This is the easiest problem to repair.
How to fix a sagging garage roof ridge.
Push up on the plywood until the foam is touching the underside of the roof decking.
Use your string line to determine how much the roof need to go up.
In many cases you ll need to fix sagging trusses or rafters to repair your roof.
If you notice that there is a visible dip in your roof chances are you have a problem with one or several rafters and you may soon be facing more issues like water leaks bowed out walls or your roof caving in on you.
Not enough structural support for the load.
Rotten or saturated sheathing can also cause roof lines to sag.
If you have just stepped outside your house and realized that your roof is no longer straight this could signal a problem.
That s how to fix a sagging roof.
In some cases roof sagging problems are not caused by framing issues.
After that use a piece of lumbar strapping to keep the plywood in place until you can get a roofing repair expert to fix it.
Next place your piece of plywood and styrofoam foam side up against the damaged roof decking.
How to fix sagging roof trusses or rafters.
Fixing a sagging roof as soon as you spot it is very important otherwise you could find that the problem will only worsen over time and in the end you may need to have the entire roof replaced which could be extremely costly not to mention a lot of hassle.
You ll need a steel l channel to get your rafter or truss back into shape.
The cause of a sagging roof is straightforward in theory.
Sagging rafters can lead to serious problems with the entire roofing system.