Sistering joists is commonly used when adding onto an existing deck or repairing a deck.
How to sister roof joists.
In situations when sistering damaged floor joists with lumber of similar dimensions it can be easy to notch and slide the sister board into place.
Call in a structural engineer.
Measure the overall distance of the existing rafter from the ridge board to the outermost point where the rafter.
Fasten the sister joist to the existing joist with three nails every 16 in.
Run the rows parallel and an inch.
How to sister a roof rafter 1.
Nail 10d or 16d common nails through the sister and into the existing joist.
Nail the new joist in place.
You should overhang at least a couple of feet on each side of the beam.
Determine the angle of the.
The longer the overlap distance the stronger the connection.
Make two rows of nails spaced 16 inches or less apart along the length of the sister.
In these cases the overlapped joists help tie the framing together by combining the rigid members over a beam.
Take some extra time and jack the damaged area up so that the new lumber doesn t need to be.