How to Fix a Crack in an Attic Rafter

Adding a Scab

• 1

  Cut an 8-foot section of the same size lumber that the rafter is made of. For example, cut a 2-by-8 board if that is the lumber used on the rafters. This board is called a scab.

• 2

  Clamp the scab to the side of the cracked rafter. The scab should be positioned with the crack at the center.

• 3

  Drill pilot holes every 5 inches in a zigzag pattern through the scab and rafter. These holes should be slightly smaller than the diameter of the screws and will help prevent the wood from splitting.

• 4

  Screw the scab onto the cracked rafter with 3-inch wood screws.

Reinforcing the Rafter

• 5

  Cut two 2-by-6 boards long enough to extend from either side of the scab to the ceiling joist below.

• 6

  Clamp these braces to the broken rafter on either side of the scab. The other ends should be clamped to the ceiling joists.

• 7

  Drill four pilot holes per connection in a square formation and screw in four 3-inch wood screws.