The roofing/walling shall be Stramit CapacityPLUS™660 Deep Roof Cladding in continuous lengths with trapezoidal ribs approximately 50mm high, spaced at 220mm centres.

Sheeting material shall be 0.42mm (or 0.48mm) bmt G550 protected steel sheet to Australian Standard AS1397, with a minimum yield stress of 550MPa (Grade G550) and an AM100/AZ150 or ZMa210 coating with an oven-baked paint film of selected colour, or a plain AM125/AZ150 coating.

The sheeting shall be fixed to the purlins/girts in accordance with the manufacturer’s recommendations. Suitable fixing screws in accordance with Australian Standards AS3566, Class 3, shall be used at every rib at every support with side lap fasteners installed at mid span if required. A minimum length of 50mm shall be provided for projection into gutters.

Flashings shall be supplied in compatible materials as specified; minimum cover of flashing shall be 150mm. All sheeting shall be fixed in a workman-like manner, leaving the job clean and weather-tight. Repair minor blemishes with touch-up paint supplied by the roof manufacturer. All debris (nuts, screws, cuttings, filings etc.) shall be cleaned off daily.

Class 4 fasteners should be used <1km from the coast.

A NATSPEC work section is available for this product. Download

Cyclonic data for Stramit CapacityPLUS™660 Deep Roof Cladding can be found in the Stramit Cyclonic Areas Guide.

Information on the use of Stramit CapacityPLUS™660 Deep Roof Cladding in the Darwin area can also be found in deemed-to-comply sheets No M/147/01. This is available from Stramit or on the NT BAC website.

Stramit CapacityPLUS™660 Deep Roof Cladding can be fixed with 3 fasteners per sheet at each batten/purlin to meet the required performance values.

All external fastening screws must conform to AS3566 – Class 3. They are to be hexagon headed and must be used with sealing washers for both roofing and walling.

For connecting to purlins or top hats in non-cyclonic regions use:

Note*: Lengths shown are suitable for use with insulation blanket up to 50mm. For 75mm of 100mm insulation blanket increase screw length by at least 10mm. 

The Stramit Cyclonic Areas Manual has fixing details for cyclonic areas.

Foot traffic limits for Stramit CapacityPLUS™660 Deep Roof Cladding Stramit are shown for 3 alternative foot traffic categories:

High Maintenance – for applications with repeated maintenance, particularly where personnel may be unfamiliar with correct procedures for walking on metal roofs.

Normal – based on traditional expectations, with moderate maintenance foot traffic using designated footpaths.

Controlled – spans that conform to AS1562 with 1.1kN load specified in AS/NZS1170.1 for R2 - Other Roofs. These require minimal careful foot traffic only on the designated footpath. Suggested for use only where occasional aesthetic imperfections from foot traffic are acceptable.

Tables are based on tests to AS1562.1 and AS4040 parts 0 and 1.

For more information on foot traffic performance of Stramit's roofing profiles refer to Stramit's Foot Traffic Guide.

Stramit CapacityPLUS™660 Deep Roof Cladding is manufactured from G550 colour coated steel, aluminium-zinc-magnesium or zinc-aluminium alloy coated steel. In some locations galvanised and severe environment colour coated steel may be available by arrangement.

Colour coated steels are in accordance with AS/NZS2728 – Category 4 and, for the substrate, with AS1397. Aluminium-zinc-magnesium alloy coated AM100/AM125 or ZMa210, zinc-aluminium alloy coated AZ150 and galvanised Z450 conform to AS1397.

Stramit has a comprehensive range of colours as standard. Ask at your nearest Stramit location for colour availability.  

The minimum roof slope for Stramit CapacityPLUS™660 Deep Roof Cladding is 1 degree.

Stramit CapacityPLUS™ 660 Deep Roof Cladding may be gently spring-curved, concave and convex, including curved ridges, provided it is sealed at the apex, and within recommended limits. These limits are yet to be determined.

For more information on spring curving CapacityPLUS™ 660 cladding contact your nearest Stramit office.

All metal roof sheeting is subject to thermal expansion and this needs to be accommodated where there is a temperature difference between the sheeting and the structure.

The colour of the sheeting will affect the amount of thermal expansion, and whether the sheet is flat or cured will affect its ability to resist without problems. Sheet lengths should be limited as follows.

The maximum length of sheeting can be extended through the use of special caps with slotted ribs.

Stramit CapacityPLUS™660 Deep Roof Cladding has excellent water-carrying capacity enabling roof slopes to be as low as 1° for many applications.

Roof run lengths are the combined lengths of all roof elements contributing to a single pan drainage path. This can include the roof length upstream of a roof penetration that concentrates flow into other pans.

The table below gives slopes for 100 year return period rainfall intensity.

Values are given for normal roof drainage applications, where the minimum slopes are calculated as for other Stramit® roofing profiles. 


Based on AS1562.1


For more information on water carrying performance of Stramit CapacityPLUS™660 Deep Roof cladding and other Stramit roofing profiles refer to Stramit's Roof Slope Guide.

Derived from testing, the following tables give the wind load resistance for both serviceability and strength limit states.

Tables are based on testing to AS1562.1 and AS4040 parts 0 and 2. Internal spans must have both end spans 20% shorter. 

Values only valid for use with steel support members of 1.5mm or thicker. Where thinner supports are used, fastener capacity must be checked.

Refer to Stramit® Cyclonic Areas Roof and Wall Cladding Brochure for information on use in Cyclonic Regions. 

Stramit CapacityPLUS™660 Deep Roof Cladding is readily installed with or without fibreglass insulation blanket. If practical lay sheets in the opposite direction to prevailing weather.

Installation of Stramit CapacityPLUS™660 is a straightforward procedure using the following fixing sequence.

• Ensure all girts are in line and correctly installed and that mesh and blanket (if specified) are in place.
• Position and fix the first sheet. Ensure that screws are not overtightened.
• Continue to fix subsequent sheets checking that sheet ends at the lower edge are exactly aligned.
  It is important that the underlap of one sheet does not protrude beyond the overlap of the next at the low end of the run – if this is unavoidable, the underlap must be trimmed locally or water "drawback" may occur. 
• Measure the overall cover width at top and bottom of the sheets from time to time to avoid ‘fanning’.
• For roof spans exceeding 1500mm and wall spans exceeding 1800mm, stitch the side laps at midspan. 
• Clean up the roof after each days work, removing all screws, cuttings, swarf etc, and leave roof clean and watertight.

As with all roofing products, we recommend extra caution be taken when walking on the roof. When walking on Stramit CapacityPLUS™660 cladding  roofing always wear flat rubber soled shoes and place feet only in the pans, taking care to avoid the last pan or two near edges of the metal roof area. Walk only in pans, or on ribs at purlin supports.