SF-160 is a double-cell FRP box purlin 160 mm tall and 55 mm wide with 4 mm walls, weighing 3.60 kg per metre. It spans 5.2 m at 0.65 kPa and 4.1 m at 1.25 kPa basic wind pressure, for factory roofs with frames 4 – 5 m apart. A vinyl ester grade is available for strong chemical fumes.
| Item | SF-160 |
|---|---|
| Section | Box 160 × 55 mm, 4 mm walls, two cells |
| Weight | 3.60 kg/m (a 6 m length is about 21.6 kg) |
| Resin | Polyester; vinyl ester for strong chemicals |
| Fittings | 304 stainless L-brackets, bolts, sleeves, screws and end caps |
How far can SF-160 span?
| Basic wind pressure W0 | 0.65 kPa | 0.95 kPa | 1.25 kPa | 1.55 kPa | 1.85 kPa |
|---|---|---|---|---|---|
| Maximum rafter spacing | 5.2 m | 4.6 m | 4.1 m | 3.8 m | 3.6 m |
For plastic roof sheets or ASA/PVC roof tiles, purlin rows 660 mm apart, deflection limit L/200. The middle web stops the tall side walls from buckling.
Factories with 4 – 5 m frames
With 5 m frames SF-160 works at 0.65 kPa. At 0.95 – 1.55 kPa use SF-220, and at 1.85 kPa add a middle rafter. Use one size larger along eaves, corners and gables.
Chemical plants, plating shops and wastewater plants
Acid fumes, hydrogen sulphide and ammonia condense under the roof and corrode steel purlins far faster than outdoor air, and paint peels within a few years. Polyester FRP handles humidity, ammonia, salt and dilute acids. For stronger acids, alkalis or chlorine, ask for the vinyl ester grade and tell us the chemicals, their strength and the temperature under the roof. Hydrofluoric acid attacks glass fibre and needs special advice.
Frequently asked questions
What size is SF-160?
A double-cell FRP box 160 × 55 mm with 4 mm walls, 3.60 kg per metre.
What frame spacing suits SF-160?
Up to 5.2 m at 0.65 kPa, 4.6 m at 0.95 kPa, 4.1 m at 1.25 kPa, 3.8 m at 1.55 kPa and 3.6 m at 1.85 kPa basic wind pressure.
Which grade for a plating shop?
The vinyl ester grade, because acid fumes are too strong for standard polyester over the long term.
All six sizes with the full span table: FRP Composite Purlin – SF Series.
Contact: Santiago Import Export Co., Ltd, Vietnam. WhatsApp +84 935 391 495 (Mr. Quyen), hotline +84 965 437 316 (Mrs. Ly), email salessantiagoroofing@gmail.com.
Updated October 2026.
