2.3 Fastening EPS / XPS / Graphex board - to timber / steel frame

There must be no horizontal surfaces which will be subject to water ponding; a minimum slope of 5 degrees is required (for metal caps only, 10 degrees for liquid membranes). Check EPS/XPS insulation board supplied is the correct; type, grade and thickness.

2.6.1.Ground Clearances

Refer to Rockcote TradeSpec™ 1.2.5 Ground Clearances

2.6.2.Wall Alignment

Using a straight edge, check joints are smooth and that the wall is flat and true.

2.6.3.Builder Supplied Flashings

Make sure all builder supplied flashings are in place. (Refer to Rockcote TradeSpec™ document 3.2 Builder Supplied Flashings) for a list of possible builder supplied flashings.

2.6.4.Rockcote Flashing Installation

Refer to the flashings as outlined within the Rockcote RenderSpec™ section 5 and refer to their installation procedures in Rockcote TradeSpec™ document 3.1 Rockcote Flashings

2.6.5.Control/Expansion Joint Set outs

for more information about control joints refer to TradeSpec™ Document 1.4 – Control Joints

2.6.6.Substrate Installation

EPS Sheet

All EPS insulation boards must be installed; vertically, be fully supported on all edges and butt-jointed hard against each other. Where a sheet join is fully supported on timber framing, one nail and washer may be used to fix both sheets.. Any gaps between sheets must not be greater than 5mm. All gaps must be foam filled. (Refer to Rockcote TradeSpec™ 3.6 Low Expansion Adhesive Foams).

Fix EPS insulation boards with fasteners and washers as given in the Table 1 – Fastener Sizes

Fix fasteners into studs at the fixing centres shown in Table 2 – Fastening centres.

Fixings must be flush with the recess in the washer, so that the washer is hard against the EPS insulation board, and pulls the sheet hard back against the framing / batten.

XPS Sheet

All XPS insulation boards must be installed; horizontally, in a stretcher bond pattern, and butt-jointed hard against each other. Tongue & Grooved edges do not need support. Butt joints without Tongue & Groove edges require back blocking / framing support. Any gaps between sheets must not be greater than 5mm. All gaps must be foam filled. (Refer to Rockcote TradeSpec™ 3.6 Low Expansion Adhesive Foams)

Fix XPS insulation boards with fasteners and washers as given in the Table 1 – Fastener Sizes

Fix fasteners into studs at the fixing centres shown in Table 2 – Fastening centres.

Fixings must be flush with the recess in the washer, so that the washer is hard against the XPS insulation board, and pulls the sheet hard back against the framing / batten.

 Table 1 – Fastener Sizes

8g x 100 mm ** 8g x 100 mm **

Substrate Thickness (mm)

Timber Frame Nail size

Timber Frame Screw size

Steel Frame Screw size

40mm +20mm Batten

90 x 3.55 mm *

8g x 80 mm **

8g x 80 mm **

50mm +20mm Batten

110x 3.55 mm *

8g x 100 mm **

60mm +20mm Batten

110x 3.55 mm *

8g x 100 mm **

60mm (no batten)

90 x 3.55 mm *

8g x 80 mm **

8g x 80 mm **

* Nail type = Galvanised flat head
** Screw type = Class 4, countersunk

 Table 2 – Fastening centres

NZS 3604 Building Wind Zones

Fastening centres (mm)

Low

300

Medium

300

High

300

Very High

200

Note: One fixing is also required into each dwang and top and bottom plates at mid-nog length.

NZS3604 Wind Zone Extra High and Specifically designed buildings up to 2.5kPa design differential ULS wind pressure with studs at maximum 400mm centres.
Maximum vertical fixing centres (mm) along studs Maximum horizontal fixing centres (mm) along top and bottom plates Maximum horizontal fixing centres (mm) along dwangs
150 200 150