| Specification | SF-80 |
|---|---|
| Box section | 80 × 40 mm, wall 3 mm, 1 cell |
| Weight | 1.33 kg/m (about 8 kg per 6 m) |
| Max rafter spacing, W0 0.65 kPa (zone I) | 2.5 m |
| W0 0.95 kPa (zone II) | 2.2 m |
| W0 1.25 kPa (zone III) | 2.0 m |
| W0 1.55 kPa (zone IV) | 1.8 m |
| W0 1.85 kPa (zone V) | 1.7 m |
Spans are for plastic roof sheets or plastic roof tiles, purlins spaced at 660 mm, deflection limited to L/200. W0 is the basic wind pressure of the Vietnamese wind zones I – V.
Where is SF-80 used?
SF-80 suits houses, small stores, small animal sheds and coastal fish stores with rafters 1.5 – 2 m apart. With 2 m rafters it works up to a wind pressure of 1.25 kPa; above that, use SF-100.
Why use SF-80 instead of steel near the sea?
Sea salt settles on steel purlins and starts rusting as soon as night dew dissolves it, especially in the gap between the roof sheet and the purlin. FRP contains no metal, so salt cannot make it rust. More on this: coastal roofs and corrosion.
How heavy is SF-80 and is it hard to fit?
A 6 m length of SF-80 weighs about 8 kg. Santiago FRP cuts it to length, pre-drills the holes, seals the cut ends and supplies 304 stainless brackets, bolts, nuts, washers and anti-crush sleeves, so no cutting or drilling is needed on the roof.
Frequently asked questions
What are the dimensions of SF-80?
SF-80 is an FRP box section 80 × 40 mm with a 3 mm wall, single cell, weighing 1.33 kg per metre.
What rafter spacing can SF-80 span?
With purlins at 660 mm under plastic roof sheets, SF-80 spans up to 2.5 m at 0.65 kPa, 2.2 m at 0.95 kPa, 2.0 m at 1.25 kPa, 1.8 m at 1.55 kPa and 1.7 m at 1.85 kPa basic wind pressure.
Can a seaside house with 2 m rafters use SF-80?
Yes, if the basic wind pressure is 1.25 kPa or less. At higher wind pressure, use SF-100.