Fix Sagging Roof Between Trusses

You can simply have the old sheathing replaced with better material when it s time for new roofing.

Fix sagging roof between trusses.

If the roof sags between the rafters or trusses the most likely cause is sheathing that s too thin for the area it covers. Cut a piece of 1 2 inch plywood that will cover the area. The first one is the rated span in inches for roof sheathing the second number is for flooring and the stamp will be visible from inside the attic. Often the framing can be bolstered and beefed up internally but if the roofing material needs replacement anyway it may be best to tear off.

The free ends of the expander are bolted below mid span on a pair of sagged opposing rafters. The span between trusses exceeds rating of the sheathing each panel of plywood or osb has a grade stamp on one face like the example shown at below with two big numbers near the top. Driving nails into it might make it worse place the plywood and styrofoam side up against the damaged roof decking. 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.

From the inside there doesn t appear to be any water damage or rot. Any ideas on how to fix this. Half inch drywall can sag if it s hung under roof trusses that are spaced every 24 in. Multiple layers of shingles and new roofing material that s heavier than the roof was designed for can cause sagging even in a well constructed roof.

If so i bet the installers used 1 2 in. I was thinking about putting additional. Remedies for a sagging roof there are a number of remedies for traditional rafter style roof frames depending on the problem and its severity. Sagging roof lines can originate with the horizontal ceiling rafters.

If a roof dips in between rafters or trusses it s probably because the sheathing is too thin for the span. Our roof sags a little between the trusses near the peak on the west facing side of the house. When the roof framing is assembled two ceiling rafters are often joined together to create a longer span. This will give some added strength and take care of any cracks in the wood itself.

Measure the damaged area between your roof rafters or trusses. The fix here is to replace the thin sheathing with thicker sturdier sheathing. Drill holes in angle iron to keep the rafter from buckling again you will need to secure it with a piece of 1 2 inch angle iron. If your roof is sagging under the weight of too many shingles ideally all the shingles should be removed and a new set installed.

Drywall instead of 5 8 in. I suspect that the plywood used was cheap quality or too thin. After measuring the damaged area between your roof trusses or rafters cut a piece of 1 2 plywood that will cover the area. Glue a piece of 1 rigid styrofoam to the plywood.