WANZ Window Installation System WIS Document - 01 July 2005.pdf · NZS 4223: Code of Practice ... Part 3:1999 Part 4: 2000 AS/NZS 4284:1995 Testing of Building Facades ... 3.0 WANZ

WANZ Window Installation System An Alternative Solution for the Installation of Windows & Doors

Window Installation System 1 July 2005

_____________________________________________________________________________________________________ Window Association of New Zealand Page 2 of 65

Contents

Page

References 3

Definitions 4

1.0 Objective 5

2.0 Scope 5

2.1 Cavity Cladding Systems 5

2.2 Direct Fix Cladding Systems 5

3.0 WANZ Window Installation System 5

3.1 The Project Team 5

3.2 Cladding Junctions & Window Support 6

4.0 System Overview 6

4.1 Preparation of the Opening 6

4.2 Window Installation 6

4.3 Preparation of Opening 6

4.4 Cavity Construction 6

4.5 Direct Fix Claddings 7

5.0 Testing 8

5.1 Verification Method E2/VM1 8

5.2 AS/NZS 4284:1985 8

5.3 The Test Samples 9

6.0 Cavity Construction 10

Step 1 – Preliminary Check of Sill Trimmer 11

Step 1a – Building Wrap Preparation 12

Step 2 – Flexible Sill Flashing 13

Step 3 – Upper Corners 14

Step 4 – Unit Support for Openings with Wall Framing

15

Step 4a – Unit Support for Openings at Floor Level

16

Step 5 – Position Unit in Opening 17

Step 6 – Fix off Inside of Unit 18

Step 6a – Fix off Inside of Unit 19

Step 7 – Air Seal 20

Step 8 – Cavity Closer 21

Step 9 – Battens 22

Step 10 – Head Flashing 23

Step 11 – Cladding 24

Components 25

Brick Veneer 26

Brick Veneer Alternatives 27

Stucco – Recessed Window 28

Stucco – Flush Window 29

Bevel Back Weatherboards 30

Rusticated Weatherboards 31

Fibre Cement Weatherboards 32

Horizontal Profiled Metal 33

Fibre Cement Sheet 34

Plywood Sheet 35

EIFS – Recessed Window 36

EIFS – Flush Window 37

7.0 Direct Fix 38

Step 1 – Preliminary Check of Sill Trimmer 39

Step 1a – Building Wrap Preparation 40

Step 2 – Flexible Sill Flashing 41

Step 3 – Upper Corners 42

Step 4 – Sill Pan 43

Step 5 – Unit Support for Openings with Wall Framing

44

Step 5a – Unit Support for Openings at Floor Level

45

Step 6 – Position Unit in Opening 46

Step 7 – Fix off Inside of Unit 47

Step 7a – Fix off Inside of Unit 48

Step 8 – Air Seal 49

Step 9 – Head Flashing 50

Step 10 – Cladding 51

Bevel Back Weatherboards 52

Rusticated Weatherboards 53

Vertical Shiplap Weatherboards 54

Board & Batten 55

Fibre Cement Weatherboards 56

Vertical Profiled Metal 57

Fibre Cement Sheet 58

Plywood Sheet 59

EIFS – Recessed Window 60

EIFS – Flush Window 61

Concrete Block 62

Precast Concrete Panel 63

Appendix A 64

Summary of Test Reports 65



References

Reference was made while compiling this document to the following: Standards New Zealand AS/NZS 1734:1997 Aluminium and Aluminium Alloys NZS 3504:1979 Specification for Aluminium Windows NZS 3604:1999 Timber Framed Buildings NZS 4211:1985 Specification for Performance of Windows NZS 4203:1992 General Structural Design and Design Loadings for Buildings NZS 4223: Code of Practice for Glazing in Buildings Part 1:1985 Part 3:1999 Part 4: 2000 AS/NZS 4284:1995 Testing of Building Facades Building Industry Authority Approved Document for New Zealand Building Code, External Moisture E2: Verification Method E2/VM1 Acceptable Solution E2/AS1 The New Zealand Building Code B1 Structural B2 Durability E2 External Moisture F2 Hazardous Building Materials Other Organisations NZ Metal Roof and Wall Cladding Code of Practice NZMRM September 2003 The Brick Book 1st Edition 2000



Definitions

The following is an abbreviated list of words and terms of particular relevance to the WANZ Window Installation System. Air seal: A continuous water resistant seal around the perimeter of the window or door, fitted between the window or door jambliners and the wall framing. Holds pressure in the trim cavity and enables pressure equalisation by preventing air flow to the interior of the building. Typically an air seal is a low expansion foam or sealant, with an optional PEF rod. Building Wrap: A building paper, synthetic wrap or sheathing used as part of the wall cladding system to assist the control of moisture by ensuring moisture which occasionally penetrates the wall cladding is directed back to the exterior of the building. Cavity Batten: A vertical packing member used to create a drained cavity as part of a cladding system. Cavity Wall: A term used to describe a wall that incorporates a drained cavity. Cladding: The external weather resistant surface of the building; includes supporting components and surface treatment. Cladding System: The weatherproof enclosure of a building including building wraps, claddings, fixings, flashings, seals, joints, junctions and window/door penetrations. Direct Fixed: A term used to describe a wall cladding attached directly to the wall framing without the use of a drained cavity. Drained Cavity: A cavity space immediately behind the wall cladding that has the ability to ventilate and drain water that occasionally penetrates the cladding system. Flexible Flashing Tape: A flexible self adhesive waterproof tape used in conjunction with the building wrap to protect the wall framing along the sill, upper corners and intersections. Head Flashing: Fixed to the cavity battens at the head of the window or door, it deflects or drains water to the outside of the cladding system.

Pressure Equalisation: The term used to describe the equalising of pressures between the trim cavity and the exterior of the building. When achieved air flow between the two spaces is eliminated. Sill Pan: A flashing used for direct fix claddings designed to collect and drain water that may penetrate through the window or door unit. It extends from the inner most point of the aluminium frame, out and over the external face of the cladding. It runs the full width of the trim opening with upstands at both ends. Specific Design: A term to describe methods outside the scope of the WANZ Window Installation System. Trim Cavity: The space between the window or door frame perimeter and the wall framing. Unit Support: A term to describe the method used to provide a continuous support across the sill of a window or door unit for either cavity construction or direct fixed claddings. WANZ Cavity Closer: A flashing device that closes the cavity above the window or door unit thus directing water that occasionally penetrates the wall cladding into the cavity spaces adjacent to the window. The WANZ cavity closer directs the water to the back face of the cladding or wet side. Note, substitute cavity closers are not acceptable for use with the tested WANZ WIS Alternative Solution. WANZ Support Bar: The extruded aluminium support bar provides continuous support to the window unit. The support bar has been independently tested for the loads imposed and includes built in drainage and ventilation as required by NZBC E2. Note, substitute support bars are not acceptable for use with the tested WANZ WIS Alternative Solution. WANZ Support Angle: Used in conjunction with the sill pan for deeper claddings to transfer the weight of the window unit back to the structure. Wind Zone: The categorisation of wind force experienced on a particular site or region as determined in NZS 3604: 1999.


WANZ Window Installation System

An Introduction to the Step by Step Guides.

Window Association Of New Zealand Page 5 of 65

1.0 Objective

The primary objective, and the Mission Statement throughout the development process, was “To provide a quick and easy installation method, applicable to all residential window installations, regardless of wind zone.” It was agreed that whilst the system needed to address the issues of weathertightness in an innovative and robust manner, in order to gain industry-wide acceptance it could not depart too far from traditional window installation methods. The secondary objective was to prepare and support the system in such a way that it would be readily accepted as an ‘Alternative Solution’ to the details described in E2/AS1. 2.0 Scope

The WANZ Window Installation System (WANZ WIS) covers the weathertightness of aluminium window and door installation into the external walls of the building envelope. The scope of this document is limited to the installation of aluminium windows and doors into the external walls of buildings within the scope of Clause 1.1.2 of NZS 3604:1999, and meets or exceeds the performance requirements for Low, Medium, High and Very High Wind Zones. WANZ WIS applies to claddings installed either on to a cavity system, in accordance with E2/AS1, or directly fixed to timber framing. Installations that fall outside the scope of this document will require Specific Design by a suitably qualified person. Specifically the claddings covered by WANZ WIS are: 2.1 Cavity Cladding Systems;

a) Brick Veneer b) Stucco c) Bevel Back Weatherboards d) Rusticated Weatherboards e) Fibre Cement Weatherboards f) Horizontal Profiled Metal g) Fibre Cement Sheet h) Plywood Sheet i) EIFS

Note: Window and door installation into cavity cladding systems assumes that the installation can make use of the building cavity. For situations where the window or door is rebated back to the framing line, then these details will fall outside the scope of this document.

2.2 Direct Fix Cladding Systems; a) Bevel Back Weatherboards b) Rusticated Weatherboards c) Vertical Shiplap Weatherboards d) Board and Batten e) Fibre Cement Weatherboard f) Vertical Profiled Metal g) Fibre Cement Sheet h) Plywood Sheet i) EIFS j) Concrete Block (untested) k) Precast Concrete Panel (untested)

The materials used in the preparation of the trim opening and for use as window installation components shall be in accordance with the durability requirements of NZBC Clause B2, suitable for their end use and compatible with adjoining materials. Whilst the test specimens used in assessing WANZ WIS included windows, it was only the junction between the window and cladding elements that were assessed in the tests. Window and door units must be tested in accordance with NZS 4211:1985, to the appropriate wind zone or specific design wind pressure. A Note to Specifiers: WANZ recommends that specifiers note within their specification that, “Windows and Doors shall be a WANZ member product with each unit labelled as complying with NZS4211:1985 and installed in accordance with the WANZ Window Installation System: July 2005. 3.0 WANZ Window Installation System

3.1 The Project Team WANZ WIS is the result of three years of research development and testing by the WANZ Technical Committee. The members of this committee are comprised of representatives of the Technical, Design and R&D personnel of each of the Proprietary Systems Suppliers of Aluminium Joinery to the New Zealand building industry. This group represents the vast majority of window brands marketed in this country who work together on providing solutions to window industry issues. Accordingly each, of the major window brands support WANZ WIS and provide their own brand specific literature that supports this industry endorsed solution. The WANZ Window Installation System, including the technical details and its components, are a result of the combined effort and hard work of this team of industry representatives.



3.2 Cladding Junctions & Window Support The WANZ Window Installation System project was undertaken to meet the demands of the building industry for improved weathertightness. It was decided that the best way of dealing with the issues was to take “Ownership of the Junction” between the window and building envelope, an area which in the past had fallen into ‘no man’s land’. In addition to taking ownership of the junction it was realised that the issue of window support had long been overlooked and that this could be dealt with as part of the same solution. Consultation with the wider industry was an important part of the development process and involved input from major cladding suppliers, industry experts on weathertightness, BRANZ and the BIA. The end result is the system described in this document, the WANZ Window Installation System, or as it has affectionately been termed ‘WANZ WIS’. 4.0 System Overview WANZ WIS is a pressure equalised installation system, consisting of two main parts; 4.1 Preparation of the Opening This is about protecting the structure from moisture that might enter the space (trim cavity) around the window or door. This part of the system was primarily designed for use with timber framing, as the major construction type in this country, and uses a combination of the building wrap and a ‘flexible flashing’ to prevent moisture being absorbed into the structure. The flexible flashing is a butyl backed self adhesive tape which runs continuously across the full length the sill, returns 200mm up each jamb and is used as a patch in the upper corners.

Note: The flexible flashing tape must be compatible with the building wrap. Check with the wrap supplier for their recommendation on the correct tape for use with their product.

4.2 Window Installation This is about reducing the risk of water ingress through attention to design and detail. Pressure Equalisation is a theory that has been used in the design of curtain wall systems since the 1960’s. Water leakage depends on three essentials; i) water, ii) an opening, and iii) some kind of force to move the water through the opening. Equalising the pressures between the trim cavity and the exterior of the building prevents water being carried between the two by eliminating one of these essentials, air flow. This is achieved by providing a water resistant ‘air seal’ at the inside edge of the window or door opening.

Note: The air seal is the most important component of WANZ WIS and must be continuous around the

perimeter of the opening. The material recommended is a low expansion polyurethane foam. The seal is an air barrier only and must not fill the trim cavity. Use of a PEF backing rod to control the depth of the seal is optional.

At all times during its development the system was measured against the ‘Four D’s of Weathertightness’ Deflection, Drainage, Drying and Durability. D1 Deflection

WANZ WIS is designed to reduce the risk of water ingress by deflecting it away from potential weak points. This is achieved through not only the use of head flashings, jamb scribers, etc but primarily through the pressure equalisation of the trim cavity.

D2 Drainage

It is accepted that whilst the system will deflect away the bulk of the water, at some point it may enter the trim cavity and must then be drained away. For direct fix claddings the ‘sill pan’ and 5mm sill gap allow water to be drained to the exterior of the cladding. When the cladding is fixed over a cavity then the ‘WANZ support bar’ will move any water to the back face of the cladding (or the wet side of the cavity).

D3 Drying

Wherever water is being drained, then residual moisture will be left behind and this must be dried. The same areas that allow the drainage and pressure equalisation to occur also provide air flow and therefore ventilation and drying of the trim cavity.

D4 Durability

And of course the materials being used must be suitable for the situation and comply with NZBC Clause B2, Durability.

4.3 Preparation of the Opening Part of the original objective for the WANZ WIS project was to ensure it applied “to all residential window installations”, and in order to achieve this it needed to provide solutions for both direct fix claddings and cavity construction. The Preparation of the Opening (WANZ WIS Part 1) which consists of; i) the cutting and preparation of the building wrap and ii) the application of the ‘flexible flashing’, is the same regardless of cladding type. However, from this point on, the Window Installation (WANZ WIS Part 2) varies slightly dependent upon cladding / construction type. 4.4 Cavity Construction The method of installation for Cavity Construction has been based on drained cavities as described in NZBC Clause E2, i.e. those with a 20mm nominal cavity behind the cladding. A step by step installation



procedure is included as a part of this document, and is summarised as follows.

Steps 1, 2 & 3

As mentioned above in clause 3.2 the preparation of the window opening, Steps 1 to 3 inclusive, are identical regardless of cladding type.

Step 4 - Support for Unit

An extruded aluminium bar has been designed specifically for this purpose and provides continuous support to the window or door frame. The ‘WANZ support bar’, is supplied with a series of pre-punched holes that will drain any water to the back face of the cladding (or the wet side of the cavity). Note: The WANZ support bar has been independently tested to provide support for the loads imposed by the windows or doors and is required for all units. The support bar includes built in drainage and ventilation as required by NZBC Clause E2. Substitute support bars are not acceptable for use with the tested WANZ WIS Alternative Solution.

Step 5 - Position the Unit

The unit is positioned into the opening with a 5mm minimum gap between the jambliner and sill trimmer, and a nominal 5mm gap elsewhere. The depth of the jambliners should position the window with sufficient clearance for the battens and cladding.

Step 6 - Fix the Unit

Insert flat packers between the wall framing and jambliners on all sides and fix the unit in place.

Note: Use mechanical fixings only (not adhesives), positioned at approximately 150mm from the corners and at 450mm centres maximum between in between these corner fixings. Fixings should also be aligned with mullions, transoms, and door strikers.

Step 7 - Air Seal

On the inside of the building, apply a continuous bead of water resistant ‘air seal’ around the perimeter of the window or door opening, between the window reveal and the wrapped building framing.

Note: Do not fill the cavity. Use of a PEF backing rod to control the depth of the seal is optional.

Step 8 - Cavity Closer

An extruded PVC flashing device has been designed specifically for this purpose and drains any water entering the building cavity above the window into the cavity spaces adjacent to the window. The ‘WANZ cavity closer’, is designed to drain water to the back face of the cladding (i.e. the wet side of the cavity). Substitute cavity

closers are not acceptable for use with the tested WANZ WIS Alternative Solution.

Step 9 - Battens

Fix the cavity battens vertically over the wall framing. Note: Where the cavity and cladding extend above the window into a gable end or another level, the battens must be positioned or designed so that they provide adequate ventilation into the cavity space directly above.

Step 10 - Head Flashing

The head flashing is cut at least 60mm wider than the window or door unit and is fixed to the cavity battens. When installed, the head flashing overhangs the window by at least 30mm on each side.

Step 11 - Cladding

The exterior cladding can now be installed in accordance with the ‘Manufacturers Recommendations’.

4.5 Direct Fix Claddings A step by step installation procedure for Direct Fix Claddings is included as a part of this document, and is summarised as follows.

Steps 1, 2 & 3 As mentioned above in clause 3.2 the preparation of the window opening, Steps 1 to 3 inclusive, are identical regardless of cladding type.

Step 4 - Sill Pan

The ‘sill pan’ is a flashing designed solely for the purpose of collecting any water that might leak through the window or door unit. It extends from the inner most part of the aluminium frame out over and down the face of the exterior cladding for the full width of the opening.

Step 5 - Support for Unit 5mm unit support blocks are fixed or glued into place on top of the sill pan at the recommended fixing centres. The glue is simply to hold the packing in place until the load is placed on it as the base of the sill tray should not be punctured with fixings.

Note: For deeper claddings a support angle may be required to transfer the weight of the window back to the structure.

Step 6 - Position the Unit

The unit is positioned into the opening with a 5mm minimum gap between the jambliner and sill trimmer, and a nominal 5mm gap elsewhere. The depth of the jambliners should position the window so that there is a 5mm minimum



ventilation gap between the back of the window facing and the face of the sill pan.

Note: The gap at the sill is permanently left open.

Step 7 - Fix the Unit

Insert flat packers (i.e. packers that have parallel load bearing surfaces) between the wall framing and jambliners on all sides and fix the unit in place.

Note: Use mechanical fixings only, (not adhesives)

positioned at approximately 150mm from the corners and at 450mm centres maximum in between these corner fixings. Fixings should also be aligned with mullions, transoms, and door strikers.

Step 8 - Air Seal

On the inside of the building, apply a continuous bead of water resistant ‘air seal’ around the perimeter of the window or door opening, between the window reveal and the wrapped building framing.

Note: Do not fill the cavity. Use of a PEF backing rod

to control the depth of the seal is optional. Step 9 - Head Flashing

The head flashing is cut at least 60mm wider than the window or door unit and is fixed over the building wrap. When installed, the head flashing overhangs the window by at least 30mm on each side.

Step 10 - Cladding

The exterior cladding can now be installed in accordance with the ‘Manufacturers Recommendations’.

Note: The gap at the sill is permanently left open.

5.0 Testing

As explained earlier, one of the objectives of the WANZ WIS project was to prepare and support the system in such a way that it would be readily accepted as an ‘Alternative Solution’ to the details described in E2/AS1. In order to do that it was a prerequisite that the system be tested for compliance with NZBC Clause E2 External Moisture, which was carried out as follows. 5.1 Verification Method E2/VM1 The Verification Method E2/VM1 is the Department of Building & Housing approved test method used to determine compliance with NZBC Clause E2 for windows, doors and cladding systems and utilises the weathertightness testing procedure of AS/NZS 4284:1995 to the performance criteria detailed in E2/VM1. The tests must be undertaken in a test facility with IANZ accreditation to AS/NZS 4284:1995

and is only applicable to windows installed into buildings where there is a 20mm nominal cavity behind the cladding. i.e. This Verification Method is only applicable to Cavity Construction. The E2/VM1 test procedure consists of; 1. Preconditioning – Applying a preconditioning load

of 1360 Pa for a period of one minute positive pressure, followed by one minute negative pressure.

2. Series 1 Static Pressure Water Penetration –

Application of water at a specified rate initially for a period of five minutes, followed by a period of fifteen minutes at the specified positive differential air pressure of 500 Pa, as described in clause 7.5 of AS/NZS 4284:1995.

3. Series 1 Cyclic Pressure Water Penetration –

Application of water at a specified rate for a period of five minutes at cyclic pressures of 150 Pa to 300 Pa, followed by a period of five minutes at cyclic pressures of 300 Pa to 600 Pa, as described in clause 7.6 of AS/NZS 4284:1995.

4. Series 2 Water Management Testing – Steps 1 &

2 repeated following the formation of 6mm diameter holes through the wet wall in at least four locations around the window perimeter.

Note: The introduction of defects is intended to simulate the failure of the primary weather defence / sealing. This allows the water management of the cavity to be assessed.

5. Series 3 Wet Wall Test – Following the removal

of the layers behind the wet wall that support the air pressure, application of water with an air pressure of 50 Pa for a period of 15 minutes.

Note: Non-compliance or failure occurs when water (or any evidence of water) is present or has transferred to the plane of the building wrap, after carrying each of the tests described above.

5.2 AS/NZS 4284:1995 Because the Verification Method E2/VM1 is only applicable to Cavity Construction, the Direct Fix Cladding system was tested in a similar way using the modified version of the weathertightness testing procedure from AS/NZS 4284:1995. Again the tests were undertaken in a test facility with IANZ accreditation to AS/NZS 4284:1995. The modified AS/NZS 4284:1995 test procedure consists of;

1. Preconditioning – Applying a preconditioning load of 1360 Pa for a period of one minute



positive pressure, followed by one minute negative pressure, similar to E2/VM1.

2. Water Penetration Test by Static Pressure –

Application of water at a specified rate to a positive differential air pressure of 300 Pa, as described in clause 7.5 of AS/NZS 4284:1995.

3. Water Penetration Test by Cyclic Pressure -

Application of water at a specified rate to cyclic pressures of 150 Pa to 300 Pa, followed by cyclic pressures of 300 Pa to 600 Pa, as described in clause 7.6 of AS/NZS 4284:1995.

5.3 The Test Samples In accordance with E2/VM1, the test units consisted of 2.4m x 2.4m timber framed wall, with an aluminium framed fixed light window 1.6m x 1.2m fitted with clear acrylic jambliners. The building wrap, trim opening and windows were installed as per the WANZ Window Installation System details and instructions. See Appendix A for a summary of the Test Reports. The actual reports can be viewed on the WANZ website at www.wanz.org.nz

2400

1600

1200

2400


Window Association of New Zealand Page 64 of 65

Appendix A

Summary of Test Reports


Window Association of New Zealand Page 65 of 65

Summary of Test Reports The following tests were carried out to demonstrate the compliance of the WANZ Window Installation System with NZBC Clause E2 ‘External Moisture’. Testing was carried out by a registered test technician, in an IANZ accredited test facility with registration to perform tests in accordance with AS/NZS 4284:1995. Test Report No. 05/09

Tests on sample Cavity Fixed Bevel Back Weatherboard clad, timber framed wall panel fitted with insert window installed using WANZ WIS installation details for Cavity cladding systems in accordance with NZBC clause E2/VM1.

Date of Test: 7 April 2005

Summary:

Series 1 Static Pressure Water Penetration Test: No water penetration observed Series 1 Cyclic Pressure Water Penetration Test: No water penetration observed Series 2 Static Pressure Water Management Test: No water penetration observed Series 2 Cyclic Pressure Water Management Test: No water penetration observed Series 3 Wet Wall Test: No water transfer to plane of building wrap

Test Report No. 05/10

Tests on sample Cavity Fixed Stucco Plaster clad, timber framed wall panel fitted with insert window installed using WANZ WIS installation details for Cavity cladding systems in accordance with NZBC clause E2/VM1.


Summary:



Tests on sample Cavity Fixed Fibre Cement Sheet clad, timber framed wall panel fitted with insert window installed using WANZ WIS installation details for Cavity cladding systems in accordance with NZBC clause E2/VM1.


Summary:



Tests on sample Direct Fixed Bevel Back Weatherboard clad, timber framed wall panel fitted with insert window installed using WANZ WIS installation details for Direct Fixed cladding systems in accordance with AS/NZS 4284:1995 Testing of Building Facades.

Date of Test: 14 June 2005

Summary:

Static Pressure Water Penetration Test: No water penetration around or below window installation detail

Cyclic Pressure Water Penetration Test:

No water penetration around or below window installation detail

Copies of the actual test reports can be viewed on the Window Association of New Zealand’s website at www.wanz.org.nz.

Documents

WANZ Window Installation System WIS Document - 01 July 2005.pdf · NZS 4223: Code of Practice ... Part 3:1999 Part 4: 2000 AS/NZS 4284:1995 Testing of Building Facades ... 3.0 WANZ