Save those old shingles and number them for replacing later.
Old roof new roof joined rafters fix.
Then the beam or roof may sag.
With the roof rafter pair straightened clamp new mid span cross ties in place and then nail the tie ends to the rafters.
Notice the rafter spreader bolt.
If a roof has been re roofed with heavier roofing material than the original roof was engineered for.
Strengthening can occur when the middle rafters have too much load that threatens to break the beam.
However the trick to this process is to do it very slowly so it may take a few weeks before you get the rafter into a position where it is straight again.
Measure the dimensions of the old rafters beneath your roofing surface.
This project requires two parts.
Use a circular saw to cut two sets of new rafters from the same size wood by the same dimensions.
The new part of the roof system can be erected both above and below the old elements of the roof.
To avoid this there are additional pads on the connection phase with a base.
When repair is no longer an option the roof rafters must be replaced.
The easiest way to straighten rafters is to jack them into position.
Measure the damaged area between your roof rafters or trusses.
Use your tape measure to record the distance of both rafter legs.
Because driving nails up into the sheathing material will make things worse glue a piece of 1 inch rigid styrofoam to your piece of plywood.
First remove the rotten wood and then replace it with new rafters.
Move the jack in increments of one inch to allow for the roof to be able to move with it without cracking.
Remove two shingles to each side of the new valleys until you reach the bottom.
Wood rotting from the inside out compromises the structural integrity of the rafter.
Repeat the process for the joist beneath your old roof rafter.
High enough to give room to nail the mid span cross tie at the desired location.
Starting two courses higher than where the new ridge meets the old roof unseal the shingle tabs a thin flat bar or a joint taping knife works well and pop the nails of the overlying course.