How to Add Reinforced Roof Collar Ties

Adding reinforced collar ties to your roof's rafter system helps maintain its strength and avoid sagging between the peak and the eaves. This is especially important in older homes; homes in heavy snow areas, and homes that have multiple layers of roofing materials. Collar ties are simply horizontal boards nailed to the rafters to form an additional structural connection, which increases the amount of weight each rafter can carry. If your roof is already sagging significantly, consult with a structural engineer or expert contractor because your roof may need more than simple collar ties for reinforcement.

2-inch-by6-inch lumber
Measuring tape
Saw
Hammer
2-1/2 inch (8 penny) nails

Instructions

- 1
  Go into the attic and take measurements to estimate how much lumber you'll need. Collar ties are generally located halfway to three-quarters of the way up the rafters toward the peak. Measure the distance between adjacent rafters and use whole pieces of lumber. To really strengthen the roof system, add double collar ties on every other rafter. Buy a few extra pieces of lumber.
- 2
  Start installing collar ties at the gable end wall. Cut the first piece of 2-inch-by-6-inch lumber to length. You may angle the ends to approximately match the pitch of your roof, but you don't have to. Nail the collar tie in place. Hint: Start nailing on the ground by driving the nails partway into the end of the board, and have a helper hold the other end of the board in place as you nail onto the rafter face.
- 3
  Continue to measure and install additional collar ties across each pair of rafters. If you're adding double collar ties, put the other one on the opposite side to sandwich the rafters in between the extra support.

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