SF-220 is the largest Santiago FRP purlin, a double-cell box 220 mm tall and 55 mm wide with 4 mm walls, weighing 4.53 kg per metre. It spans 6.1 m at 0.95 kPa basic wind pressure, so 6 m factory frames can be roofed without a middle rafter in low-wind areas.
| Item | SF-220 |
|---|---|
| Section | Box 220 × 55 mm, 4 mm walls, two cells |
| Weight | 4.53 kg/m (a 6 m length is about 27 kg) |
| Resin | Polyester; vinyl ester for strong chemicals |
| Fittings | 304 stainless L-brackets, bolts, sleeves, screws and end caps |
How far can SF-220 span?
| Basic wind pressure W0 | 0.65 kPa | 0.95 kPa | 1.25 kPa | 1.55 kPa | 1.85 kPa |
|---|---|---|---|---|---|
| Maximum rafter spacing | 6.8 m | 6.1 m | 5.5 m | 5.0 m | 4.7 m |
For plastic roof sheets or ASA/PVC roof tiles, purlin rows 660 mm apart, deflection limit L/200. Spacing above 6.5 m needs its own calculation.
SF-220, or a middle rafter and a smaller purlin?
Price both before deciding. On 6 m frames at 0.95 kPa you can use SF-220 at 4.53 kg/m, or add a middle rafter so the spacing drops to 3 m and SF-120 at 2.36 kg/m is enough. The purlins then cost much less, but the extra rafter costs money too. Send the drawing and we will price both.
Why rust-free purlins on a large factory?
Replacing rusted steel purlins on a big roof means scaffolding, stopping production and often new sheets as well. SF-220 does not rust in salt air, ammonia or chemical fumes and is never repainted. Two people can carry a 6 m length, so no crane is needed on the roof.
Frequently asked questions
What size is SF-220?
A double-cell FRP box 220 × 55 mm with 4 mm walls, 4.53 kg per metre.
What frame spacing suits SF-220?
Up to 6.8 m at 0.65 kPa, 6.1 m at 0.95 kPa, 5.5 m at 1.25 kPa, 5.0 m at 1.55 kPa and 4.7 m at 1.85 kPa basic wind pressure.
Which FRP purlin for 6 m frames?
SF-220 up to 0.95 kPa. At higher wind pressure, or to save on purlins, add a middle rafter and use SF-120 or SF-160.
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.
