| Specification | SF-100 |
|---|---|
| Box section | 100 × 50 mm, wall 3.5 mm, 1 cell |
| Weight | 1.95 kg/m (about 11.7 kg per 6 m) |
| Max rafter spacing, W0 0.65 kPa (zone I) | 3.4 m |
| W0 0.95 kPa (zone II) | 2.9 m |
| W0 1.25 kPa (zone III) | 2.6 m |
| W0 1.55 kPa (zone IV) | 2.4 m |
| W0 1.85 kPa (zone V) | 2.2 m |
Spans are for plastic roof sheets or plastic roof tiles, purlins spaced at 660 mm, deflection limited to L/200.
Where is SF-100 used?
SF-100 is the size most used for poultry and pig farms, where rafters are usually 2.5 – 3 m apart. With 2.5 m rafters it works up to 1.25 kPa wind pressure; with 3 m rafters only at 0.65 kPa, otherwise use SF-120. Purlins along the eaves, corners and gable ends carry stronger wind suction, so use one size larger there.
Why should livestock farms stop using steel purlins?
Manure and urine release ammonia. Together with the humidity in the shed, it slowly eats the zinc coating of steel purlins, starting at the screw holes. Under ISO 9223, closed, humid livestock buildings are often rated C4, sometimes C5; at that level a Z275 zinc coating may last only about 2.5 – 9 years. FRP has no metal, so ammonia cannot make it rust, and no rust flakes fall into the feed. More: roofs for poultry and pig farms.
How is SF-100 delivered?
A 6 m length weighs about 11.7 kg, so one person can carry it onto the roof. Santiago FRP cuts it to the farm's rafter spacing, pre-drills the holes and supplies 304 stainless brackets, bolts, nuts, washers, anti-crush sleeves and self-drilling screws. Use stainless roofing screws too, so nothing on the roof can rust.
Frequently asked questions
What are the dimensions of SF-100?
SF-100 is an FRP box section 100 × 50 mm with a 3.5 mm wall, single cell, weighing 1.95 kg per metre.
What rafter spacing can SF-100 span?
With purlins at 660 mm under plastic roof sheets, SF-100 spans up to 3.4 m at 0.65 kPa, 2.9 m at 0.95 kPa, 2.6 m at 1.25 kPa, 2.4 m at 1.55 kPa and 2.2 m at 1.85 kPa basic wind pressure.
Can a pig farm with 3 m rafters use SF-100?
Only at a basic wind pressure of 0.65 kPa. At 0.95 – 1.25 kPa use SF-120, and at 1.55 – 1.85 kPa use SF-160.
Does SF-100 rust inside livestock buildings?
No. SF-100 is made of FRP composite and contains no metal, so ammonia and humidity in the shed cannot make it rust.