How To Extend Roof Joists

Rafters are placed on 24 centers and attached to the beams and settle joists are attached as needed image 1.

How to extend roof joists.

If the new sister bears on wood at least 1 5 on each end then you re good to go. The top chord smoothly extends out past the wall to create the overhang. If it is impossible to attach the ledger to a floor joist then fasten the ledger to wall studs which are generally located on 16 inch or sometimes 24 inch centers and doubled up around doors windows and other openings. If the roof slope is steeper than 9 inches in 12 inches of run it doesn t take much width to end up with a nice room 12 feet wide with an 8 foot.

Sistering or joining joists. The most common way joists are repaired is to sister it up. Temporarily nail or brace the ledger in place positioned and leveled at the desired height. That s a simple low cost solution that can tie in well with the main house.

Wood roof trusses bring the bottom chord of the truss all the way to the outside of the wall include a small vertical cut butt cut and angles back against the top chord of the truss. The sad fact is your builder could have installed attic trusses over this garage for just slightly more than what the existing trusses cost. The heel of the trusses are at the front of the house. Attach 2x6 rafters to the house with joist hangers and or supported by the ledger board.

If you re adding to the gable end of the house the side wall that goes up to the roof s peak it s fairly easy to extend the existing roofline over the new space says curt schultz a realtor architect builder in pasadena calif. Attic trusses have a rectangular shape inside each truss. Sistering joists is commonly used when adding onto an existing deck or repairing a deck. The term sistering joists is the practice of overlapping two joists by a certain distance across a beam to create an extended joist.

If you want to extend the rafters farther to cover a walkway or a porch. This is unusual in new deck construction and would only be necessary for very long spans that exceed the length of your longest boards. If the roof truss has a 2 4 top chord the heel is shorter than if it has a 2 6 top chord as a general rule. If necessary use a sliding bevel to determine angles needed where the rafters will meet the ledger board.