3.2 Check and Prepare Fibre Cement Sheet Substrates

Preparation based on new substrate installations.

2.3.1.Preliminary Checks

Fibre cement sheet – please refer to substrate manufacturers installation instructions.

Vermin proofing track (supplied and installed by main contractor as per cement sheet manufacturer instructions). The vermin proofing track can be manufactured from uPVC, aluminium or stainless steel and must be punched with 3-5 mm holes or slots complying with NZBC Acceptable Solution E2/AS1, Paragraph to provide ventilation openings of 1000 mm2 per lineal metre.

Other cement sheet flashings may be required as determined by the substrate supplier.

2.3.2.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.

2.3.3.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

2.3.4.Control/Expansion Joint Set outs

All control joints are the responsibility of the main contractor / substrate installer. Control joints must comply with the substrate supplier’s specifications.

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

2.3.5.Clean Surface

When the substrate has been left for a period of time, dust and dirt may build up on the surface. This contamination must be removed prior to render application.


Before application of Render, apply masking to all joinery, pipes, roofs and all areas likely to be marked by the Render. Use drop cloths and ground covers to keep the working areas clean.

2.3.7.Colour selection

For further information on Light Reflectance Values (LRV) refer to TradeSpec™ Document 1.6 – Light Reflectance Values

2.3.8.Rebated fibre cement sheet

When coating rebated fibre cement sheet joints, rebated edges must occur on all opposing sheet joints.