Rafter ties another cause.
Sagging roof ridge beam.
Step 1 the first step is to the basement first.
The beam is attached to both exterior walls and to the bottom of each sloping rafter to give the roof strength.
Straighten out your old house s sagging roof and get rid of those cracks in the wall with these easy to follow steps.
Ridge beam or ridge board sagging or damaged roofs may sag because a ridge beam or ridge board is cracked or damaged.
This may have been caused by any number of factors.
If the beam is not properly nailed it can also pull loose and this contributes to.