Materials
Stramit Monoclad® cladding is manufactured from hi-tensile G550 BHP Colorbond® XRW steel or BHP Zinculame® steel. In some locations galvanised and Colorbond XSE steel may be available by arrangement. Colorbond XRW (and XSE) is in accordance with AS2728 - Category 3 and, for the substrate, with AS 1397. Zincalume AZ 150 and galvanised Z450 conform to AS 1397.
Sheeting Mass (kg/m2 of roof area)
Zincalume
Colorbond
Galvanised
0.42mm BMT
4.28
4.35
4.65
0.48mm BMT
4.86
4.93
5.23
Spring Curving
Stramit Monoclad® cladding can be spring-curved, concave and convex, including curved ridges, provided it is sealed at the apex and within the recommended limits below:
Performance restricted
restricted by drainage at
the rainfall intensities shown
bmt (mm)
minimum radius*
lowest neutral radius
370 mm/hr
220 mm/hr
150 mm/hr
0.42
70*
132
105
177
259
0.48
60*
132
105
177
259
*At these radii a maximum support spacing of 1200mm applies, and limit state pressure capacities are reduced by 14% for serviceability and 7% for strength. These reductions apply proportionately up to the lowest neutral radius.
Thermal Expansion
All metal roof sheeting is subject to thermal expansion and, where there is a temperature difference between the sheeting and the structure, this needs to be accommodated. The colour of the sheeting will affect the amount of thermal expansion, and whether the sheet is flat or curved will affect its ability to resist without problems.
Sheet lengths should be limited to those shown below.
roof colour
light
dark
flat
25
17
spring-curved
20
17
Water Carrying
Stramit Monoclad® cladding has excellent water-carrying capacity enabling roof slopes to be as low as 2° 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.
Photographs
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