Description

The StoStucco Render Cavity System is a cavity-based monolithic render wall cladding. It is designed to be used as an external wall cladding system for residential and light commercial type buildings where domestic construction techniques are used.

The system consists of a stainless steel lath fixed over timber battens to form the cavity. The coating system consists of an approximate 18 mm thick polystyrene bead saturated, polymer-modified, cement-based render applied to the lath, an approximate 2.5 mm thick coat of mesh reinforced synthetic resin render, and an approximate 1-3 mm thick coat of coloured finishing render. The render is then finished with a Sto coating.

The system incorporates a primary and secondary means of weather resistance (first and second line of defence) against water penetration by separating the cladding from the external wall framing with a nominal 25 mm wide cavity.

Scope

1. The StoStucco Render Cavity System has been appraised as an external wall cladding system for buildings within the following scope:

• the scope limitations of NZBC Acceptable Solution E2/AS1, Paragraph 1.1; and,
• with a risk score of 0-20, calculated in accordance with NZBC Acceptable Solution E2/AS1, Table 2; and,
• situated in NZS 3604 Wind Zones up to, and including Extra High'.

2. The StoStucco Render Cavity System has also been appraised for weathertightness and structural wind loading when used as an external wall cladding system for buildings within the following scope:

• the scope limitations of NZBC Acceptable Solution E2/AS1, Paragraph 1.1 with regard to building height and floor plan area; and,
• constructed with timber framing subject to specific engineering design; and,
• situated in specific design wind pressures up to a maximum design differential ultimate limit state (ULS) of 2.5 kPa.

3. The StoStucco Render Cavity System must only be installed on vertical surfaces (except for tops of parapets, sills and balustrades, which must have a minimum 10º slope and be waterproofed in accordance with the Technical Literature).

4. The system is appraised for use with aluminium window and door joinery that is installed with vertical jambs and horizontal heads and sills. (Note: The Appraisal of the StoStucco Render Cavity System relies on the joinery meeting the requirements of NZS 4211 for the relevant Wind Zone or wind pressure.)

5. Installation of components and accessories supplied by Stoanz Limited and Sto registered contractors must be carried out only by Sto registered contractors.