I Joist Used As Roof Rafters

6 8 sloped bearing conditions.

I joist used as roof rafters.

Use 2 6 rafters if your roof will experience heavy snow or wind loads. I joists are used extensively in residential floor and roof framing. Can span over 18 for gable roofed shed. Should not be cut like near the b vent.

Looks like they can be used as rafters. With an 8 soffit your rafter without a ridge deduction is roughly 20 4 3 4. Just found this interesting. Bci joists are specially constructed i joists with flanges made from strong versa lam laminated veneer lumber with oriented stranded board webs and approved waterproof structural adhesives providing outstanding strength and durability.

There s no reason to used i joist with a 15 span. For hip roofs with the hip trusses running parallel to the cantilevered floor joists the i joist reinforcement requirements for a span of 26 ft. Pdf says to consult with specific manufacturer for design installation specs. I joists make for a strong flat roof but you have to pay attention to the connections at the ridge and eaves.

These i joist rafters are on 24 inch 61 cm centers and support plywood roof sheathing and wood shingles. Software weyerhaeuser offers an array of software packages to help you specify individual framing members create cut lists manage inventories even to help you design a complete structural frame. It is always better to have a large rafter rather than be concerned with a sagging roof. Syp 2 6 rafters at 24 o c.

They are ideal for long spans including continuous spans over intermediate supports. No solid sawn conventional lumber should be used as rim joist with i joist. Trus joist tji s31 s33 and s47 joists for use in eastern canada. Shall be permitted to be used.

Again put them closer together if you want to achieve a greater span. An spf rafter can span nearly 15 at the same dimensions. All you need is 22 2x10 s or 2x12 s. Insulation should be 1 inch from b vent.

Photo 2 shows a view of the other ends of these same i joist rafters and the use of. When wood i joists are used as rafters connections at the structural ridge and the tops of exterior walls must be detailed properly. Because i joists are straight and true it s easier for builders to avoid crowning and maintain a level framing surface.