Fix Sagging Roof Line

A sagging roof line may original from the ceiling s horizontal rafters.

Fix sagging roof line.

Unfortunately most roof structural defects don t respond well to homeowner fixes and require professional evaluation and repair. Push up on the plywood until the foam is touching the underside of the roof decking. 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. Check the ceiling for sagging by attaching a string on one end of the beam and run it along the bottom edge of the beam.

To learn more about roofs and attics see these other blog posts. If the line does not continually follow the bottom of the beam and the bottom of the beam is below the line the beam is sagging. The first step is to the basement first. Then inspect the metal or plywood gusset plates.

Fortunately there are different ways to jack up a sagging roof. This gives your roofer a chance to inspect the flashing and roof underlayment for damage. Next place your piece of plywood and styrofoam foam side up against the damaged roof decking. This may be problematic in winter months but allowing the roof to continue to sag can lead to greater problems such as a cave in.

If your roof is sagging under the weight of too many shingles ideally all the shingles should be removed and a new set installed. You will need to remove the shingles and the old decking however which means there will be an exposed hole in the roof. That s how to fix a sagging roof. Using a flashlight inspect the rafters and decking in your attic especially in the areas where your roof is sagging.

Look for any kind of damage including rot cracks breaks and more. Move the jack in increments of one inch to allow for the roof to be able to move with it without cracking. The easiest way to straighten rafters is to jack them into position. Problems with and repairs to a sagging roof should be evaluated by professionals.

If the sagging roof is due to rotting or warping roof decking the repair will be much easier. Why is my roof sheathing sagging between the trusses. When the framing of the roof is put together quite frequently two of the ceiling rafters will be fixed together as this will create a much longer span.