nbt pavatex pavaroof isolair board (pitched) - technical manual

7/22/2019 NBT Pavatex Pavaroof Isolair Board (Pitched) - Technical Manual

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Pitched Roof Solution

www.natural-building.co.uk T 01844 338 338F 01844 338 525



PAVAROOF pitchedTHE SCIENCE OF NATURE - THE FUTURE OF CONSTRUCTION

TECHNICAL MANUAL

subject to change without prior notice / 06.2007 / BB


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Natural Building Technologies LtdThe Hangar, Worminghall Road,

Oakley, Bucks HP18 9UL

Tel: +44 (0)1844 338 338Fax: +44 (0)1844 338 525

Email: [email protected]: www.natural-building.co.uk

Manual Content

Describtion of NBT Pitched RoofSolution

Performance GuideOverviewDecrement DelayThermal Bridges

Air Tightness

PAVAROOF pitchedSystem build upThermal PropertiesSpecification PavacladKey Consideration Designers &InstallersInstallation Procedures- Fitting Boards- Using Pavatape- Fixing Counter Battens

Technical Data Boards

Contact Address

Detail Drawings

3

4566

789

10

111213

15

15

16

2


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Describtion of NBT Pitched Roof Solutions

Made from 99.5% waste softwood and 0.5% inert water-proofing additives, Pavatex WoodfibreBoards (Pavatherm Plus, Isolair) are a genuinely sustainable non-toxic building material.To make Pavatex boards, waste wood fibres are pulped and mixed with water. The pulp is heated toactivate the lignin they contain in order to glue the fibres together. The pulp is then pressed intoboards, dried, and cut to size.The advanced manufacturing process uses the inherent properties ofwood fibres to produce boards with many excellent technical qualitiesfor thermal and acoustic insulation, thermal storage capacity, vapourpermeability and moisture control.

The NBT Roof Systems are...l Certified: LANTAC approval, BBA certification, BRE Green Guide

A rating, natureplus assessment and products are CE marked

l Cost effective

l Breathable

l Controls summer overheating

l Ecological

l Excellent acoustic performance

l No membrane required

l Simple and robust

l Especially suitable for rooms in roofs

The NBT Roof System is suitable for over rafter insulation. It provides a vapour permeable insulationand sarking layer that offers excellent thermal and acoustic performance without the need forwaterproof membrane.

3

ISO

IR

LA

SO

RI

I

LA

SIO

ISO

IR

LA

PAVAROOF pitched(with insulation between rafters and on top of rafters)


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Performance Guide Pitched Roof Solutions

...keeps the building warmer for longer in cold weather

When used on top of the rafters the boards reduce the effect ofthermal bridging and the interlocking board design easilyachieves good wind-tightness. All this increases thermalperformance.

A modern roof insulation system must do more than just protect building occupants from cold. It mustcreate a comfortable and healthy environment for the building users in all possible combinations ofexternal and internal conditions and control the effects of external heat, cold, noise and internalmoisture generation.

NBT pitched roof solution...

...keeps the building cooler in hot weather

The unique combination of high density, high specific heatcapacity and low thermal conductivity gives NBT roof solutions

the thermal mass required for overheating protection. Result is areduction of the max temperature under a roof of up to 4 degreescompared to a construction with similar u-value using lightweightinsulation products.

...keeps the building quieter

The high mass and the fibrous texture of Pavatex woodfibregives excellent acoustic performance. This allows you to achievegood roof constructions and internal environments even in areaswith high noise impact such as airports, railways and motorways.

...keeps the building dry and is breathablePavatex woodfibre boards are very vapour permeable andhygroscopic. For the roof products there is a latex impregnationthrough the whole board structure which offers continuedprotection to water penetration. The boards can withstand a threemonth exposure period without a roof covering. This gives doublesecurity in case a tile breaks and water penetrates this first roofcovering. No membrane on top of the latex impregnated

woodfibre board is required.

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Summer Overheating: Decrement Delay and Decrement Factor

As part of the design of the roof it is important to consider effects of summer overheating control,particulary when there are rooms in roofs or in buildings such as schools and halls where teachingspace exists directly below the roof. Summer overheating is in fact caused by any or a combinationof three reasons:

1) too large internal gains from appliances, people machines etc.2) two much sun directly through windows due to poor summer shading,3) heat passing directly through the roof.

The solution to the first is to reduce the gains or ventilate, the second to provide better shading, andthe third is to reduce peak heat gain to the room by changing the Decrement. Decrement can be

thought of as the amount a peak external surface temperature is smoothed out by the structure, andthe time that the peak is delayed before it reaches the inside.

These are in fact two factors and are called respectively Decrement factor and Decrement delay. Toreduce the solar heat from passing through a roof, we need a low decrement factor, and moreimportantly, have it occur a minimum of 6-12 hours after the midday external solar radiation peak iea decrement delay of at least 6-12 hours.In terms of achieving satisfactory values, an insulation material that also has thermal mass willproduce better values. What is required is a function of density, thermal conductivity and specificheat capacity. Pavatex woodfibre boards have an excellent combination of low k-value (0.038-0.047W/mK), high specific heat capacity (2100J/kgK) and for insulation boards a high density (140 240

kg/m) which far exceeds any conventional material. This means that with Pavatex woodfibreinsulation a lightweight structure such as timber can perform as though it was a mass structure.The consequence is the reduction of internal temperatures by 4degC or more in summer comparedto a roof with may have the same u-value but conventional insulation.

-

5

60

55

50

45

40

35

30

25

20

15

10

Temperature(de

gC)

06:00 09:00 12:00 15:00 18:00 21:00 00:00 03:00 06:00

August 18th 2005 August 19th 2005

Measured temperature under the red roof tiles

Measured temperature at the externalsurface of the ISOLAIR board

Temperature at the internal surface of the plasterboard (notconsidered effect of windows, internal heat sources and air

Tmaxexternal 26.2 degC

Tminexternal 13.6degC

Amplitude

ex

tern

Amplitude

intern

Decrement Delay


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Thermal Bridges

Advantage of additional insulation on top of the rafter

l less insulation between the rafter required for same u-value

l dimensions of rafters are just as big as they need to be for structural reason

l protection of structural rafters from external conditions and temperature changes

l less thermal bridges at all junctions because you have like a warm shell which goes on top of allsolid timber junctions

l better acoustic performance

l overheating protection in summer because of high thermal mass of PAVATHERM PLUS and

ISOLAIR woodfibre insulation

Air Tightness

With Building Regulations Part L: 2006 edition, a new figure gets more and more important forbuilding design. Air tightness of a structure is critical if it is to perform thermally and indeedacoustically. The limit for the design air permeability is 10m/(h.m) at 50Pa. Significantly betterstandards of air permeability are technically desirable in dwellings with mechanical ventilation,especially when using balanced systems with heat recovery.

NBT roof solutions allow you to achieve good air tightness in a easy and cost effective way. Themost difficult part is getting buildings air tight at junctions between building elements such as raftersand junctions with walls. Please find guidance for detailing in the last section of this technicalmanual.

Pavatherm Plus100mm

Pavatherm Plus60mm

Isolair 35mm Isolair 22mm BreatherMembrane

There are different ways to get a elemental u-vlaue of 0.20 W/mK*. As more you insulate on top ofthe rafters, as less is the effect of repeting and non-repeting thermal brides because of timber studs.

Insulation110mm

Rafter50/110

Insulation150mm

Rafter50/150

Insulation185mm

Rafter50/185

Insulation200mm

Rafter50/200

Insulation220mm

Rafter50/220

6

*all calculations including 8.3% thermal bridging because of timber rafters, insulation between rafters thermal conductivity0.039W/mK


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PAVAROOF pitched - Insulation between & on top of rafters

7

ISO

IR

LA

SO

R

I

LA

I

ISO

ISO

IR

LA

Tiles / Slate

Counter Battens

Tile Battens

ISOLAIR or PAVATHERMPLUS insulation

ISONAT (hemp/cotton),WARMCEL orSHEEPWOOL insulation

Air Tightness Layer &service void (optional)

Plasterboard and skim

PAVAROOF pitched


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System Build-Up PAVAROOF pitched

*based on ISONAT hemp/cotton(k=0.039 W/mK) with 8.3% bridging and no service void

Thermal Properties PAVAROOF pitched

8

Insulationonto StudInsulationbetween Rafter*U-Value[W/mK]DecrementFactorDecrementDelay [h]

Admittance[W/mK]

22mmIsolair100mmIsonat0.34

0.92

2.6

1.02


0.85

3.6

1.03


0.64

5.7

1.05

60mmPavatherm Pl.100mmIsonat0.26

0.72

4.9

1.05


0.57

6.4

1.06


0.44

7.7

1.06

1

2

Rafter Depth 100mm

1

2

Insulationonto StudInsulationbetween Rafter*U-Value[W/mK]DecrementFactorDecrementDelay [h]

Admittance[W/mK]


0.86

3.7

1.04


0.78

4.7

1.05


0.56

6.9

1.06


0.64

6.2

1.06


0.49

7.6

1.06


0.37

9.0

1.06

1

2

Rafter Depth 150mm

PAVAROOF pitched


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Specification PAVAROOF pitched

9

Isolair/ Pavatherm Plus boards of (specifythickness) thickness should be supported byat least two rafters spaced at a maximum of(specify distance) mm at all times.

Working from eaves to ridge lay PavatexIsolair/ Pavatherm Plus boards of (specifythickness) thickness over rafters in staggeredbond pattern with board tongue facing upslope and joints full engaged.

Temporarily secure board with one (specifymake) fixing part no: (specify part no:) perrafter.

Isolair boards should be cut using eitherPavatex knife edge jigsaw blades part noPAVZK, or by a wavy edge insulation knife orby circular saw with a fine toothed tungstencarbide tipped blade.

For roof pitches >20 boards are laid dry - noglueing required (see image).

For pitches of between 10 and 20 apply abead of Pavatex Isoroof glue part no PAVZGusing a Pavatex glue gun part no PAVZGG tothe upper face of each tongue before fittingnext board (see image).

For pitches 20 - laid dry (no gluing required)

10 to 20 - glued with Isolair glue

PAVAROOF pitched


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Key Considerations PAVAROOF pitched for Designer &Installer

10

General: interstitial condensation.The PAVAROOF system must be installedonly by competent contractors. The Ventilation batten space:contractors must be provided with full and Sufficient air movement between ISOLAIR/complete technical illustration details for all PAVATHERM PLUS and the roof covering isareas of the system. Leave nothing to be required because of the breathable build up ofagreed on site. Plan board layout prior to the roof system. In accordance to BS ENcommenting installation to reduce wastage. 5250, for air-open outer coverings no specific

provision for batten-space ventilation is

System Guarantee: required but for tight outer coverings battenThe system can only be guaranteed if boards space ventilation should be provided. I.e.and accessories approved by NBT are used. openings to the batten space which areUse only fixings as per NBTs equivalent to a continuous slot 25mm wide inrecommendations or manufacturers the eaves and 5mm wide at the ridge andinstructions. PAVAROOF pitched has LANTAC 25mm counterbattens.approval and BBA certification 07/4448.

Non Load Bearing:Weather Tightness: Be aware that ISOLAIR and PAVATHERMFor pitches over 20 boards are laid dry and PLUS boards are not load bearing. Only standno glueing of the boards is required. ISOLAIR on top of rafters during installation of theand PAVATHERM PLUS boards are boards.interlocking at all four sides providing weather

tightness. Latex impregnation through the Maximal Rafter Center Distanceboards structure offers continued protection,the boards can withstand a 3 month exposureperiod without roof covering whilst continuingto protect the building (provided that all tapingwork is properly done and counterbattens areinstalled). On top of ISOLAIR or PAVATHERMPLUS no breather membrane is required.Note: If the design of the roof includes lots ofvalleys and roof lights, using a breathermembrane can be a cost effective option.Please ask NBT technical department.

Air Tightness:

An additional layer is required to provide goodair tightness. NBT recommends to install aservice void with an additional air tightnesspaper if installations are running under thefinished internal surface. Alternatively you candesign the plasterboard & skim as the airtightness layer if a service void is notrequired. Carefully design the air tightnesslayer at all openings, junctions andpenetrations.

Vapour Control Layer:NBT systems are breathable build-ups and

theres no need to install an internal vapourbarrier. Your air tightness layer works asvapour control layer, there is no risk for

PAVAROOF pitched

Board

Isolair 22mm

Isolair 35mm

Isolair 60mm

max. rafter

centre distance

0.85 m

1.00 m

1.10 m

Board

Pavatherm Plus

60mm

Pavatherm Plus

80mm

Pavatherm Plus

100mm

max. rafter

centre distance0.79 m

0.79 m

0.79 m


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Fix first board with Locate end tongue The 35mm and by at least twotongue uppermost first then slide 60mm board can rafters and is fullyusing one fixing town onto lower sustain light foot fixed).per rafter (Final board. Fix with traffic betweenfixing occurs one fixing as step rafters (provided Stagger joints tothrough batten). one. great care is taken ensure that no

and centers are no vertical joint nextgreater than to each other fall600mm and the within same rafter

board is supported space.

Fitting

Damaged boards and butt edged jointsAny damaged areas and butt edged joints should be filled with Woodfibre offcuts - primed andtaped with Pavatex PAVATAPE to ensure the integrity of the layer and to prevent water ingress. (Seeusing PAVATAPE Section).

Openings and penetrationsAll openings and penetrations should be primed and taped with Pavatex PAVATAPE to ensure theintegrity of the layer and to prevent water ingress. (See using PAVATAPE section).

Expansion joints

Expansion joints must be provided for section of more than 15m long. After all the roof boards havebeen fitted cut a 5mm wide groove through the board on the center line of a rafter. Seal over thegroove with Pavatex PAVATAPE to form a sealed air gap (see using PAVATAPE section).

CuttingThe boards are easily cut with any of thefollowing tools:

Pavatex Knife edge jigsaw blade, bayonetfitting to suit most makes of jigsaw, part no:PAVZK.

Standard wave edge insulation knife.

Circular saw, hand-held or bench mountedwith a fine, cross-cut, tungsten tippedblade.

Safety goggles and dust mask must be wornduring cutting to protect the user from thesmall, non hazardous, dust particles.

Installation Procedures PAVAROOF pitchedStep 1 - Fitting Boards >> Step 2 - Using Pavatape >> Step 3 - Fixing Counter Batten

11

Pavatex Jig Saw Blades

PAVAROOF pitched


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Guidelines for use

Only use PAVATAPE on dry, clean and dust-free Pavatex board

Use after fitting boards and always BEFORE installing battens

Two priming solutions are available dependent on weather conditions: For temperaturesbetween 5 - 10 degC usePAVZTP05solvent based else use PAVZTP5water-based

Apply Pavatex PRIMER with a brush or roller onto the board and abutments and allow to dry:Water-based primer is temperature sensitive - drying time is between 30 and 60 minutes (@20degC ca 30min / @ 5 degC ca 60min). Drying time for solvent based is 20min.

PAVATAPE should not be applied if the temperature is below 5 degC - Contact NBT forGuidance.

Store Pavatex PAVATAPE rolls on a flat surface in a dry dust-free environment.

Shelf life when stored at around 20 degC is unlimited for PAVATAPE. PRIMER needs to be usedwithin 12 month after manufacture.

PAVATAPE is supplied on 15m rolls.

PAVZTP5Water-based Primer is supplied in 5 Litre tins (coverage 20m/l 6 Rolls PAVATAPE per tin).

PAVZTP05Solvent-based Primer is supplied in 0.5 Litre tins (coverage 30m/l 1 Roll PAVATAPE per tin).


How to use

When to use

Valleys Ridges Chimneys and wallabutments**

Vent Pipes** Rooflights**

PAVATAPE selfadhesive butyl tape15m long x 150mmwide.

Clean surface witha brush. SurfaceMUSTbe dry toensure adhesion.

Apply PRIMER witha brush or a rollerand allow to dry.

Roll out PAVATAPEand press downwith other hand.

Avoid creases.

Press PAVATAPEon firmly using ahard faceddecorators seamroller or similar.

12

4

2

31

15cm

53

1

2

15cm

A high quality breather membrane can be used over ridges instead of PAVATAPE if required - pleaseensure that the strop of membrane is placed centrally over the ridge to offer maximum weather

protection - is pulled tight and is firmly secured under the counter batten.Note: If have roof design with many rooflights and valleys, the use of breather membrane on top ofthe woodfibre might be an optional solution to simplify sealing work.

**for further advise ask NBT technical

PAVAROOF pitched


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Guidelines for use

Only use fixings as per NBTs recommendations or manufactures instructions

Batten / rail system should applied AFTER taping / sealing the area

Fix through the counter batten and ISOLAIR or PAVATHERM PLUS directly into the rafter

Finally fix batten and tiles with conventional roofingtechniques


13

ISOLAIR 22mml Nails: 3.8 x 100mm corrosion resistant with 30x50mm counter battens (pre drill holes if necessary

to avoid battens splitting)

l Helifix: 90mm InSkew 600 fixings with 25x50mm counter battens. Refer to Helifix enquiry sheetfor fixing centres and application limits.

l Screws: EJOT TKR 4.8 x 90mm with 25x50mm counter battens. Recommended embedment inthe timber is 40mm. Refer to EJOT for fixing centres and application limits.

Roof Covering

Lightweight


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Helifix Ltd EJOT U.K. Limited21 Warple Way Hurricane CloseLondon Sherburn Enterprise Park

W3 0RX Sherburn-in-ElmetEngland LeedsFreephone 0800 731 7732 LS25 6PBTel: 020 8735 5200 Tel: 01977 6870740Fax: 020 8735 5201 Fax: 01977 687041

Web: www.ejot.co.uk

PAVAROOF pitched

ISOLAIR 60mm / PAVATHERM PLUS 60mml Nails: 6.0 x 180mm corrosion resistant with 40x60mm counter battens (pre drill holes to avoid

battens splitting

l Helifix: 120mm InSkew 600 fixings with 25x50mm counter battens. Refer to Helifix enquiry sheetfor fixing centres and application limits.

l Screws: EJOT TKR 4.8 x 130mm with 25x50mm counter battens. Recommended embedment inthe timber is 40mm.

Roof Covering

Lightweight


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Title

Drawing Number

CAD File Name

Drawn By Date

Pavaroof pitched Eaves

PRP003 Beat 02.02.2007

PRP003 070202 Eaves

he Hangar, Worminghall Road,akley, Buckinghamshire.P18 9UL

el: 01844 338338ax: 01844 338525

Pavatex ISOLAIR orPAVATHERM PLUS

woodfibre insulation

Air Tightness Layer

Plasterboard

Counter Batten(Ventilation)

Tile Batten

NBT Natural Insulation (Warmcell,Isonat, Sheepwool) between Rafters

Service Void (optional)

Eaves Ventilation

Element (25mm)

PAVATAPE Butyltape Sealing


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Title

Drawing Number

CAD File Name

Drawn By Date

Pavaroof pitched VergeUK

PRP005 Beat 02.02.2007

PRP005 070202 VergeUK

he Hangar, Worminghall Road,akley, Buckinghamshire.P18 9UL

el: 01844 338338ax: 01844 338525

Pavatex ISOLAIR orPAVATHERM PLUS

woodfibre insulation

Air Tightness Layer

Plasterboard

Counter Batten

(Ventilation)

Tile Batten

NBT Natural Insulation (Warmcell,Isonat, Sheepwool) between Rafters

Compriband


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18/20


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Product Overview: Insulation

ISOLAIR L sarking board

PAVATEX wood fibre board for breathable

roof & wall constructions

Size: 770 x 2500 mm

Cover area: 750 x 2480 mm

Thicknesses: 22, 35 & 60 mm

k-value/ D: 0.047 W/(mK)

Density: 240 kg/m3

PAVATEX DIFFUTHERM external wall insulation

Wood fibre board for rendered external wall

insulation

Size: 790 x 1300 mm

Reveal board: 600 x 1200 mm



Density: 180 kg/m3

PAVATHERM-PLUS sarking board

Composite wood board for roof & wall

insulation

Size: 780 x 1580 mm



Density: 180 kg/m3

Compr. strenght: >70 kPa (at 10 % compression)

PAVADENTRO internal wall insulation

Innovative wood fibre insulation board for

refurbishment

Size: 600 x 1020 mm

Cover area: 590 x 1010 mm



Density: 180 kg/m3

PAVATHERM general purpose insulation board

Universal wood fibre board for use in

external & internal walls, floors & roofs

Sizes: 600 x 1020 &

1200 x 2050 mm

Thicknesses: 20 -100 mm

k-value /D: 0.038 W/(mK)

Density: 140 kg/m3

PAVABOARD load bearing insulation

Wood fibre board for highly insulated floors

that have to carry loads

Size: 600 x 1020 mm

Thicknesses: 40 & 60 mm


Density: 210 kg/m3

Compr. strenght: >150 kPa (at 10 % compression)

PAVATHERM-FLOOR-NK wall & floor board

Wood fibre board for insulating floors or

internal walls with plaster

Size: 600 x 1020 cm

Thicknesses: 40 & 60 mm

k-value /D: 0.044 W/(mK)

Density: 180 kg/m3

Compr. strenght: >70 kPa (at 10 % compr.ession)

PAVATEX accessories

NBT provides the full range of PAVATEX

accessories & complementary products:

PAVATAPE incl. waterbased/solvent primers

(for junctions on walls & roofs)

PAVATEX cutting blades & knives

PAVATEX system glue (for sarking boards)

etc.

NBT Hemp Batts

Flexible hemp insulation batts for loft, walls,

floors & ceilings

Size I: 385 x 1200 mm

Size II: 575 x 1200 mm

Thicknesses: 50, 75, 100 & 140*mm

k-value /D: 0.040 W/(mK)Density: 40 kg/m3 *only size II

NBT Warmcel 100 cellulose fibres

Loose fill derived from waste UK newsprint

treated with fire retardant and biocidal

additives

Packaging: Bags of 8 kg (compressed)

Cover area: e.g. 1 m2at 228 mm

k-value/ D: 0.035 W/(mK)Density: 35 kg/m3

ISOLAIR L, all PAVATHERM products, PAVATEX DIFFUTHERM & NBT Hemp Batts are cer tified by natureplus. This testifies to excellent natural & ecological compatability.

PAVATEX wood fibre insulation boards are manufactured in Switzerland according to BS EN 13171, have the CE marking and are monitored by 3rdparties.

NBT Hemp Batts are manufactured in Poland according to ETA-06/0040 Z-23.16-1598, have the CE marking & are monitored by 3rdparties.

NBT Warmcel 100 is manufactured in the UK according to prEN 15101 & has the CE marking.

The following applies to all PAVATEX products: Specific heat capacity c = 2100 kJ/(kgK), Euroclass E (according to BS EN 13501-1), vapour resistivity = 5 (25 MNs/gm)

The following applies to NBT Hemp Batts: Specific heat capacity c = 1700 kJ/(kgK), Euroclass D-s3,d0 (according to BS EN 13501-1), vapour resistivity = 2 (10 MNs/gm)

The following applies to NBT Warmcell 100: Specific heat capacity c = 1700 kJ/kgK), Euroclass E (according to BS EN 13501-1), vapour resistivity = 1.86 (9.3 MNs/gm)

oalterationdueto

developement

O

Natural Building Technologies Ltd.

The Hangar, Worminghall Road

Oakley, Bucks, HP18 9UL

Tel: +44 (0)1844 338338

F 44 (0)1844 338525

Your business development manager is happy to give

professional advice:

CERTIFICATE No 07/4448

nbt pavatex pavaroof isolair board (pitched) - technical manual

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