Butynol® and Butyseal Roofing Membrane Systems
- Appraisal number 436
- 7 January 2019
- Valid from
- Information provider
- BRANZ Limited
- Information type
- BRANZ Appraisal
Butynol® and Butyseal Roofing Membrane Systems are synthetic rubber waterproofing membranes designed to be used on roofs and decks.
The membranes are supplied as single-ply, flexible synthetic rubber sheet in roll form. The products are installed as single layer systems.
Butynol® and Butyseal Roofing Membrane Systems have been appraised for use as roof and deck waterproofing membranes for buildings within the following scope:
- the scope limitations of NZBC Acceptable Solution E2/AS1, Paragraph 1.1; or,
- the scope limitations of NZBC Acceptable Solution E2/AS1 with regards to building height and floor plan area when subject to specific engineering design; and,
- with substrates of plywood sheet, Strandsarking (roofs only) or suspended concrete slab; and,
- with deck size limited to 40 m2; and,
- situated within NZS 3604 Wind Zones up to, and including Extra High; or,
- situated in specific design wind pressures up to a maximum design differential Ultimate Limit State (ULS) of 6.0 kPa with the weathertightness detailing subject to specific design.
Roofs and decks must be designed and constructed with no steps within the deck level, no integral roof gardens, and no downpipe discharging directly onto the deck.
The design and construction of the substrate and movement and control joints is specific to each building, and is therefore the responsibility of the building designer and building contractor and is outside the scope of the Appraisal.
The membranes must be installed by trained applicators, approved by ARDEX New Zealand Limited.