ITI BC-RP-IM-V5 User manual

BC-RP-IM-V5
www.ititimspec.nz
Bevelback Cavity System
Radiata Pine
Installation Manual
V5 - 2021

CertClad | Bevelback Cavity System | Radiata Pine | Installation Manual
© ITI Timspec Ltd | BC-RP-IM-V5 | CertClad is a registered Trademark of ITI Timspec Ltd
Last Updated March 2021 1
**IMPORTANT**
This Installation Manual (IM) is specific to
RADIATA PINE (RP) and BEVEL BACK cavity system (BC) profile only.
Specific drawings in this Installation Manual can be found at the back.
There are 9 CertClad Installation Manuals in the following profiles and timber species.
Profiles are Bevel Back, Vertical Shiplap and Rusticated. The timber species are Accoya,
Western Red Cedar and Radiata Pine.
CertClad is a certified installation system and supplied by ITI Timspec.
You can find these documents on our website www.ititimspec.nz/downloads. If you have any
questions, please feel free to contact us. Auckland office [phone] or
[e-mail]

CertClad | Bevelback Cavity System | Radiata Pine | Installation Manual
© ITI Timspec Ltd | BC-RP-IM-V5 | CertClad is a registered Trademark of ITI Timspec Ltd
Last Updated March 2021 2
CONTENTS
SCOPE .............................................................................................................................................. 4
1.1 INTENDED USE ................................................................................................................................. 5
1.2 VALIDITY........................................................................................................................................ 5
1.3 PERFORMANCE ................................................................................................................................. 5
1.4 LIFESPAN ........................................................................................................................................ 5
HEALTH AND SAFETY ........................................................................................................................ 6
2.1 CUTTING OF TIMBER.......................................................................................................................... 6
2.2 COATING AND PRIMING ...................................................................................................................... 6
SITE PREPARATION............................................................................................................................ 7
3.1 STRUCTURE AND FRAMING .................................................................................................................. 7
3.2 BUILDING UNDERLAY ......................................................................................................................... 7
PRE-INSTALLATION........................................................................................................................... 8
4.1 ON-SITE STORAGE AND HANDLING ....................................................................................................... 8
4.2 DOCKING OUT DEFECTS..................................................................................................................... 8
4.3 PRIMING AND SEALING ....................................................................................................................... 8
MATERIALS - CAVITY SYSTEM COMPONENTS ..................................................................................... 9
5.1 CAVITY SYSTEM COMPONENTS ........................................................................................................... 9
5.2 TIMBER SPECIES:RADIATA PINE ............................................................................................................ 9
5.3 RADIATA PINE BEVELBACK WEATHERBOARDS............................................................................................ 9
5.4 FLASHINGS.................................................................................................................................... 10
5.5 NAILS .......................................................................................................................................... 10
5.6 CAVITY BATTENS ............................................................................................................................ 10
MATERIALS - ACCOMPANYING ELEMENTS ........................................................................................ 11
6.1 ACCOMPANYING ELEMENTS ............................................................................................................... 11
6.2 TIMBER FRAMING............................................................................................................................ 11
6.3 BUILDING UNDERLAY ....................................................................................................................... 11
6.4 FLASHING TAPE.............................................................................................................................. 11
6.5 SEALANTS AND ADHESIVES ................................................................................................................ 11
6.6 PEF ROD...................................................................................................................................... 12
6.7 METER BOX ................................................................................................................................... 12
6.8 INTERNAL LINING............................................................................................................................ 12
INSTALLING CAVITY BATTENS.......................................................................................................... 13
7.1 CAVITY CONSTRUCTION ................................................................................................................... 13
FIXING DETAILS FOR WEATHERBOARD.............................................................................................. 14
8.1 INSTALLATION ............................................................................................................................... 14

CertClad | Bevelback Cavity System | Radiata Pine | Installation Manual
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INTER-STOREY CAVITY JUNCTION ................................................................................................... 15
9.1 DEFINITION................................................................................................................................ 15
WITHIN-BOARD JOINS (SCARF JOINT) ............................................................................................... 16
10.1 LIMITATIONS ................................................................................................................................. 16
10.2 METHOD ...................................................................................................................................... 16
SITE CLEAN-UP ............................................................................................................................... 17
11.1 AT COMPLETION ........................................................................................................................ 17
ON-GOING MAINTENANCE .............................................................................................................. 18
12.1 MAINTENANCE INTERVAL .................................................................................................................. 18
12.2 MAINTENANCE REQUIREMENTS ........................................................................................................... 18
CONSTRUCTION DETAILS ................................................................................................................ 19
CONTACT....................................................................................................................................... 41

CertClad | Bevelback Cavity System | Radiata Pine | Installation Manual
© ITI Timspec Ltd | BC-RP-IM-V5 | CertClad is a registered Trademark of ITI Timspec Ltd
Last Updated March 2021 4
TABLE OF FIGURES
FIGURE 13. 1 BC 106 PAINT FINISH WITH STANDARD CAVITY FIX ................................................................................19
FIGURE 13. 2 BC 108 STAIN FINISH WITH STANDARD CAVITY FIX ................................................................................20
FIGURE 13. 3 BC 201 WINDOW HEAD –ALUMINIUM JOINERY .......................................................................................21
FIGURE 13. 4 BC 202 WINDOW JAMB –ALUMINIUM JOINERY ........................................................................................22
FIGURE 13. 5 BC 203 WINDOW SILL –ALUMINIUM JOINERY ..........................................................................................23
FIGURE 13. 6 BC 301 INTERNAL CORNER NOTCHED & SCRIBED ...................................................................................24
FIGURE 13. 7 BC 302 INTERNAL CORNER MOULDING ..................................................................................................25
FIGURE 13. 6 BC 401 INTER-STOREY CAVITY JUNCTION..............................................................................................26
FIGURE 13. 7 BC 402 WITHIN BOARD JOINS (SCARF JOINT) ..........................................................................................27
FIGURE 13. 8 BC 403 BOXED CORNER.........................................................................................................................28
FIGURE 13. 9 BC 404 CORNER SOAKER .......................................................................................................................29
FIGURE 13. 10 BC 501 BASE, TIMBER FLOOR ..............................................................................................................30
FIGURE 13. 11 BC 502 BASE, CONCRETE SLAB ON GROUND ........................................................................................31
FIGURE 13. 12 BC 503 BASE, JUNCTION WITH BOTTOM OF CLADDING/ CLADDING FINISH ABOVE DECK .......................32
FIGURE 13. 13 BC 601 ROOF/ WALL TOP PLATE –FLAT SOFFIT....................................................................................33
FIGURE 13. 14 BC 602 ROOF/ WALL TOP PLATE –NO SOFFIT ......................................................................................34
FIGURE 13. 15 BC 701 PARAPET/ CAPPING –EXPANSION JOINT ...................................................................................35
FIGURE 13. 16 BC 702 BALUSTRADE INTERSECTION WITH THE WALL ...........................................................................36
FIGURE 13. 17 BC 801 METER BOX HEAD....................................................................................................................37
FIGURE 13. 18 BC 802 METER BOX JAMB.....................................................................................................................38
FIGURE 13. 19 BC 803 METER BOX SILL.......................................................................................................................39
FIGURE 13. 20 BC 851 PIPE PENETRATION DETAIL.......................................................................................................40

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SCOPE
1.1 INTENDED USE
This Bevelback Weatherboard Cavity System has been designed for use as cladding for residential and
light commercial buildings. It is suitable for buildings with a ‘Risk Score’ of 0 - 20 Calculated in accordance
with New Zealand Building Code (NZBC) Clause E2/AS1 Table 1 and Wind Zones up to and including extra
high.
1.2 VALIDITY
Cerclad is only valid when all products in the weatherboard system are as listed in the product certificate
and in this manual. This is to ensure that all products meet the requirements of Certclad and are installed
in the correct manner.
1.3 PERFORMANCE
When installed and maintained as specified in this manual and the work is done by a qualified tradesman
using accepted trade practices, it will meet the applicable sections of the following requirements of the
NZBC (New Zealand Building Code):
•B1 Structure
•B2 Durability
•E2 External Moisture
•F2 Hazardous Building Materials
1.4 LIFESPAN
1.4.1 SERVICEABLE LIFE
ITI Timspec Radiata Pine is warranted for between 15 –40 years depending on coating selected.
This serviceable life is subject to the coating and maintenance requirements below. More importantly, some
timber boards may require replacement over the lifetime of the cladding as part of normal maintenance.
1.4.2 COATING REQUIREMENTS
For H3.1 or H3.2 treated Radiata Pine with a dressed surface, all faces (hidden and exposed) must be
paint finished, consisting of two coats of an approved primer and all exposed faces coated with a further
two coats of a suitable topcoat, refer to chapter 4.3 (Priming and Sealing, page 7) and 6.2.4 (Coating, page
8) for more detail.
1.4.3 MAINTENANCE REQUIREMENTS
When a coating is applied, periodic maintenance and recoating is required to ensure the integrity of the
coating is sustained. This will generally mean applying another exterior coat every 10 years dependent on
the coating used and building location after washing and maintenance.
Please refer to the On-Going Maintenance section 12 (page 18) for more information about the required
maintenance.

CertClad | Bevelback Cavity System | Radiata Pine | Installation Manual
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HEALTH AND SAFETY
2.1 CUTTING OF TIMBER
Cutting of timber is to be done in a well-ventilated area and a suitable dust mask, eye protection, and ear
protection must be worn.
2.2 COATING AND PRIMING
Coating and priming are to be done in a well-ventilated area, refer to the coating/primer supplier for all
matters relating to health and safety. All relevant sections of AS/NZS 2311:2009 (Guide to the painting of
buildings) and all of the coating manufacturer’s requirements must be adhered to.
Contact Information is technica[email protected]; [phone] or www.ititimspec.nz

CertClad | Bevelback Cavity System | Radiata Pine | Installation Manual
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SITE PREPARATION
3.1 STRUCTURE AND FRAMING
3.1.1 NEW ZEALAND STANDARD 3604
Generally, the timber framing must comply with NZS 3604 (2011) (Timber-framed buildings), however,
where specific engineering design is required the framing shall be at least of equivalent stiffness as the
framing provisions of NZS 3604 (2011).
3.1.2 LAYOUT
Studs must be at spaced at a maximum of 600mm between centres. Dwangs (nogging) must be spaced at
maximum 800mm between centres. Studs and Dwangs must form a flush plane for cavity battens and
weatherboards to be fixed to.
Additional framing may be required at soffits, corners, and penetrations such as window and door openings
to support the installation of battens and flashings.
3.1.3 MOISTURE CONTENT
The optimum moisture content of the weatherboards is between 16 - 18%. The moisture content must not
exceed 20% at the time of fixing as problems may occur with the coating adhesion.
3.2 BUILDING UNDERLAY
3.2.1 MATERIAL
Building underlay and Rigid wall underlays must comply with properties stipulated in NZBC Clause E2/AS1
Table 23 (Properties of roof underlays and building underlays) or equivalent proof of compliance to NZBC.
3.2.2 INSTALLATION
Building underlay to be installed in accordance with underlay manufacturer’s specification, and in
accordance with conditions set out in NZBC Clause E2/AS1. 9.1.7.2.

CertClad | Bevelback Cavity System | Radiata Pine | Installation Manual
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PRE-INSTALLATION
4.1 ON-SITE STORAGE AND HANDLING
Care must be taken to ensure that timber and accessories are kept clean and dry, and are not damaged
whilst in storage awaiting application.
Extra care is to be taken while handling timber to ensure that it is not damaged.
Timber is to be stacked on flat level bearers/dunnage that is a maximum of 900mm apart and at least
100mm off the ground. Timber should either be stored inside an enclosed building or covered with an
additional waterproof layer and protected from the elements when stored outside
IMPORTANT Radiata Pine weatherboards should not be installed if their moisture content is above
20%.
4.2 DOCKING OUT DEFECTS
Before coating or installing boards, check for any defects that may require docking out.
IMPORTANT All docked ends, any exposed or bare timber of painted weatherboards will require end
sealing with a minimum of two coats of primer.
4.3 PRIMING AND SEALING
Apply the first coat of primer to all sides and edges of the weatherboard prior to installation. It is critical that
Radiata Pine is at the correct moisture content prior to priming. Remember that all docked ends will require
priming as noted above. Follow the coating manufacturer’s directions and ensure further coats are applied
as required. All relevant sections of standard AS/NZS 2311 (Guide to the painting of buildings) must be
adhered to.

CertClad | Bevelback Cavity System | Radiata Pine | Installation Manual
© ITI Timspec Ltd | BC-RP-IM-V5 | CertClad is a registered Trademark of ITI Timspec Ltd
Last Updated March 2021 9
MATERIALS - CAVITY SYSTEM COMPONENTS
5.1 CAVITY SYSTEM COMPONENTS
All cavity system components must be supplied by, or approved by ITI Timspec. This is to ensure that all
items are up to a suitable standard and to ensure the compatibility and suitability of all items. Any
alternative or competitor supplied product will invalidate the Certclad Warranty.
5.2 TIMBER SPECIES: RADIATA PINE
5.2.1 MATERIAL
New Zealand grown Radiata Pine (Pinus Radiata) which has been preservative treated to a minimum H3.1
(ACQ, CCA, etc.) level.
5.2.2 DURABILITY
ITI Timspec Radiata Pine is warranted for between 15 –40 years depending on coating selected.
The above Warranty assumes regular maintenance. Please refer to the On –Going Maintenance Section
12 for more information.
Please note, some timber boards may require replacement over the lifetime of the cladding as part of
normal maintenance.
5.2.3 COATING
Dark colours attract more heat which will exacerbate any timber movement and/or resin bleed. Therefore
only coatings which have an LRV (light reflectance value) of 45% or higher can be used. Any coating that
has an LRV less than 45% will void the warranty.
5.2.4 IMPORTANT NOTES
Timber treated with a copper-based treatment (ACQ, CCA, etc.) should not be in contact with metal wall
claddings as this may lead to corrosion. Separation is required in the form of an approved DPC.
Material selection to be in accordance with NZBC Clause E2/AS1 Table 21 compatibility of materials in
contact and Table 22.
5.3 RADIATA PINE BEVELBACK WEATHERBOARDS
Radiata Pine can be machined into a variety of profiles, including the range of Bevelback weatherboards as
listed on our Website.
5.3.1 COATING DRESSED AND/OR TREATED WEATHERBOARDS
H3.1 or H3.2 treated painted finish Radiata Pine must have a dressed surface and must be coated with two
coats of primer and two further coats of a suitable alkyd or 100 percent acrylic paint. All relevant sections of
standard AS/NZS 2311 (Guide to the painting of buildings) should be adhered to.
All cut ends must be coated with a minimum of one coat of primer before installation. Immediately after
fixing the weatherboards, all nail holes should be spot-primed and filled, and sanded smooth prior to
painting.