply a butyl rubber sealing compound to seal measuring gap around indicators.

331A HIGH STRENGTH FRICTION GRIP FASTENERS • Fasteners complying with BS 4395: Use in accordance with BS 4604. • Friction grip connections where surfaces are not parallel: Provide a suitably tapered washer under the rotated head or nut. Use such washers under the non-rotated component except where the angle between bolt axis and contact surface is within the limits of 87° and 93°. • Where the use of other types of pre-tensioned friction grip fasteners is permitted: Install in accordance with manufacturer's recommendations and tighten to at least the minimum shank tensions specified in BS 4604. • Total remaining gap between adjacent surfaces in high strength friction grip bolted joints: Shall not exceed 1 mm.

332A TENSION CONTROL BOLTS • Where provided in lieu of high strength friction grip bolts: Use in accordance with the recommendations of SCI Publication P324, and comply with the suppliers reference standard JSS ll 09 S10T.

335 SPRING WASHERS • Standard: To BS 4464.

370 GALVANIZED COATING TO BOLT ASSEMBLIES • Standard: To BS 7371-6. • Galvanizing: Applied by fastener manufacturer. Passivated and lubricated if no additional coatings are specified. Nuts tapped after galvanizing. • Use/location: All shop and site connections in shop painted steelwork.

390 SEALED HOLLOW SECTIONS • Holes: Sealed to prevent access of moisture. Method of sealing: Steelwork Fabricator to submit proposals.

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ERECTION

401A ERECTION GENERALLY • General: Unless otherwise noted in this specification, the steelwork erection shall generally be in accordance with the National Structural Steelwork Specification (NSSS). Draw to the Engineer's attention any potential conflict between the two.

405 OUTLINE METHOD OF ERECTION • To be reviewed with steelwork fabricator and Willmott Dixon prior to start on site.

410 PRE-ERECTION CHECKS • Scope: At least 7 days before proposed erection start date, check the following: - Foundations and other structures to which steelwork will be attached: Accuracy of setting out. - Holding down bolts: Position, protruding length, slackness and condition. • Inaccuracies and defects: Report without delay. • Permission to commence erection: Obtain.

420A SETTING OUT • Positioning and levelling the steelwork: Take responsibility. • Permissible deviations: In addition to the requirements of BS5950, EC3 and the National Structural Steelwork Specification, comply with the following: - The level of the underside of a column base plate is not to deviate from the specified level by more than 5 mm. - The space beneath a base plate is to be not less than 25 mm and not more than 40 mm. - The deviation of a column at any level is not to exceed the greater of 5 mm or 1/600 of the column height over the actual position of the column at ground floor level. - Members other than columns are not to deviate from their specified position on plan relative to the columns to which they are connected by more than 5 mm. - The level of the top of the steelwork at any level is to be within 10 mm of the specified level. - The difference in levels between two or more beams meeting at a column is to be less than 5 mm, unless noted otherwise on the drawings. - Gaps in joints that depend on contact bearing after alignment are not to exceed 1 mm. - The maximum permitted deviation from a square as measured from a point 500 mm from any corner shall be ± 1.5°.

425 MODIFICATIONS • Steelwork: Do not modify without approval. • Temporary fabrication/ erection attachments: May remain when they will not interfere with subsequent work, and will be completely hidden by finishes; otherwise, remove

426A MARKING FOR ERECTION • Each structural element: Clearly mark to show its position and orientation in the structure upon reference to the erection drawings. Mark in contrasting coloured paint or similar weather-proof media. • Steel with special surface finishes: Mark so as not to damage or deface this finish.

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427A DELIVERY, STORAGE AND HANDLING • Fabricated parts: Handle and stack in such a way that permanent damage is not caused to the components. Minimise damage to the protective treatment on the steelwork. • Damage in transit: Protect all work. Take particular care to stiffen free ends, prevent permanent distortion and adequately protect all machined surfaces. Pack suitably and identify all bolts, nuts, washers, screws, small plates and articles. • Components: Do not allow to swing freely. Use man-made fibre ropes, webbing or chains with clean, undamaged heavy rubber sheathing to hold and guide the lift into place.

428A ERECTION EQUIPMENT • General: Adequate for the use for which it is put to on site and shall not cause damage or permanent deformation to the structure. • Non compliant equipment: Remove from site.

432A TEMPORARY SUPPORT • General: Take responsibility for the stability, adequacy, accuracy and correct assembly of the structure during all stages of erection. • Elements to be supported: Structural steel frame generally, until diaphragm roof deck in place. • Bracing/Restraints: Provide as necessary until permanent connection can be made to both the vertical and horizontal planes of the frame for the overall lateral stability. Give particular attention and allow adequate consideration for the temporary condition prior to completion of the installation of the composite floor decking which provides diaphragm action in the permanent condition. • Forces and moments in elements: Make an independent assessment until the connections are made.

440A COLUMN BASES • Final design and sizing: Take responsibility for the final design and sizing of column base plates in accordance with BS5950/EC3. • Levels: Adjust using steel shims or folding wedges no larger than necessary. • Location of shims/ wedges: Position symmetrically around perimeter of base plate. Do not use a single central pack. • Give notice: If space beneath any column base is outside specified limits for bedding thickness. • Accuracy of erection: Check, and correct errors before filling and bedding beneath bases and carrying out other adjacent work.

443 PROPRIETARY FILLING/ BEDDING OF COLUMN BASES Bedding thickness range: 25-40mm. • Preparation: Concrete surfaces scarified to provide a good mechanical key. • Bolt pockets and spaces beneath base plates: Completely filled with proprietary high strength non shrink grout.

446A SITE CONNECTIONS - GENERAL • General: Make connections as shown on Steelwork Contractor's erection drawings previously submitted. • Drifting with properly formed tape or barrel drifts: Permitted providing the force used does not cause elongation of the bolt holes. • Bolting including high strength friction grip bolting: Adhere to the requirements of clauses G10/300A, and G10/331A. • Bolt fixing: Fix with head, nut and washer(s) suitably shaped and, where indicated, with heads pointing in the direction shown on the drawings. Fix as clause G10/300A where not shown on the drawings. • Placing bolts in holes: Do not use force. Driving of bolts into holes is not permitted.

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447 BONDED ANCHORS • Holes: Clean and free from dust at time of installing anchor. • Permeable sleeves: Use in conditions where otherwise the loss of bonding agent would be unacceptably high. • Other requirements: None.

448A SITE CONNECTIONS - HIGH STRENGTH FRICTION GRIP BOLTS • General: Submit details of type of bolt and the manufacturer for approval. • Storage: Store bolts, nuts and washers so that they will not deteriorate. • Surfaces prior to contact: Free of any applied finish, deleterious matter or any other defect which would prevent solid seating of the parts, or would interfere with the development of friction between them.

449A SITE CONNECTIONS - WELDING • General: Not permitted without approval unless specifically detailed on the drawings. • Method: Metal-arc with suitable covered electrodes for all positions. Provide welding current from independent motor generators of adequate capacity. Provide suitable enclosures to guard against any effects from adverse weather. • Gas cutting or gas welding equipment: Not allowed without permission.

TESTING

460A INSPECTION • Access: Allow CA and/or an independent inspection authority access at any reasonable time to workshops, and those of any suppliers, to enable inspection of the work during fabrication. Provide all facilities, hand tools, lighting, etc. • Materials and fixings: Take responsibility for ensuring soundness and quality. • Commencement of fabrication: Give notice. • Completion of fabrication: Give 14 days notice to allow, if necessary, inspections or tests to be carried out prior to despatch of steelwork to site. • Welds uneven in size or oversized: Make good at own expense.

465A TESTING • In-house quality control: Carry out to prove and maintain the quality of the fabrication to approval. • Independent testing consultant: If required, nominate consultant to monitor the quality control of all work carried out. Pay all charges. • Pre-fabrication meeting: Attend with the testing consultant to determine the acceptability of in-house testing and the details of welder approvals and welding procedures required together with other relevant matters. • Tests not provided for in this specification: If required, meet all costs if materials or construction are not in accordance with the specification. • Test and examination results: Submit 2 copies immediately they are available.

466A NON-DESTRUCTIVE TESTING • Radiographic testing: Performed by an approved independent testing station on any site welds chosen by CA. • Welds containing any form of crack, lack of penetration or lack of fusion: Unacceptable. • Defective areas of weld: Cut out and reweld in an approved manner. • Repaired welds: Reinspected using the same technique as previously adopted. No further repairs allowed to a rewelded area.

468A TESTING The weld acceptance criteria to be adopted and the amount of non-destructive weld testing required will be in accordance with the NSSS or BS EN ISO 5817.

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470 SITE TESTING OF ANCHORS TO MASONRY • Standard: To BS 5080. • Preliminary tests: 3 No. tests for tensile loading to failure in locations that will be hidden in completed structure. • Proof tests: Test 50% of working fixings to 0.75 times the working load. • Test results: Report failures and seek instructions.

475 PRODUCTS • Steel: Submit test certificates.

480A DEFECTIVE WORK • General: Submit proposals for further testing, inspection or replacement of any part of the work or any materials known or suspected of being defective as soon as possible.

481A LOAD TESTS • General: Carry out and bear the cost of any load testing required on any part of the structure.

PROTECTIVE COATINGS

500A GENERAL REQUIREMENTS • General: Follow the recommendations of BS EN ISO 12944 in the interpretation of this specification and the execution of the work. • Refer to Architect's specification for all protective top coats and intumescent coatings to steel.

510A SURFACES NOT TO BE COATED • Any surface within 150 mm of areas to be site welded. • The contact surfaces of High Strength Friction Grip bolted connections. • Top flange surfaces of beams where site welding of studs is permitted.

515A OPERATIVES • General: Must be appropriately skilled and experienced in the use of specified materials and methods of application.

520A COATING MATERIALS • Manufacturing batches: Use from one batch wherever possible. Where more than one batch is to be used, keep separate, allocate to distinct parts or areas of the work and give notice. • Manufacturers recommendations: Check all coating materials are recommended by their manufacturers for the particular surface and exposure conditions and are compatible with each other.

522A STORAGE • General: Store the coating materials in accordance with manufacturer's instructions.

523A COMPATIBILITY OF SHOP PRIMER WITH SITE APPLIED INTUMESCENT COATING • Intumescent coating: Refer to Architect's specification. • Primer: Compatible with coating under general and fire conditions. • Manufacturer's recommendations and test evidence: Submit before priming. Include fire test data to BS 476-20 and -21, or BS EN 1363-1 and BS EN 1365-2, -3, and/or -4 as appropriate.

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527A MAINTENANCE PROCEDURE • General: Arrange for the protective coating manufacturer to confirm the maintenance procedure for the outer decorative paint finishes for the internal and external exposed areas, and to provide, on request, a written maintenance specification for adoption at the end of the anticipated life expectancy period.

530A GALVANISING • Steel to be galvanised: Hot dip galvanise to BS ISO 1461. Include all screws, bolts, nuts, washers, etc. • Timing: Subsequent to fabrication and welding unless approved by the Contractor's representative. Where permission is granted for subsequent fabrication and welding, cold galvanise the affected area to approval. • Repairs: Repair by cold galvanising all damaged elements to approval. Include the complete removal of all deleterious material including slag, scale, oil, paint, etc. from the weld and/or area of breakdown of protection. Prepare the surface to ensure that the local protection is of a comparable standard to the general protection. • Structural hollow sections: Provide adequate ventilation holes. After galvanising plug holes in an approved manner.

535A INSPECTION OF COATING WORK • Work in progress: Permit coating manufacturer to inspect and take samples of products. Do not comply with any directions or requests from the coating manufacturer's representative until confirmed by the CA. • Notice: Give notice of dates for: - Start of surface preparation and coating. - Coated members or components leaving the works. - Period of notice (minimum): 7 working days. • Samples for testing: Allow the CA to take samples from sealed containers, spray gun containers or from workman's kettles. Unopened sealed containers may be required to be set aside for subsequent tests.

540A HANDLING AND STORING COATED STEELWORK • General: Use methods and equipment which will minimise chafing, chipping and other damage. • Drying/ Curing: Ensure an adequate period for each coat before handling. • Handling: Use suitable packings, lashings, lifting harnesses, nylon slings, rubber protected chains and chocks, etc. • Protection during transportation: Stack clear of all surfaces and separated by timber chocks. Protect from possible adverse effects of ponded water. Exercise extreme care and attention to ensure the finished surface remains undamaged where the finish coat is shop applied. Make allowance for bubble wrap protection or similar. • Protection on site: Stack for storage clear of the ground, separated by timber chocks so that ponding does not occur.

545A PROTECTION • Freshly applied surface coatings: Adequately protect from damage. • Signs and barriers: Exhibit 'Wet Paint' signs and provide protective barriers where necessary. • Adjacent surfaces to those being covered: Adequately protect. • Surfaces to be painted: Ensure they are dry, clean and free from any dirt, oil, grease or other contamination.

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550 POST-GALVANIZING INSPECTION • Inspector: Submit, on request, evidence of training and competence in visual inspection for liquid metal assisted cracking. • Components for which visual inspection is not required (procedure PGI-0): Not applicable. • Components requiring additional inspection: - Procedure PGI-2A: None. - Procedure PGI-2B: None. • Timing: Before erection of steelwork or application of other coatings. • Action in event of non compliance: - Submit: Full records of all post-galvanising inspections, drawing attention to any erected components that are required to be quarantined. - Procedure PGI-3: Carry out on all quarantined components, and submit report. - Sites of suspected defects: Remove zinc coating by grinding back to bright metal for a distance of not less than 50 mm around each defect and from a similar area on opposite face of member and inspect. Remedial actions: Submit proposals.

551A REMEDIAL WORK • Unsatisfactory tested material: Re-execute any work coated with that material. • Unsatisfactory application or dry film thickness: Re-execute. Inadequate dry film thickness or surface defects due to inclement weather may be remedied by rubbing down and applying further coats as instructed, depending on the type of surface coating. • Early degradation of coatings by blistering, peeling, flaking, cracking, lack of adhesion, etc.: Make good by complete removal, preparation and reapplication of all coats as instructed. • Mechanical damage to coatings: Make good by local cutting back to bare bright steel, preparation and reapplication of all coats to leave a neat, continuous and flat finish. • Exposed bare metal: Clean thoroughly and prime within two hours. • Extensively damaged work: Return to the workshop, blast clean the affected area and reapply the protective coating..

560A CONTROL SAMPLES • Exposed steelwork requiring a decorative finish: Arrange for a sample flat plate (approx 500 mm square) or, by agreement, a suitable piece of steel to be coated in accordance with the specification in advance of the main works. • Following approval: Keep this sample at works and use as a reference to establish consistency of the finished work.

PROTECTIVE COATING SYSTEMS

620 GALVANIZING TO BLAST CLEANED STEEL • Use/ location: Refer to Architect's drawings and specification. • Preparation: Blast cleaning to BS EN ISO 8501-1, preparation grade Sa2½ using chilled angular iron grit grade G24 to give a coarse surface profile, followed by chemical cleaning. • Galvanizing: To BS EN ISO 1461. Minimum mean coating thickness: 140 micrometres.

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638 SHOP PRIMING FORInternal structural steelwork • Use/ location: Internally. • Shop preparation: - Generally: Blast cleaning to BS EN ISO 8501-1, preparation grade Sa 2½ and a surface profile mean peak to valley height of 70 to 100 microns. - Welds/ edges/ areas with surface imperfections: To BS EN ISO 8501-3, preparation grade P1. • Primer: Epoxy zinc phosphate primer. - Manufacturer: Sherwin Williams or similar approved. Product reference: Epigrip C400V3 or similar approved. - Dry film thickness: 75 microns. • Special requirements: Stripe intermediate coat to external angles. Colour of Epoxy blast primer to Architect's details.

650 SITE PAINTING WITHHIGH BUILD BITUMEN • Use/ location: Steelwork in cavities or below ground. • Paint manufacturer: Submit proposals. • Site preparation: Manual. • Site primer: As Clause 638. - Dry film thickness: As manufacturer's recommendations . • Site intermediate coat: As Architect's specification. - Dry film thickness: As Architect's specification . • Site top coat: As Architect's specification. - Dry film thickness: As Architect's specification . - Colour: As Architect's specification. • Special requirements: Stripe intermediate coat to external angles .

660A SHOP PLUS SITE PAINTING WITHINTUMESCENT COATING SYSTEM • Use/ location: Refer to Architect for locations. • Paint manufacturer: Sherwin Williams or similar approved. • Shop preparation: - Generally: Blast clean to BS EN ISO 8501-1, preparation grade Sa 2½ and a surface profile mean peak to valley height of 70 to 100 microns. - Welds/ edges/ areas with surface imperfections: To BS EN ISO 8501-3, preparation grade P1. • Shop primer: As G10/638. - Dry film thickness: 80 micron. • Shop intermediate coat: To be compatible with shop primer. - Dry film thickness: As recommended by paint manufacturer for the specified period of fire resistance and section factor of the steel member. • Top coat: To be compatible with intermediate coat. - Dry film thickness: As recommended by paint manufacturer. - Colour: To Architect's details. • Special requirements: Stripe intermediate coat to external angles.

PREPARATION FOR PAINTING

700A GENERAL REQUIREMENTS • Terminology: The term 'clean' means to be free from any matter which would contaminate the subsequent paint film and thus affect the life and durability of the coating.

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710 OFFSITE PREPARATION AND PAINTING • Working area: Covered and properly lit, heated and ventilated. • Sequence of working: Select from the following and submit proposals: - Fabricate, blast clean, prime. - Blast clean, fabricate, remove flash rust with a light overall sweep blast, prime. - Blast clean, apply weldable prefabrication primer, fabricate, prime. • Prefabrication primer (option 3): Type recommended by manufacturer of post fabrication primer. - Thickness of post fabrication primer coat: May be reduced if and as recommended by manufacturer. • Surfaces inaccessible after assembly: Apply full treatment and coating system including, if necessary, local application of site coatings.

720A BLAST CLEANING FOR PAINTING • Rust grades: Ensure that steel complies with BS 7079:Part 1 at time of blasting as follows: - Dry blasting: Initial rust grade A or B. - Wet blasting: Initial rust grade A, B or C. • Preparation: Thoroughly degrease. Remove millscale by chipping, grinding and/or heat treatment. • Blast clean: To the specified BS 7079:Part A1 preparation grades. Control quality of preparation in accordance with BS 5493, Appendix F. Use abrasive of suitable type and size, free from contamination by fines, water and oil. Remove abrasive residues. • Surface defects: Remove all defects likely to be detrimental to the protective painting system including: - Defects in the steel, including cracks, surface laminations, shelling and deep pitting as required by BS EN 10025. - Defects resulting from fabrication, including fins at cuts, burrs, sharp edges and weld splatter. • Primer: Apply as soon as practicable and while the surface is still in a condition acceptable to the primer manufacturer.

730 PREPARATION FOR SITE WELDING OF SHOP PAINTED STEELWORK • Method: Select from the following: - Mask weld areas immediately after blast cleaning and before coating steelwork. If paint system comprises more than one coat, step each coat 30 mm back from edge of preceding coat and away from masked areas. Remove masking immediately before welding. - Prepare and paint steelwork including weld areas. Grind off to bare steel around each weld area immediately before welding.

735 TREATMENT OF SITE WELDED JOINTS IN PAINTED STEELWORK • Preparation: After welding, and without delay, remove scale and weld spatter from weld areas. Remove traces of rust. Wash with clean water and allow to dry. Prime without delay. • Protective/ Decorative coatings: Apply to weld areas to match surrounding painted areas.

736 TREATMENT OF SITE WELDED JOINTS IN GALVANIZED STEELWORK • Preparation: After welding, and without delay, remove scale and weld spatter from weld areas. Remove traces of rust. Wash with clean water and allow to dry. • Coating: Reinstate using one of the methods given in BS EN ISO 1461, clause 6.3.

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740 BOLTED JOINTS (OTHER THAN FRICTION GRIP JOINTS) • Steelwork to be shop painted: Apply full shop specification to joint faces. • Steelwork to be erected with mill finish then site painted: Before erection, prepare and prime joint faces and allow to dry. • Bolted joints in externally exposed steelwork: - Immediately before assembling, apply a further coat of primer and bring surfaces together while still wet. - After assembling and before applying site coatings, seal crevices to bolts and joint perimeters with a compatible sealant.

745 FAYING SURFACES OF FRICTION GRIP JOINTS • Protection: Immediately after blast cleaning and before coating surrounding areas, mask faying surfaces to protect from contamination and deterioration. - Paint systems comprising more than one coat: Step each coat 30 mm back from edge of preceding coat and away from masked areas. • Removal of protection: Immediately before bolting, remove masking. Check faying surfaces are free from adhesive. Clean with solvent if necessary.

750 FRICTION GRIP JOINTS IN SHOP PAINTED STEELWORK • Post assembly treatment of bolts and surrounding areas: After final tightening of bolts and inspection of joints: - Thoroughly degrease and clean uncoated areas including bolts. - Prime without delay. - Apply full shop coating specification. • Direct tension indicators: Seal measuring gap to prevent ingress of moisture.

755 UNCOATED FASTENERS • Treatment: After steelwork erection and before applying site coatings, thoroughly degrease and clean. Without delay, coat to match adjacent shop painted areas.

760 GALVANIZED FASTENERS • Treatment: After steelwork erection and before applying site coatings, thoroughly degrease and clean. Etch prime.

765 SITE PREPARATION OF SHOP PAINTED STEELWORK • Preparation: Touch in shop coats, as necessary, and allow to dry. Before applying site coats (when specified), abrade surfaces or wash down or both, as recommended by paint manufacturer.

770 SITE PREPARATION OF GALVANIZED SURFACES FOR PAINTING • Preparation: Thoroughly degrease. Remove white corrosion products. Wash off and allow to dry before applying etching wash or primer.

PAINTING

800A GENERAL REQUIREMENTS Surface preparation or previously applied coating: Determine acceptability prior to application of specified coatings.

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805A FINISHES GENERALLY • Applied finish: Ensure that the finish does not in any way slump, flow, crack, flake, split, sag, pit, bubble, blister, float, effloresce, craze, shrink, break, wrinkle, crinkle, yellow, chalk, fade, discolour, powder, stain, bleed or lose its finish or gloss taking full account of the extremes of all atmospheric and environmental conditions specified for the service life. • Thinners: Do not add to paint to change its constitution or consistency in any way unless agreed by the protective coating manufacturer. • Finish required: Durable, resilient, of uniform texture, colour and appearance within the limits of the agreed samples and without irregularities or distortion. Ensure coatings match colour and gloss of agreed control samples. • Interval between successive coats: At least 24 hours or as recommended by protective coating manufacturer.

810A ENVIRONMENTAL CONDITIONS • General requirements prior to starting coating work: - Surfaces: Unaffected by moisture or frost. - Steel temperature: At least 3°C above dew point, with conditions stable or improving, and not high enough to cause blistering or wrinkling of the coating. - Relative humidity: Below 85%. " Precautions: Take all necessary precautions including restrictions on working hours, providing temporary protection, and allowing extra drying time to ensure that coatings are not adversely affected by climatic conditions before, during and after application. " Application of coatings: Taken as acceptance of the suitability and conditions within any given area..

815A COATINGS • Surfaces to be coated: Clean, dust free and suitably dry. Previous coats to be adequately cured. • Multiple coats of same material: Use different tints to assist checking of complete coverage. • Penultimate coat: Colour recommended by paint manufacturer to suit top coat colour. • Finish required: Smooth and even, of uniform thickness and colour, free from defects. • Dust and damage: Keep all surfaces free from dust during coating and drying. Adequately protect the completed work from damage. • Materials used in preparation: To be types recommended by their manufacturers and the coating manufacturer for the situation and the surfaces being prepared. • Manufacturing batches: Use from one batch wherever possible. Where more than one batch is to be used, keep separate, allocate to distinct parts or areas of the work and give notice. • Unsatisfactory work: Make good in accordance with clause G10/550 and to approval.

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820A FILM THICKNESS • Wet film thickness: During application, check thickness of each coat with a wheel or comb gauge used in accordance with BS EN ISO 2808. • Accumulated dry film thickness: After each coat has dried, check total accumulated film thickness. - Method: Magnetic or electromagnetic meter. - Number and position of measurements: As directed. - Validation: Measurements to be independently witnessed. - Meter calibration: Check against standard shims and recalibrate regularly against a smooth steel reference plate. • Average dry film thickness: - At least specified thickness over any square metre. - No reading to be less than 75% of specified thickness. • Accumulated dry film thickness deficiency: Apply additional coat(s) at your own expense if required. • Top coat dry film thickness: Sufficient to give an even, solid, opaque appearance.

825 STRIPE COAT • External angles, nuts, bolt heads, rough weld seams, and areas difficult to coat: Apply an additional stripe coat of undercoat and finishing coat .

850 JUNCTIONS WITH CONCRETE • Exposed steelwork partially embedded or encased in concrete: Apply two coats of bituminous coating locally to the steel/concrete junction. • Bituminous coating: To BS 6949, type 1, class A.

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