I Joists For Flat Roofs

This is the distance between joist centres.

I joists for flat roofs.

Villa truss we manufacture engineered open web floor and roof trusses for residential and commerical applications. Flat roofs usually come with a 10 to 20 year warranty but can last 25 years if you build the roofs right and maintain them using commonsense rules. I joists are comprised of top and bottom flanges which resist bending united with webs which provide outstanding shear resistance. Allowable spans for joists and rafters 1 7 lumber grade floor joists ceiling joists 5 rafter ceiling joist combination rafter ceiling joist combination rafters 6 douglas fir larch no 2 or better drywall below 2 no finish below 2 plaster below 2 drywall below 3 lightweight roofing.

I joists make for a strong flat roof but you have to pay attention to the connections at the ridge and eaves. When wood i joists are used as rafters connections at the structural ridge and the tops of exterior walls must be detailed properly. The roofing surface is installed over the joists while insulation is placed between them and the ceiling beneath is suspended from them. Usually 400 450 or 600mm but any value can be used up to 610mm max.

This demo version is fixed at 1m clear span. Flat roof joist calculator. Nail must provide 1 inch minimum penetration into floor joist. To build a roof joist for a flat roof you need some carpentry skills and a few basic tools.

Attach rim joist to top plate per 1a pri rim joist per 1a attach rim joist to floor joist with one nail at top and bottom. Plaster below 2 lightweight roofing. For 2 1 2 and 3 1 2 flange widths toe nails may be used. Minimum 1 3 4 bearing required attach i joist per 1b.

The full version allows any size. It is the responsibility of the designer of record to address items like ponding snow drift loads lateral loads wind loads bracing ventilation and insulation when adding a slope to roofs. We deliver to plate line in northern california. I joists are strong lightweight i shaped engineered wood structural members that meet demanding performance standards.

1 enter joist details 1 1 span and joist spacing. Drywall below 3 tile roofing.