forensic building consultants ltd · po box 27254 mt roskill auckland 1440 nz t +64 9 636 3485 f...

__________________________________________________________________________________________________

Remediation Specialists ! Weathertight Assessments ! Project Management

Building Condition Surveys ! Expert Witness ! Quantity Surveying

Forensic Building

Consultants ltd

PO Box 27254 Mt Roskill Auckland 1440 NZ t +64 9 636 3485 f +64 9 636 3486

e [email protected]

Invasive Residential Weathertight Building Assessment

7A FAIRSEA PLACE, LYNFIELD

This report is CONFIDENTIAL to the person/s named in the Details section and may contain privileged material. It must not be used, disclosed or copied without the consent of the said

person/s. This report must not be used, disclosed or copied, except in full.

of 36. Residential Weathertight Building Assessment at 7a Fairsea Pl, Lynfield, Auckland Residential Weathertight Building Assessment at 7a Fairsea Pl, Lynfield, Auckland

November 2012

Forensic Building Consultants ltd

Table of Contents

1! Details ........................................................................................................................ 3!

2! Executive Summary ................................................................................................... 4!

3! Purpose of Report ...................................................................................................... 5!

4! Limitations and Exclusions From This Report ............................................................ 6!

5! Description of Dwelling .............................................................................................. 6!

6! Background to Report ................................................................................................ 8!

7! Investigative Methodology ......................................................................................... 9!

7.1! Equipment Used .................................................................................................. 9!

7.2! Methodology ........................................................................................................ 9!

7.3! Other Analysis ..................................................................................................... 9!

7.4! Invasive Moisture Meter Criteria ........................................................................ 10!

8! Results and Observations ........................................................................................ 10!

8.1! Non-invasive Visual Inspection of Exterior Envelope ........................................ 10!

9! Conclusion ............................................................................................................... 26!

10! Recommendations ................................................................................................. 26!

11! Estimate of Cost to Repair ..................................................................................... 28!

12! Appendix 1: Understanding Weathertightness Principles ...................................... 34!

13! Appendix 2: Glossary ............................................................................................. 35!


November 2012


1 Details

Report prepared for (Client)

Geoff & Cathy Clow

7A Fairsea Place

Lynfield

Auckland 1042

M: 021627120

H: 09 627 1206

E: [email protected]

Inspection address 7A Fairsea Place, Lynfield, Auckland

Legal description Flat 2 DP 159291 on Lot 39 DP 75317

FBC Ltd reference no 2921

Information to client by

FBC Ltd

Introductory letter emailed 11.09.2012:

L-FBCServices-7aFairseaPl,Lynfield,11.9.12

Date of inspection 11.00 a.m., Tuesday 20 November 2012

Name/s of those

present at inspection

Craig Turner, FBC Ltd

Kim Wilson, FBC Ltd

Weather conditions Fine.

Information provided by or referred to by client

Original building consent drawings provided by client.


November 2012


2 Executive Summary

Forensic Building Consultants Ltd (FBC) was engaged by the owners to undertake an assessment of the weathertightness of the property and to provide guidance on extent of repairs at 7a Fairsea Place, Lynfield. Our investigation found that either indications of and/or water ingress is occurring, in particular to the following areas:

General

The Harditex cladding has not been installed in accordance with James Hardie’s Installation Manual June 1993. To all elevations, the following were evidently repeated on each elevation:

a. Excess moisture transferred in from the floor due to the TFC cladding finishing hard onto or below hard and soft landscaping.

b. Lack of sill and jamb flashings to all exterior joinery, allowing no path for the water to vent and drain from the head.

c. Fibre cement sheets have been incorrectly installed around openings, no control joints vertically or horizontally, and no clearance between the Texture over Fibre Cement (TFC) cladding and concrete floor slab.

Roof

There is a 2 level split roof with a flat roof and parapet system; the following was evident on both levels:

d. The timber framed parapet has been clad in Harditex fibre cement cladding with a painted textured plaster finish. High levels of moisture were evident.

e. The butyl rubber lined box gutters that run around the perimeter of the roof have been undersized, allowing water to be directed into and below the roof framing.

f. External rain heads and scupper outlets throughout the property were inadequately formed and poorly installed.

South Elevation

g. The concrete block wall for the pool where it is butted up against the external southwest corner. Cracks were evident in the plaster coating, allowing water to ingress into the fibre cement board and wall framing.

h. Front entry portico has fibre cement cladding with a painted texture finish. The top of the portico is a flat surface showing signs of water ingress.

West Elevation

i. Decking has been fixed up against the house with no drainage plane or flashings systems at the deck to house wall junction/s.

j. There is entrapment of the fibre cement cladding at the base of the deck balustrade.

k. The stainless steel handrail is fixed directly onto the flat top balustrade surface.


November 2012


North Elevation

l. The 2 storey wall has no inter-storey expansion joint.

m. Sheet cladding has been installed, such that it is in line with the window jambs.

For details of defects and non-compliances, refer section 8, Results & Observations.

Due to the extent of excess water ingress identified, the only successful and lawful option is to reclad the dwelling. We anticipate the extent of framing replacement for the most part to be:

i. To the perimeter floor joists, full stud and jack studs to majority of windows, particularly on the north and west walls.

ii. Complete wall framing to be replaced at wall of kitchen.

Due to the fall of the roof and the detail and size of the box gutters and parapet being inadequate, the best option is to completely remove the roof and parapet and replace with a trussed hip roof and an acceptable roof cladding and gutter system.

The proposed works will require a building consent.

Without the complete removal of external wall claddings, we cannot be definite about the extent of decay damage that may have occurred due to excess moisture ingress to the house wall frame.

3 Purpose of Report

The owner requested an independent, non-invasive inspection and moisture check of specific areas of the dwelling. This inspection was to better identify the locations and extent of excess moisture ingress into the dwelling, along with the potential locations and extent of decay damage to the light structural timber frame, to recommend to the owner a repair solution.

From the findings, FBC to make recommendations of the extent and scope of works required to rectify the dwelling; these recommendations will be forwarded to the contracted designer. FBC are of the understanding that the owners are proposing to do other alterations to the property that will add to this remedial work.


November 2012


4 Limitations and Exclusions From This Report

FBC was not involved in the original construction work. FBC does not accept any responsibility for the quality of any of the building work undertaken.

Similarly this report is not, nor does it purport to be the equivalent of a final inspection that might be undertaken by a Council or Building Consent Authority (BCA) or a Code Compliance Certificate that might be issued by the BCA.

FBC was engaged to assess the performance of the building work in terms of building code clauses B1, E2 and B2, as it relates to B1 and E2. The performance of the building work in relation to any other building code clause was not the subject of the inspection and is therefore not included in this report. Omission of an assessment of these other clauses does not imply that they comply with the building code performance standards.

5 Description of Dwelling

The dwelling is located on a steep sloping site in the suburb of Lynfield, where there is low density housing. The dwelling has a westerly facing aspect out to the Manukau Harbour with exposure to salt sea air and coastal conditions; surrounded by mature vegetation, with a number of radiata pines, therefore roof surface will be subject to pine needle deposits. The dwelling is located on a shared common drive with fall towards the north.

The dwelling comprises a split level two storey residential building. It is on a timber pile foundation with some reinforced concrete masonry foundation walls. Dwelling has light structural timber frame walls, mid-floor and roof framing. Major exterior cladding is Texture over Fibre Cement (TFC) sheet with face fixed powder coated aluminium window joinery. Dwelling has pan deck metal roofing and butyl rubber lined box gutters and parapets clad with TFC.


November 2012


Construction Risk Factors:

Complex roofs Yes

Parapets Yes

Eaves and soffits (width) Yes

Roof/wall junctions Yes

Deck/wall junctions Yes

Deck balustrade and handrails Yes

Doors and balconies No

Monolithic cladding Yes

Complex building junctions Yes

Exterior joinery flashings Yes

Penetrations (services, pergolas) Yes

Ground clearances Yes

• Dwelling is constructed with a cement based monolithic cladding system, direct fixed to the light structural timber frame, not with a cavity system to allow for drying and drainage; it relies on diffusion for the removal of moisture, should it be absorbed into the external envelope to exterior walls.

• Given its time of construction, dwelling will have boron treated timber framing to the majority of the construction, with H3.2 treated framing to the small number of areas where applicable. This type of structural timber framing has proven to be more durable and to have a greater resistance to decay when exposed to periodic wetting. However decay damages can still develop in treated timber framing if exposed to consistently high levels of moisture for consistent periods of time.


November 2012


E2/AS1 Building Envelope Risk Matrix

In accordance with the current 2011 E2/AS1 building envelope risk matrix, we assess the building to have a score of 14 (refer table below).

Risk Severity

Risk Factor low

sc

ore

medium

sc

ore

high

sc

ore

very

high

sc

ore

Subtotals for each risk factor

Wind zone

(per NZS 3604) 0 0 1 2 2 2

No. of storeys 0 1 1 2 4 1

Roof/wall intersection design 0 1 3 3 5 3

Eaves width 0 1 2 5 5 5

Envelope complexity 0 1 1 3 6 1

Deck design 0 2 2 4 6 2

Total Risk Score: 14

6 Background to Report

The property was built in 1992, with the owners having noticed over a period of time that there was water ingress through the parapet and internal gutters, particularly in the area of the kitchen. Small remedial work has been undertaken to prohibit and slow down any future water ingress.

The owners wish to undertake further alterations internally and additionally, by adding a further room above the main entry. This report is to identify the areas and extent of damage evident in the building so this can be incorporated into the new design.


November 2012


7 Investigative Methodology

7.1 Equipment Used

Moisture meters:

• A Delta 2400 non-invasive moisture meter (provides indicative readings only) has been used to test a sampling of areas.

• A Carrel & Carrel C901 invasive moisture meter with sliding hammer and 60mm probes, serial no. 73556/8 has been used to test a sampling of areas.

Other equipment:

• Digital level

• Multi-function pocket knife

• Electric/battery drill

• Extension folding and short ladders

• Digital camera

• Dictaphone

7.2 Methodology

• Undertake a visual non-invasive inspection of the exterior and interior of the building to identify at risk areas/defects of the dwelling or areas evidencing defects potentially due to excess moisture ingress.

• Check exterior envelope and the interior face of exterior wall linings for excess levels of moisture ingress with a non-invasive moisture meter.

• Identify potential areas of failure and/or defects that may be contributing factors to the areas of concern as raised by the owner.

As a result of findings during the inspection, further instruction and permission was given for the inspector to undertake a small number of invasive moisture tests to the west lounge wall facing the pool. The following additional procedure/s were undertaken:

• Drill through exterior wall linings to take moisture readings with a resistance moisture meter to provide accurate readings of moisture content to the light structural timber framing.

7.3 Other Analysis

No building materials or timber framing samples were taken for analysis undertaken by an independent laboratory.

of 36. Residential Weathertight Building Assessment at 7a Fairsea Pl, Lynfield, Auckland

November 2012


7.4 Invasive Moisture Meter Criteria

As a general guide, moisture content (MC) readings in Pinus Radiata timber framing should be considered according to the following criteria:

MC % Range Likely Effect/s / Evidence

8 – 14 Normal Not likely to support decay species.

15 – 19 Elevated Further investigation warranted; may allow the establishment of decay species, under certain conditions.

20 – 27 High

Will show signs of moisture ingress. Will allow the establishment of decay species. Damages at the higher end of this range are to be expected.

28+ Very High Of concern, is above fibre saturation point. High probability that decay is likely to develop.

8 Results and Observations

8.1 Non-invasive Visual Inspection of Exterior Envelope

Dwelling was inspected in an anti-clockwise direction, commencing at the southeast corner. For simplicity of description, we refer to the main entry facade as the south elevation.

We undertook a non-invasive inspection to the exterior elevations of the dwelling. Invasive moisture checks were undertaken at specifically nominated areas evidencing potential moisture ingress.

We undertook a non-invasive visual inspection to the interior, focusing on the north, south and west elevations.

• Other than two specific areas there were generally no undue visual signs to the interior finishes that implied any indication of damage as a result of excess moisture ingress to majority of wall linings.

• There were visual signs of damage to the living room linings, in particular where the exterior concrete block wall meets the dwelling on the northwest corner and the west wall lining showing damage at the skirting level. The kitchen wall linings had signs of damage from water ingressing from the roof above, including damage to the flooring.

• Damage to the wall framing was visible where gypsum wall linings were removed in the northwest corner of the master bedroom.

• Despite the general lack of visual indications of water ingress to the internal finishes, non-invasive moisture readings were indicatively high to most locations checked.


November 2012


8.1.1 General

To all elevations, we observed the following commonly repeated defects:

i. There were no sill or jamb flashings to any of the exterior joinery of the dwelling as required by James Hardie installation instructions.

ii. The TFC cladding was hard down onto both hard and soft landscaping.

iii. Non-invasive moisture readings to the bottom plate demonstrated high MC due to incorrect ground clearances. All of the bottom plate MC readings read either high or very high. This is of concern, as most of these indicative readings were above fibre saturation point, indicating a high probability that timber decay is likely or has already developed.

8.1.2 Roof

The entire roof is experiencing the following defects:

i. The pan deck metal roofing was measured with our Smart Digital level. The pitch measured between 2.2° and 1.7°, which is less than the minimum 3° required for this type of roofing.

No sill or jamb flashings to exterior windows.


November 2012


ii. The parapets have been clad in the TFC cladding, which runs down the inside face of the parapet hard down onto the roof flashings or the roof surfaces. Where there are box gutters there is a 25mm or less difference in height between the bottom of the gutter and the bottom edge of the cladding. This means the cladding has been subject to moisture uplift.

iii. Advanced lichen growth was evident on the flat top surfaces of the parapets and the internal face of the entire roof surface. Non-invasive moisture readings were indicatively in the high 30s or greater, on both the internal and external face of the parapet. There is high probability of extensive decay damage to these parapet walls to the entire perimeter of the dwelling.

iv. In the master bedroom, there has been noticeable decay damage of the wall framing and internal wall lining. Above this location there is no soffit. There is an internal boxed gutter and a rain head that runs over the head of the wall.

Indicative moisture reading of 35.3% to the parapet wall.

1.8° pitch shown on metal roof. Minimum required pitch is 3º.


November 2012


v. Visual inspection of all the scupper outlets and rain heads indicated there was an inadequate drip edge. This directs water into the cladding and/or underneath the butyl rubber of the gutter.

vi. The butyl rubber lined box gutters generally have only a 25mm maximum depth from the underside of the iron to the bottom of the gutter. This is not an adequate depth of gutter as it allows water from the gutter to overflow underneath the roofing iron and into the concealed cavities below the roof. This was particularly evident above the kitchen, where water ingress has caused damage to the ceiling, external wall and flooring.

Given the age of the building, we would anticipate decay damage to some if not all of this parapet, gutter and gutter support framing; in particular around the scupper outlets, as these have already all been subject to repair. Because of its design and the ability for water to have been absorbed and held in the structure for extended periods of time with no ability to dry or drain, the complete removal of the parapets is probable.

Looking down into an external rain head. Glued down on the surface.

Depth of gutter shown to be inadequate. Repairs have been made to cut back the TFC

cladding.


November 2012


8.1.3 South Elevation

Non-invasive readings shown to the south elevation.

i. The TFC cladding continues down past the floor framing and down onto the hard landscaping. This area could be deemed as base cladding, however it is not, as it is continuous with the wall cladding. With the TFC sheets in contact with the ground, it is resulting in moisture uplift. Non-invasive moisture readings were indicatively very high at the perimeter floor joists all along this elevation. It is highly likely that the perimeter floor joists will need to be replaced due to moisture damage.

ii. At the southeast corner window, exterior MC readings were elevated at the sill and jamb junctions. There is likely to be moisture damaged perimeter floor joist framing, possibly the bottom plate.

24%

24.1%

41.1% 52.3%

32.4%

25.3%

Internal measure

27.4%

66% 48.2%


November 2012


iii. At the bedroom 2 window, exterior MC readings were elevated at the sill and jamb junctions, also at bottom plate, studs and jack studs. Frame replacement of these areas would be probable.

iv. At the glass blocks to lounge window, exterior MC readings were indicatively high to the west side of the window at the sill to jamb junction.

v. The concrete block wall for the pool is abutted up against the external corner. MC readings were indicatively very high on the external and internal surface. There was visual evidence to the internal wall finishes that indicate there is excessive water ingress at this corner.

vi. Front entry portico has fibre cement cladding with a painted texture finish. The top of the portico is a flat surface showing signs of water ingress and visual degradation of the plaster finish. This structure is likely to be decay-damaged and a complete removal is likely.

Cracks evident where block wall meets exterior corner of house.


November 2012


Indicative MC reading 41.1% to top of portico.

Portico structure with flat top

surfaces.


November 2012


8.1.4 West Elevation

Non-invasive indicative readings to the west elevation. Invasive readings as noted.

i. There were high MC readings to the fixed light window at the south end of the elevation, at the sill and perimeter floor joists below the window. Invasive tests were carried out in this area. This section of wall is more than likely being damaged from the failure of the internal gutter above, therefore the entire wall framing should be replaced.

High 40% + invasive MC reading at southern corner of lounge.

Invasive

test 40% +

Invasive

test 20%

Invasive test 32%

Invasive

test 20%

39.9%

49.4%

Inside face parapet 35.3%

Fixed light window has been installed centre of this wall.


November 2012


ii. Owner noticed water coming out from the external soffit light outside lounge corner. MC readings were high, the full height of this corner. It is probable that replacement will need to be made at the perimeter floor joist and the wall stud framing at this corner.

iii. There is known water entry to the wall of the kitchen from the roof and gutter above. Indicatively high MC readings were evident from the edge of the kitchen window at the south end and as far as 600mm past the north end of the window. There were visual damages to the floor, viewable from the garage below. Replacement would be required to approximately 3.6 metres of this wall, including the perimeter floor joist.

36% invasive MC reading at northern side of window at floor joist.

39.9% indicative MC reading above kitchen window


November 2012


iv. The deck joists cantilever out from the garage from the northwest

corner to approximately line with the north side of the kitchen window, with a ribbon plate bolted directly against the cladding from that location back to the internal corner of the lounge. This will have created water entrapment at the deck to wall junction.

v. The solid balustrade portion to the deck is approximately 700mm high, clad in TFC, with the balance being stainless steel tubing connected through a flat top surface. MC readings were very high at the south end, reducing in value towards the northern end. Decay of this framing is probable; allow for removal and replacement with a compliant design.

vi. To the south side of the garage doors there was no indication of decay damage at basement level, however we recommend improving the under house ventilation through this cladding into the sub-floor area.

TFC clad balustrade with cladding directly onto deck surface and handrail fixed through top flat

surface.

Particleboard flooring in kitchen from the underside. Extreme water damage.


November 2012


vii. Narrow wall section between the single and double garage door does not have the required 150mm recommended distance between the external ground and framing. Allow for concrete nib to be installed.

viii. The deck floor joists are H3.2, and there is no indication of decay damage. However, there is evidence of water entry tracking along the joists and gaining entry to the ends of the solid blocking. One of these is showing decay damage and would need to be replaced.

The inadequate clearance of garage wall framing above

outside ground.


November 2012


Invasive measure 32%

No soffit constructed at this elevation. Window has been installed on this wall.

Hairline cracking evident on plaster finish. No inter-storey joint has been installed.

Outside of parapet 29.5%

8.1.5 North Elevation

Non-invasive readings shown to the north elevation.

i. This is a 2 storey wall; there is no H-mould inter-storey joint to this elevation. There was cracking evident at the mid-floor level. The wall is in excess of 5.4 metres in length; vertical expansion joints have not been installed.

Cracks appearing at mid-floor level.


November 2012


ii. The lounge window at the western end has the sheet cladding installed whereby it is in line with the window jambs; there was hairline cracking off the bottom of the sill to jamb junction both sides of that window. MC readings were indicatively very high below the window and continuing down the window studs. Potentially we assess the need for frame replacement to both sides of the window and at the mid-floor perimeter floor joist.

iii. The 135° wall located at the northeast corner showed visual signs of decay damaged framing internally from the upper window down to the bottom plate level. Very high MC readings were evident at the external corner on both sides. This part of the dwelling has no soffit; there is an internal gutter running across the top of the wall head. Framing replacement is expected to the corner studs on both sides and to the window studs and sill trimmers of both windows.

iv. MC readings were very high above the head of the garage window. Allow for replacement of the lintel.

Internal boxed gutter running across the top of the wall.


November 2012


Timber retaining

wall.

No soffit constructed at this elevation; window has been installed on this wall.

Location of meter box

29.5%

29.9%

Area of concern where timber framed bathroom wall meets block retaining wall.

8.1.6 East Elevation

Non-invasive readings shown to the east elevation.

i. There is an under house area below the deck. There is a timber retaining wall approx. 900mm away from the house. This area is subject to significant overland surface water flows. A review of the drains and further decision may need to be made to improve or upgrade subsoil drains behind this wall, along with improved contouring of the ground below the deck; essentially involving the cutting away and removing of the soils.


November 2012


ii. The rear wall of the downstairs bathroom junctions with a timber frame wall and potentially the concrete block retaining wall. MC readings were very high at this junction; expect timber framing to be replaced below the bathroom window to the south end. Our recommendation would be to change this section of wall to either reinforced concrete masonry or insitu concrete up to the height of the windowsill.

iii. There were elevated readings to the northern end of the master bedroom window and at the floor joist. Would expect framing replacement of the window studs and a section of the floor joists below this window.

iv. MC readings were elevated around the meter box. Allow for replacement of the studs either side of the meter box.

29.5% MC reading at the bottom edge of the

meter box.

Existing timber retaining wall with junction of bathroom wall. High moisture readings in this

area.


November 2012


8.1.7 Extent of Anticipated Timber Framing Replacement

See elevations below of extent of anticipated timber framing replacement, as detailed in red.


November 2012


9 Conclusion

Our investigation found there are numerous flaws in the construction as previously identified. In particular, the lack of ground clearance of the cladding, the design of the parapet and gutter system, and lack of sill and jamb flashings to the window joinery.

The existing roof has inadequate fall, and signs of damage to the roof edge. Given the coastal location and significant amount of mature vegetation, redesigning the building with a hip roof and bitumen tiles would be a prudent option.

From our investigation we can now determine that water ingress has occurred to the dwelling. In particular, through the boxed gutters, particularly to the west elevation; also to the north elevation above the master bedroom where there is no soffit, effectively bringing the internal gutter into the face of the dwelling.

Moisture has risen from the external ground up through the sheet cladding throughout all elevations, due to inadequate ground clearance.

The design of the window installation has meant that water is trapped in the cladding due to no installation of sill or jamb flashings, which allows the water to exit.

Territorial Authorities now have particular requirements to be met in the application for building consents, which must be achieved during the construction process before being prepared to issue Code of Compliance Certificates to dwellings with a monolithic plaster cladding system. We are aware the owners are contemplating installing a weatherboard cladding system. However, should a monolithic cladding system be considered, it is now mandatory to have a draining, drying, venting cavity. Revision of the NZ Building Act 2004 in September 2008 now requires a building consent for any repairs to a dwelling as a result of excess moisture ingress. With the indicated extent of repairs that are apparent to this dwelling, Auckland Council will require a building consent.

10 Recommendations

We recommend that a full reclad of this building and a complete new roof be undertaken together with these additional recommendations. The following list is not conclusive. Further works may be found with the remediation works.

i. The TFC cladding to be fully removed to all elevations of the building.

ii. Aluminium joinery to be removed and new jamb, head and sill liners to suit new wall depth. Due to the age of the windows, they will need to be completely refurbished. The cost may be considerable in achieving


November 2012


this, and the windows will still appear aged in their appearance. We therefore consider that new exterior joinery is the more prudent option.

iii. All decayed and damaged timber framing be removed and replaced with H3.2 treated new timber.

iv. All remaining timbers exposed during the reclad process are to be treated with Protim FrameSaver preservative.

v. Install new wall cladding.

Suggested options: Durapal Paliside bevel back profile or paint finished bevel back pine weatherboards.

vi. The front entry portico to be redesigned to incorporate correct flashing and weatherproofing.

vii. The western deck to be amended to achieve a drainage plane between deck and house.

viii. West deck balustrade to be removed and replaced with new complaint design.

ix. Correct sub-floor ventilation to ensure cross-flow.

x. New concrete nibs to be installed between the existing garage doors to provide a greater distance between external ground and framing.

xi. A review of the drains and further decision may need to be made to improve or upgrade subsoil drains behind this wall, along with improved contouring of the ground below the deck; essentially involving the cutting away and removing of the soils.

xii. Downstairs bathroom wall to be redesigned with a concrete masonry or insitu concrete wall up to windowsill height.

xiii. This work would be best undertaken as soon as possible to minimise the scope of repairs and the cost.

xiv. For this work a building consent will be required.

This dwelling is outside the timeframe whereby an application can be made to the Department of Building & Housing (DBH) for assistance with a leaky building claim and/or to apply for the FAP (Financial Assistance Package).

We recommend that the sooner some action is taken to rectify the moisture ingress into this home, the greater the likelihood is of reducing or stopping any damage that may be occurring to the light structural timber frame and thus degradation of the dwelling.


November 2012


11 Estimate of Cost to Repair

We have provided the following tables to outline the costs of the building works and professional fees.

Option 1: Remediation and repair work only

Option 2: Addition of 2nd floor work only

Option 3: Remediation / Repairs + 2nd floor addition worked on concurrently.

Please note the cost estimate carried out for the 2nd floor addition is a preliminary estimate. Until a design has been provided, these figures only serve as a guideline.


November 2012


FBC LTD Confidential 12/12/12 Page 1

Est4RepFairseaPl74a_281112.xlsx

Estimated Cost of Remediation and Repairs

to 7A Fairsea Place, Lynfield, Auckland 28/11/2012

Description Qty Unit Rate FBC Estimate Comment

OPTION 1

1 Scaffolding, tarpaulins & ground protection 1 LS 20,229.79

2 Remove existing TFC cladding and external

mounted fittings and dispose of debris. 207 m2 68.08 14,097.95

3 Remove existing doors and windows, &

dispose off site 50.2 m2 47.49 2,383.50

4 New Palliside B-backed pre-finished

weatherboards direct fixed to framing 207 m2 176.00 36,446.52

5 Supply and install new exterior windows and

doors, to match exisiting 50.2 m2 477.60 23,970.60

6 Exterior wall insulation 207 m2 11.50 2,381.45

7 External painting - N/A m2 Excl 0.00

8 Replace decayed timber and make good

damage (PROVISIONAL) 1 LS 20% 8,883.84

9 New Asphalt Shingle roof coverings, substrate

and trussed roof framing 213.7 m2 175.29 37,460.40

10 Roof flashings, rainwater plumbing and

downpipes 1 LS 5,567.96

11 Interior wall linings, replaced & painted 1 LS 4,582.51

12 Services as neccesary, remove & reinstall 1 LS 4,140.00

13 Unex Glass balustrade and deck gutter 10.2 m 460.00 4,692.00

14 Concrete nibs, channel drains & adjust ground

levels to provide compliant clearances 1 LS 4,564.50

Subtotal 1 257.3 m2 169,401.01

15 P&G - supervision, QA, comms, wc, etc 9.5% 16,093.10

Subtotal 2 185,494.11

16 Contractors Margin 10% 18,549.41

Subtotal 3 204,043.52

17 Contingency 10% 20,404.35

Subtotal 4 224,447.87

18 Building Consent, inspections and fees 1 LS 4,500.00

20 Project Management 1 LS 27,125.00

21 Architect & Drafting fees 1 LS 26,000.00

TOTAL COST (excl GST) 282,072.87

22 Plus GST 15% 42,310.93

TOTAL REPAIR ESTIMATE 324,383.80$

Exclusions:

Subfloor recladding (existing remains)

Deck repairs and replacements

Internal flooring and finishes

Internal ceiling repairs and replacements

Entry Pergola, remove & replace

CCTV video drains

New Conc block wall at Basement

Project Management


November 2012




Estimated Cost of 2nd Floor Addition



OPTION 2

1 Scaffolding, temp covers, etc 1 LS 6,502.53

2 New floor finishes and protection of extng 1 LS 7,919.63

3 Removal of extng roof cladding & framing 1 LS 5,098.57

4 Supply & Install doors & windows 1 LS 8,754.96

5 New Asphalt Shingle roof cladding and ply

substrate 1 LS 10,796.26

6 Rainwater plumbing and downpipes 1 LS 2,959.00

7 New roof framing and trusses 1 LS 5,542.50

8 Intermediate suspended floor 1 LS 11,838.71

9 Stairs, handrails and balustrades 1 LS 4,495.00

10 Exterior wall framing and cladding 1 LS 41,386.19

11 Painting - Exterior & Interior 1 LS 20,301.67

12 Interior wall framing and lining 1 LS 20,574.86

13 Services, new & disrupted 1 LS 19,840.50

14 External works 1 LS 0.00

Subtotal 1 92 m2 1814.32 166,010.36


Subtotal 2 174,310.88


Subtotal 3 191,741.97

18 Contingency 10% 19,174.20

Subtotal 4 210,916.17



TOTAL COST (excl GST) 2351.54 215,166.17

21 Plus GST 15% 32,274.93

TOTAL ADDITION ESTIMATE 247,441.09$

Exclusions:

Construction Management fees

Timber frame Consultants fees

Architect & Drafting fees

GF Kitchen alterations and upgrade

Other alterations to GF layout

Basement & Foundation upgrade

Sanitary Fittings

2-way Gas fire

Sliding/folding doors

Furniture, fittings and equipment

Special finishes

Siteworks and Landscaping


November 2012




Combined Estimated of Remediation & Additions



OPTION 3

1 Scaffolding, temp covers, etc 1 LS 26,732.32

2 Remove existing TFC cladding and external

mounted fittings and dispose of debris. 207 m2 68.08 14,097.95

2 New floor finishes and protection of extng 1 LS 7,919.63

3 Remove existing doors and windows, &

dispose off site 50 m2 47.49 2,383.50

3 Removal of extng roof cladding & framing 1 LS Incl in item 9.

4 New Palliside B-backed pre-finished

weatherboards direct fixed to GF framing 50 m2 726.17 36,446.52

5 Supply and install new exterior windows and

doors, to match exisiting 67.4 m2 485.90 32,725.56

6 Exterior GF wall insulation 67 m2 35.36 2,381.45

7 Replace decayed timber and make good

damage (PROVISIONAL) 1 LS 20% 8,883.84

8 Intermediate suspended floor 91 m2 11,838.71

9 New Asphalt Shingle roof coverings, substrate

and trussed roof framing 213.7 m2 175.29 37,460.40

9 Stairs, handrails and balustrades 1 LS 4,495.00

10 Roof flashings, rainwater plumbing and

downpipes 1 LS 8,526.96

11 New exterior wall framing and cladding 1 LS 41,386.19

12 Interior GF wall linings, replaced & painted 1 LS 4,582.51

13 Painting - Exterior & Interior 1 LS 20,301.67

14 New interior wall framing and lining 1 LS 20,574.86

15 Unex Glass balustrade and GF deck gutter 10.2 m 460.00 4,692.00

16 Existing GF services, remove & reinstall 1 LS 4,140.00

17 Services, new & disrupted to addition 1 LS 19,840.50

18 Concrete nibs, channel drains & adjust ground

levels to provide compliant clearances 1 LS 4,564.50

19 External works & Landscaping 1 LS 0.00

Savings:

Subtotal 1 m2 313,974.05 21,437.33


Subtotal 2 338,367.66


Subtotal 3 372,204.43

22 Contingency 10% 37,220.44

Subtotal 4 409,424.87



25 Architect & Drafting fees 1 LS 26,000.00

TOTAL COMBINED COST (excl GST) 471,299.87 25,939.17

26 Plus GST 15% 70,694.98

TOTAL ALTERATIONS ESTIMATE 541,994.85$


November 2012




Exclusions:

Subfloor recladding (existing remains)

Deck repairs and replacements

Internal flooring and finishes

Internal ceiling repairs and replacements

Entry Pergola, remove & replace

CCTV video drains

New Conc block wall at Basement

Timber frame Consultants fees

Architect & Drafting fees

GF Kitchen alterations and upgrade

Other alterations to GF layout

Basement & Foundation upgrade

Sanitary Fittings

2-way Gas fire

Sliding/folding doors

Furniture, fittings and equipment

Special finishes

Siteworks and Landscaping


November 2012


Thank you for selecting our firm to undertake the inspection of your property. We will remain available by telephone following receipt of this report to address points of clarification.

FORENSIC BUILDING CONSULTANTS LIMITED

Peer reviewed by: Craig Turner NDQS NDCM Dip SBM

Kim Wilson BArch


November 2012


12 Appendix 1: Understanding Weathertightness Principles

A building has to rely on several mechanisms working in combination to deal with moisture ingress. This is best described by the 4 D’s concept of deflection, drainage, drying and durability.

Deflection

Eaves and soffits greatly assist the weathertightness of a dwelling by protecting and deflecting moisture away from particularly upper areas of exterior walls. Deflection can be further provided by integrated flashings and the painted cladding surface. Monolithic homes like this are vulnerable to leakage at penetrations, junctions and through minor faults. The lack of proper head, jamb and sill flashings to joinery generally requires more than sealants or paint films can withstand on their own.

Drainage

Moisture needs to have a method to be able to escape out from within or behind building materials and cavities and not be entrapped and/or therefore absorbed. Moisture can drain down both through and behind the textured plaster coating over rigid backed cladding. However, with the cladding direct fixed to framing, drainage is inhibited at nog and plate (horizontal framing) lines, directing moisture against the timber framing where decay is likely to occur.

Drying

Drying occurs through evaporation and/or diffusion and requires space of airing or movement of air. With direct fix monolithic cladding systems there is no air movement in the wall; drying can only occur through diffusion, i.e., the movement of water vapour through either the outer paint coating or through the plasterboard lining on the interior. The drying mechanism of diffusion is slow (months) in comparison to wetting, which can happen in minutes, resulting in walls staying more or less permanently damp where leaks occur.

Durability

Building materials need to be able to withstand the conditions that they may be placed under in ordinary use. To build a house that is completely or absolutely waterproof is unrealistic. It is possible however, to build a house that has several systems working in combination to minimise the effects of moisture ingress and prevent damage to timber framing and other buildings elements if water penetration does occur.


November 2012


13 Appendix 2: Glossary

Architrave - a wooden (usually) board fixed as a frame around an opening in a wall, and covering the joint between the wall and the lining in the opening.

Balustrade - a panel beneath the handrail of a stair or verandah, made up of an arrangement of boards or shaped pieces of wood (balusters), or cast iron; most often as a decorative element.

Beam - horizontal supporting member.

Bearer - horizontal sub-floor framing member supporting joists, sitting directly on the foundations.

Blocklaying/Bricklaying:

Efflorescence - white salt-like substance on the outside faces of concrete or masonry units. It should disappear in a season. Persistent efflorescence means that the wall is permanently damp.

Perpend - a vertical mortar joint.

Boxed Corner - boards fixed over weatherboards at outside corners of a house to exclude water.

Casement - a hinged window – usually hinged at the side but sometimes at the top of the bottom.

CCC - Code Compliance Certificate, issued by the Territorial Authority after final inspection of consented building works.

Cornice - ornamental moulding around the edge of a ceiling to cover the junction between wall and ceiling.

Drainage:

Back vent - vent pipe which leads from a waste pipe to the open air to prevent the loss of water seal in the waste pipe.

Gully trap - water-sealed fitting just above ground level into which the waste pipes discharge.

Eaves - projection of the roof beyond the walls; hence: “flush eaves” – no projection, “boxed eaves” – projecting roof lined on the underside or soffit.

Electrical:

CoC - Certificate of Compliance. Must be issued by a registered electrician worker for any completed works.

TPS - Tough Plastic Sheathed (modern wiring)

Elevations - exterior view of building, in a two-dimensional form.

EIFS - External Insulation Finish System (polystyrene sheet based plaster clad system).

Fascia - board under the edge of the roof at the eaves, to support spouting and to divert water away from the wall.

Flashing - folded metal strips fixed around junctions in roof coverings to prevent entry of water; also around openings in walls for the same purpose.

Foundations - base of the building up to timber plates and bearers.

Galvanised - iron or steel coated with zinc.


November 2012


Jack - term used to indicate that a member is less than full-length. Thus a jackstud is not a full-length stud.

Jamb - part of a wall either side of a door or window opening.

Joists - regularly spaced framing members supporting the floor or ceiling.

Lintel – the beam above a window or door opening.

MC - moisture content

Pile - foundation member.

Plumb - upright, vertical.

Purlin - regularly spaced horizontal roof member set out to accommodate the roofing material.

Rebate - recess machined out of a piece of timber to form a stop for the fitting or fixing of doors, glass, etc.

Ridge - apex of roof.

R-value - level of effectiveness of insulation.

Scriber - thin batten with one edge cut to the shape of the wall covering material and fixed to the edge of an architrave or boxed corner, to exclude water.

Soaker - folded metal sheet nailed over joints in weatherboards, especially at mitred corners of a wall.

Soffit - under-surface, usually of the eaves.

Spalling - delamination of concrete, due to expansion of reinforcing steel from corrosion, as a result of moisture ingress into a reinforced concrete structure.

Stucco - coat of plaster applied over a wall surface as both decorative and weathering finish.

TFC - Texture over Fibre Cementboard.

Truss - prefabricated structural roofing element.

Wicking - the action of liquid/moisture being drawn up by capillary action.

forensic building consultants ltd · po box 27254 mt roskill auckland 1440 nz t +64 9 636 3485 f...

Documents