Fixing and fasteners
The requirements of foundations, sub-floor framing, bracing, decking selection, fastenings and fixings are in NZS 3604:2011 section 7.4.
1. All steel fixings and fastenings to be type 304 stainless steel minimum.
2. Steel fixings used in timber treated with copper-based preservatives to be a minimum of type 304 stainless steel.
3. Stainless steel nails must be annular grooved so that they have similar withdrawal resistance to galvanised nails.
4. Nails and screws may be hot-dip galvanised except when the timber has been treated with copper quaternary and copper azole in which case, type 304 stainless steel must be used. In accordance with NZS 3604:2011 Tables 4.1 and 4.3 must still be met.
5. Decking should be installed with a 12 mm minimum gap between the building cladding and the decking for drainage and maintenance.
6. All structural fixings in sheltered and exposed locations are to be stainless steel (minimum grade 304).
Where the deck is part of the main access into the building, the grooved face must be uppermost and the decking should be laid perpendicular to the direction of the traffic. If a deck is not part of an access route, the smoother side, which is easier to keep clean, may be laid face up.
1. Water absorbing mats may be necessary around swimming pool surrounds, pool ramps and stairs leading to water.
2. Standards Australia HB 198:2014 Table 3B provides guidance for pedestrian surfaces for particular applications.
Safety from falling
Should you have an elevated deck with stairs, you may require handrails and/or railing, and may need to consult with an engineer on the regulatory requirements.
External stairs on the access route into a house may provide access to a deck or across a sloping site. If they are part of the main access route to the house, they must comply with NZBC clause D1 Access routes.
The Acceptable Solution D1/AS1 is quite prescriptive, including requirements for stair pitch, riser height, tread depth, projections or nosing, where open risers may be used, stair width, handrails and slip resistance.
For common and main private stairways, the permitted dimensions in D1/AS1 are:
Maximum pitch – 37°
Maximum riser height – 190 mm
Minimum tread depth – 280 mm
For more information, please download installation manual.
Download Brochure & Installation Guide