Your roof is your home’s most important protectant and when it sags, it can’t do its job correctly. There are several things that could cause a sagging roof and here, our roofing repair experts take you through how to rectify each situation. Here’s how to fix a sagging roof:
What you’ll need to fix a sagging roof:
- Steel “L” channel
- Bolts & washers
- Pneumatic nail gun
- Plywood gusset
- Measuring tape
- Lumbar strapping
Determining the Problem
- Determine where the sag is in your roof in relation to your attic.
- Grab a flashlight and head up to your attic to inspect your roof rafters and decking – specifically those where your roof is sagging.
- 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.
Fixing a Truss or Rafter
- To get your truss or rafter back into shape, you can use a steel “L” channel.
- First, use your drill to drill four holes in each side of the “L”.
- Next, use a chisel to remove any pieces of wood (such as splinters or broken scraps) that may get in the way of your repair.
- Mount the “L” channel onto the truss or rafter. (It’s easiest if you begin the mounting at the end that’s most difficult to access.)
- Using the holes you drilled, fasten the end of the channel to the truss or rafter using your bolts and washers.
- Once the end is in place, move the broken piece into position.
- Determine the gap between the channel and the truss or rafter and choose bolts that are 1 1/2″ – 2″ longer than the gap.
- Insert and tighten the two bottom bolts until the washers are flush with the channel.
- Then, tighten the bolt farthest from the crack or break until the other bolt head is about 1/4″ from the channel.
- After that, tighten the back bolt until it’s close against the channel. Then, tighten the front bolt until the back bolt is about 1/4″ from the channel.
- Continue tightening both bolts back and forth until the truss or rafter is securely against the “L” channel.
- Insert bolts into the rest of the holes in the channel and tighten.
- Once your truss or rafter is back into place, it’s a good idea to add additional support to the area.
Fixing a Gusset Plate
- First, remove the gusset plate that has partially or fully pulled away from the two pieces of wood.
- Because it’s nearly impossible to reinstall the plate, replace it with a 1/2″ plywood gusset.
- Use a pneumatic nail gun and nails to attach your gusset on both sides of the wood pieces.
- This should replace the strength of the original gusset plate.
Fixing Roof Decking
Damaged roof decking should be repaired by a professional, but you can create a temporary solution by following these steps:
- Measure the damaged area between your roof rafters or trusses.
- Cut a piece of 1/2 inch plywood that will cover the area.
- 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.
- Next, place your piece of plywood and Styrofoam foam-side-up against the damaged roof decking.
- Push up on the plywood until the foam is touching the underside of the roof decking.
- 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. That’s how to fix a sagging roof.
*Photo courtesy of ready2roof.com