C purlins

C purlin 100x50x20 mm has a 100 mm web, two 50 mm flanges and two 20 mm lips. The lips turn inward at the flange edges and stiffen them. GBTL also makes C purlin 120x50x20 mm, which has a deeper 120 mm web.

Use a C purlin for single spans, edge and eave members, framing around openings and back to back double members. For long continuous roof runs, Z purlins that overlap at the supports are often more efficient. GBTL makes C purlins in 100 mm and 120 mm web depths for solar and roof structures in Bangladesh.

GBTL supplies C purlin 100x50x20 mm in 2.0 or 2.5 mm and C purlin 120x50x20 mm in 2.5 mm for solar structures. The right thickness depends on span, loads and purlin spacing, so take it from the structural design. Standard C purlin orders start at 2 MT.

GBTL offers hot dip galvanizing on C purlins on request, to ISO 1461. For 2.0 to 2.5 mm steel, the ISO 1461 minimum mean coating is 55 micron. GBTL targets 85 micron on C purlins, confirmed per section thickness on quote. Coastal sites in Bangladesh can fall in ISO 9223 category C4 or C5, with first year zinc loss of 2.1 to 8.4 micron.