Include cross references to other sections where these contain related work.

Refer to 4851 EXTERIOR HANDRAILS AND TIMBER BALUSTRADES

Refer to 8422 TIMBER STRUCTURES, DECKS AND PERGOLAS (If using Masterspec Landscapes)

Include cross references to other sections where these contain related work.

BPN in accordance with AS 4586: 2013 Slip resistance classification of new pedestrian surface materials  Appendix A Wet Pendulum Test Method

SRV cited in NZBC is the mean BPN of a sample set.

Delete from the DOCUMENTS clause any document not cited.  List any additional cited documents.

The following are related documents and if referred to in the work section need to be added to the list of DOCUMENTS.

It is important to ensure that all personnel on site have access to accurate, up to date technical information on the products, materials, accessories  and other equipment used on a project.  In most cases individual products are not used in isolation, but form part of a building process.  Also a particular manufacturer's and/or supplier's requirements for handling, storage, preparation, installation, finishing and protection of their product can vary from what might be considered the norm.  Access to technical information can help overcome this potential problem.

The heartwood of an individual piece of timber may vary from the species nominated classification.

Hermpac recommends the use of Wood-X "Clear Base" Oil and does not recommend the use of tinted oils or stains.

Not all hardwood timbers are available with FSC certification.  Profile and volumes may result in extended lead times and/or affect supply capabilities.    Please check with Hermpac – technical@hermpac.co.nz for current supply information.  Co-ordinate with other related timber work sections. Modify clause if required.  Delete if not required.

This guidance note describes the use of Masterspec slip resistance clauses.  The extent of slip resistance clauses included within this section is subject to Q&A and section requirements.  Ensure the section 1278SR SCHEDULE OF SLIP RESISTANCE TESTING is included in the specification

NZBC D1/AS1, Table 2 identifies walking surfaces that are level or sloping access routes (including stairs) under dry and wet conditions that either:

• Have acceptable slip resistance to D1/AS1, Table 2 without testing.  Use the clause SLIP RESISTANCE - SURFACES EXEMPT FROM TESTING.
• Require testing to prove slip resistance.  Use the clauses SLIP RESISTANCE - PREVIOUSLY TESTED SURFACE or TEST - SLIP RESISTANCE as appropriate.
• Are not acceptable to, or outside the scope of D1/AS1 Table 2.  Surfaces in this category may be evaluated as an alternative solution based on testing (and may require alternative testing).  Use the clauses SLIP RESISTANCE - PREVIOUSLY TESTED SURFACE or TEST - SLIP RESISTANCE as appropriate.

Note:

• If the surface is already tested, use clause SLIP RESISTANCE - PREVIOUSLY TESTED SURFACE.
• If the surface is not tested (& testing is required) use clause TEST - SLIP RESISTANCE

Exceptions to wet slip resistance requirements for level access routes (refer NZBC D1/AS1, 2.1.2) include:

• Situations where safety matting is provided.
• For housing wet slip resistance applies only to the access route on the approach to the main entrance and not inside that entrance and not on the approach to other entrances.

Check project walking surfaces against Table 2 to confirm acceptable solution relates to project requirements.  Identify compliant walking surfaces if this section also includes surfaces to be tested, or surfaces previously tested.

For stairs wet with slip resistant nosings at least 50mm wide, acceptability criteria for stair treads is based on requirements for level surfaces (39 SRV, equivalent to 39 BPN).  For stairs wet without slip resistant nosings a minimum test value of 50 BPN is required.

Hermpac has not undertaken any testing to date for Kanda or Tonka/Cumaru.  Contact Hermpac for further information on slip resistance of Accoya®.

Use when the surface has not been tested and the contractor is required to undertake the testing.

Ensure the section 1278SR SCHEDULE OF SLIP RESISTANCE TESTING is included in the specification, as it is required to supplement TEST - SLIP RESISTANCE clause content.

Delete clause if FSC timber is not required.  Modify clause if required.

Not all hardwood timbers are available with FSC certification.  Profile and volumes may result in extended lead times and/ or affect supply capabilities. Check local supply capabilities. Co-ordinate with other related timber work sections.

Modify to suit by deleting Watershed, Promenade/Boardwalk or Custom-Profiled  depending on what is specified.

Refer Hermpac Decking Species Guide for information on your selected hardwood - natural charateristics, surface checking/splits, raised grain and leaching and length spread/average length.

Each timber species has unique characteristics that should be considered to ensure selection of a suitable timber for the proposed application. Hardwood decking is a natural product and while the level of leaching will vary from species to species, some leaching is to be expected  – refer https://www.hermpac.co.nz/media/6238/decking_species_guide_a3.pdf

A wide range of profiles available, including custom options (check suitability of species and profile for proposed application). FSC timber is available if required.  Volumes and lead times may affect supply capabilities.  Contact Hermpac – technical@hermpac.co.nz.  Co-ordinate with other related timber work sections.

A wide range of profiles available, including custom options (check suitability of species and profile for proposed application).  FSC timber is not available.  This timber is considered “NC – non controversial”.  Volumes and lead times may effect supply capabilities.  Contact Hermpac – technical@hermpac.co.nz.  Co-ordinate with other related timber work sections.

A selected range of profiles available (check suitability of species and profile for proposed application).  FSC timber is available if required.  Volumes and lead times may effect supply capabilities.  Contact Hermpac – technical@hermpac.co.nz.  Co-ordinate with other related timber work sections.

A selected range of profiles available (check suitability of species and profile for proposed application).  Kanda has FSC certification, if required.  Volumes and lead times may effect supply capabilities.  Contact Hermpac – technical@hermpac.co.nz.  Co-ordinate with other related timber work sections.

A selected range of profiles available (check suitability of species and profile for proposed application).  Accoya® has FSC certification, if required.  Volumes and lead times may effect supply capabilities.  Contact Hermpac – technical@hermpac.co.nz.  Co-ordinate with other related timber work sections.

A wide range of profiles available, including custom options (check suitability of species and profile for proposed application).  FSC timber is available if required.  Volumes and lead times may effect supply capabilities. Contact Hermpac – technical@hermpac.co.nz.  Co-ordinate with other related timber work sections.

A wide range of profiles available, including custom options (check suitability of species and profile for proposed application).  FSC timber is not available.  This timber is considered “NC – non controversial”.  Volumes and lead times may effect supply capabilities.  Contact Hermpac – technical@hermpac.co.nz.  Co-ordinate with other related timber work sections.

Available in a range of promenade/boardwalk profiles, including custom options (check suitability of species and profile for proposed application).  FSC timber is available if required.  Volumes and lead times may effect supply capabilities.  Contact Hermpac – technical@hermpac.co.nz.  Co-ordinate with other related timber work sections.

Available in a range of promenade/boardwalk profiles, including custom options (check suitability of species and profile for proposed application).  Accoya® has FSC certification, if required.  Volumes and lead times may effect supply capabilities.  Contact Hermpac – technical@hermpac.co.nz.  Co-ordinate with other related timber work sections.

Accoya®/Accoya Grey® will permanently soak up CCA from framing when the timber is wet.  In all cases there should be an impermeable moisture barrier installed between decking and the frame.  Not required for other timber species.

Delete clause if not relevant to contract.

Not required for Accoya®/Accoya Grey®.  Recommended on all hardwood applications.

Delete clause if not relevant to contract.

Not required for Accoya®/Accoya Grey®.

Application of a quality hardwood decking oil will assist to stabilise boards, minimise surface checking and splitting, and  slow moisture transference in and out of the boards as the decking  acclimitises into it’s environment.

All hardwood decking (whether left uncoated or coated with a clear oil) will change to its weathered colour/silver off over time. Weathering time depends on the amount of direct exposure to UV and other environmental factors.

Accoya®/Accoya Grey® will permanently soak up CCA from framing when the timber is wet.  In all cases there should be an impermeable moisture barrier installed between decking and the frame.  Not required for other timber species.

Refer BRANZ Build Supplement 139 – Timber Decks

Board spacing for hardwood  decking is very important.  The New Zealand climate varies considerably depending on regions and seasons, and these factors must be taken into account.  Other factors that must be considered are timber species and its movement characteristics, dryness of the timber at the time of laying, width and thickness  of the board, and distance from ground or waterproof membrane under the boards.  As a guide, the wider the board - the more movement can be expected.

Refer https://www.hermpac.co.nz/media/6238/decking_species_guide_a3.pdf

For 65mm x 21mm decking it is possible to use one 65mm x 12 gauge screw fixed centrally in the board.

Hermpac does not recommend the use of wide board decking (115mm and wider)  over a waterproof membrane or where the decking will be within 300mm of ground level.  When decking is being used over a waterproof membrane ensure that the membrane is compatible with the hardwood decking oil.

NOTE: Screw fix where slats are required to be removed when necessary for maintenance to membrane below for an enclosed deck.

Refer to Hermpac for specific fixing options to suit project.

Secret fix decking option available with some Accoya/Accoya Grey profles – contact Hermpac for further information.

Use this clause if  NZBC D1/AS1, Table 2, requires a surface to be tested (or if the surface is outside the scope of Table 2) and the contractor is to organize the test.

Ensure the section 1278SR SCHEDULE OF SLIP RESISTANCE TESTING is included in the specification, as it is required to supplement TEST - SLIP RESISTANCE clause content.

Not all hardwood timbers are available with FSC certification.  Profile and volumes may result in extended lead times and/or affect supply capabilities.    Please check with Hermpac – technical@hermpac.co.nz for current supply information.  Co-ordinate with other related timber work sections. Modify clause if required.  Delete if not required.

Options:

Refer to NZS 3604, clause 7.4.3, Decking, for maximum joist spacing.

Hermpac hardwood timber decking is to be kiln dried to a "dry deck" moisture content avg 18-20%.

Hermpac Accoya®/Accoya® Grey decking has a moisture content of avg 3-5%.

Options:

Refer to NZS 3604, clause 7.4.3, Decking, for maximum joist spacing.

Hermpac hardwood timber decking is to be kiln dried to a "dry deck" moisture content avg 18-20%.

Hermpac Accoya®/Accoya® Grey decking has a moisture content of avg 3-5%.

Options:

Refer to NZS 3604, clause 7.4.3, Decking, for maximum joist spacing.

Hermpac hardwood timber decking is to be kiln dried to a "dry deck" moisture content avg 18-20%.

Hermpac Accoya®/Accoya® Grey decking has a moisture content of avg 3-5%.

Options:

Refer to NZS 3604, clause 7.4.3, Decking, for maximum joist spacing.

Hermpac hardwood timber decking is to be kiln dried to a "dry deck" moisture content avg 18-20%.

Hermpac Accoya®/Accoya® Grey decking has a moisture content of avg 3-5%.

Nosings:         Reference appropriate nosing section.

Refer to NZS 3604. Delete clause if not required.

For stairs wet with slip resistant nosings at least 50mm wide, acceptability criteria for stair treads is based on requirements for level surfaces (39 SRV, equivalent to 39 BPN).  For stairs wet without slip resistant nosings a minimum test value of 50 BPN is required.  Refer to SLIP RESISTANCE - PREVIOUSLY TESTED SURFACE clause.

Accoya®/Accoya Grey® will permanently soak up CCA from framing when the timber is wet.  In all cases there should be an impermeable moisture barrier installed between decking and the frame.  Not required for other timber species.

If a Machinecoat factory finish is specified, all cut ends and end grains are required to be coated during installation – no second coat required on site.

Not required for Accoya®/Accoya Grey®.

If a site coat is specified then it must be applied to all 6 sides prior to installation.  During installation all cut ends and end grains are required to be coated on site – no second coat required.

Not required for Accoya®/Accoya Grey®.