Using I Joists For Roof Rafters

Usp994 131 usp connector guide for trus joist.

Using i joists for roof rafters.

All nails shown in the details above are assumed to be common nails unless otherwise noted. A framer s guide to the installation process. Photo 2 shows a view of the other ends of these same i joist rafters and the use of. The manufacturer would need to design the repair.

The diagram provided by bruce is an example of special requirements. When wood i joists are used as rafters connections at the structural ridge and the tops of exterior walls must be detailed properly. While typically not a problem when the roof is flat and the i joists bear perpendicularly on the top plate when the rafters are sloped proper bearing becomes an issue. These i joist rafters are on 24 inch 61 cm centers and support plywood roof sheathing and wood shingles.

I joists make for a strong flat roof but you have to pay attention to the connections at the ridge and eaves. 9030 floor framing standards guide. 10d box nails may be substituted for 8d common shown in details. Tj 9510 installation guide for floor and roof framing with tji s31 s33 and s47 joists east canada.

First they made i joist cross cutting jigs from osb scraps and made a few practice cuts. Use single i joist for loads up to 2000 plf double i joists for loads up to 4000 plf filler block not required. The one that is cut might be a problem. As a structural engineer i have inspected many roofs framed with i joist rafters but very few that have not needed a correction due to the i joist bearing.

Making top cuts in the i joists to make the short rafters one person held the tji down to the horses while another one made the cut. The first thing to understand is how a roof framed with wood i joists differs structurally from a tradi tional stick framed roof. In a typical roof framed with dimension lumber the rafters rest on the exterior wall top plate at the lower end and bear against a ridge board at the top. Attach i joist to top plate using 8d nails at 6 o c.