Repair a Broken Roof Rafter: Assess and Choose Who Does It

A roof structure has many components that need to work together to keep wind and rain at bay. Roof rafters are major structural components that support the weight of the roof and spreads the load down to the walls and foundation below. When a rafter begins to fail, it is important to fix the problem quickly to prevent further damage. You can learn how to repair a broken roof rafter.

Symptoms of a Broken Rafter

Many homeowners have no idea they have a broken roof rafter. Unless they make regular inspections of their attic, the problem is not found for a long time. But, a broken rafter can cause problems with the roof itself. You may have a broken roof rafter if:

  • You have a sagging area in your roof deck
  • You have a leak coming through the roof deck
  • You have shingles starting to pull away from the roof

Think about a roof rafter. It is one of several lined up together. When they are all in good shape, the roof decking attached to them is straight and secure. That straight surface allows water to flow off without any problems.

When a rafter breaks below, that removes a section of support under the decking. This can cause sagging in the deck. A sag in that support layer offers the perfect place for water to slow down and accumulate. That can lead to water penetration and eventually leaks. The sagging deck also moves enough that the shingles secured to it can get loose and start to fall off.

What Can Break a Rafter

There are several ways rafters can break or be broken:

  • Heavy load of snow or ice
  • A person stepping too hard
  • Someone cutting through the rafter
  • A flaw in the wood
  • Wood damage due to pests

Assessing the Damage

How much damage has the broken rafter done to the roof? That is a critical question you need to answer before you learn how to repair a broken roof rafter. If the broken piece has cause problems with the roof structure, you need to address all the problems along with the repairs to the rafter.

Look at the roof above the broken rafter as well as the underside of the roof deck attached to the rafter. If there is any water penetration, you will see water stains on the deck. You may find loose or missing shingles above.

If the water penetration is extensive or you have a number of loose or missing shingles, you need to bring in a roofing contractor. The broken rafter has compromised the strength of the roof and you want a professional to get the roof back into shape.

Fixing the Rafter

Here is how to repair a broken roof rafter.

  1. Place a jack below the break and push the rafter up until it is level with the rafters next to it.
  2. Cut 2×4 wood in lengths at least 1 foot longer than the broken area. You can use full length boards for extra strength.
  3. Using construction adhesive on the long face of on board, secure it to one side of the rafter with the break at the center.
  4. Drive a couple of 4″ screws into the 2×4, far enough to penetrate the rafter, but not go out the other side.
  5. Do the same thing to the other side of the rafter with the other 2×4.
  6. Drive all screws through to secure the three pieces of wood into a single beam. Add more screws every 6 inches on either side.

You have just learned how to repair a broken roof rafter.