You may find that several are in need of straightening and that some of the sheathing must be replaced.
My roof is sagging.
However it is important to fix the rafters before doing any other work to the roof.
That s why most of the ridge sagging occurs in the center of the roof page top photo.
Sagging or low spots in a flat roof may be due to undersized or weakened roof joists or problems with the buildup layers beneath the exposed roofing.
Straighten out your old house s sagging roof and get rid of those cracks in the wall with these easy to follow steps.
Sagging roof lines can originate with the horizontal ceiling rafters.
If your home has converted from shingles to tile you may need to add structural bracing in your attic to hold the extra weight.
If your roof is sagging under the weight of too many shingles ideally all the shingles should be removed and a new set installed.
A bunch of different issues can potentially be at the root of your sagging roof problems.
Step 1 the first step is to the basement first.
Ice or snow buildup.
Too many layers of shingles this is why we never recommend adding new shingles over old ones improper design.
Another reason your roof may be sagging is because it can t handle the weight of the roofing material.
Why is my roof sagging.
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.
When the roof framing is assembled two ceiling rafters are often joined together to create a longer span.
The first step is to find out how many rafters are sagging and if anything else is damaged.
For example tile roofing weighs way more than your typical asphalt shingle roofing.
As the wall tops are pushed outwards at their center either the entire wall leans over or as the wall is held up at the building corners gable ends the wall center may break and bend over as in my photo above.
Also inspect the metal or plywood gusset plates used where your wood meets on a truss look for damage that includes cracks rot breaks and any other impairment.
Deflection is the immediate sag produced when an object is set on a structural member.
Grab a flashlight and head up to your attic to inspect your roof rafters and decking specifically those where your roof is sagging.
Fixing a truss or rafter.
If the sagging appears in the plane of the roof that is up and down between the ridge and the eave and from side to side the sagging is probably due to deflection and creep of the rafters themselves figures 8 and 9.
