Fixing Recommendations

Superdek sheets should be laid into the prevailing wind and sit neatly on the preceding roof sheet, as shown in the laying procedure below. They should be fixed at the recommended support spacings. Avoid ‘stretching' the width of the sheet when installing, as this could allow wind and rain to enter. Due to its higher rib height, flashing turn downs into the pan of Superdek should always be notched around the rib to provide maximum weather tightness. Pan fixing is only suitable for walling, carport and verandah applications or where weather tight roofing is not essential. When spans exceed 900mm for roofing or 1200mm for walling, it is recommended the side laps are fixed at mid-span to ensure a weatherproof seal and to secure the overlap, especially when the roof is walked on occasionally. Use either 8 x 12mm self drill stitching screws or 3.2mm sealed blind rivets. On roofing, at the end of the sheets, the pans should be turned up at crest of the roof and down into the gutter using a turn up/down tool.

Superdek Fixing and Laying Directions - Non-Cyclonic Areas

Note: The following recommendations apply to non-cyclonic areas.

• All fasteners must have neoprene washers.
• Roofing - Each crest requires one fastener.
• Walling - Each pan requires one fastener. Fasten adjacent to overlapping rib.
• Side lap fixing is recommended to maintain a weather proof seal and secure the overlap, especially when the roof is walked on occasionally. Use either 8x12 mm self drill stitching screws or 3.2 mm sealed blind rivets.
• It is recommended side lap fasteners are secured mid-span when spans exceed 900mm for roofing and 1200mm for walling.
• The below fastener sizes are suitable for fixing over an insulation blanket up to 55mm thick. For thicknesses up to 100mm, the next standard screw length to that indicated is to be used.

Superdek Fastener Selection
	ROOFING Crest fixing	WALLING Pan fixing
Fixing to Steel Self drilling and tapping screw with neoprene washer	12 x 45mm or TS M6 x 50mm*	10 x 16mm
Fixing to Timber Type 17 hex head screw with neoprene washer	12 x 65mm or TS M6 x 650mm	10 x 25mm
Laying procedure

Walking on Superdek

When walking on Superdek roofing, it is recommended you walk over the purlins to avoid any damage. Wear flat, rubber soled shoes and walk flat footed in the sheet pans only. For carport and verandah applications, use crawl boards to avoid damage during installation and maintenance.

Using Superdek

Stratco Superdek will have a long, useful life if used according to Stratco specifications. While roofing materials in outer urban and rural areas may have a life-span in excess of 30 years, this can reduce to only a few years in coastal and industrial environments.

Zinc/alum and pre-painted steel should not be used in very aggressive areas such as near swimming pools and spas. It is important that dirt, soil, compost, paving sand, or other materials which retain moisture are not placed against steel sheeting. Concrete should not be poured against zinc/alum material. Check with Stratco before using in these severe environments.

Incompatible Metals

The best way of reducing corrosion is to keep incompatible metals apart. Zinc/alum and prepainted steel cannot be used with lead, copper and monel. Galvanised steel and pure zinc material can be used with zinc/alum, but you must avoid water run-off from zinc/alum onto galvanised material. Fixings such as rivets and self-drilling screws must be compatible with the material they are fixing.

Handling and Cutting of Superdek

For safety, wear gloves when handling Superdek. Ensure your hands or gloves are clean, especially when handling zinc/alum which can mark. Use a coloured pencil for marking steel, as lead or black pencils contain graphite which promotes rusting. Superdek is best cut using tin snips, but for larger cuts it may be necessary to use a power saw with a steel cutting blade or a power nibbler. Avoid using abrasive discs as they can cause burred edges and coating damage. Where possible cut sheets on the ground, and always clean off any swarf and metal filings progressively during the installation. Dispose of off-cuts carefully.

Insulation and Sealants

The use of blanket insulation is recommended in domestic roofing to assist in temperature, condensation and sound control. Superdek can be used with an insulating blanket up to 55mm thick. Increased thicknesses require longer fasteners and greater care when installing.

When choosing a silicone sealant, ensure it is suitable for roofing and guttering use and of a non-acetic, amine free, neutral cure type. Sealants that smell of ammonia, vinegar or lemons are not usually suitable.