Roof damage can go deeper than shingles
Q. I had a tree limb fall on my roof, but I could not see any damage to the shingles. There wasn’t a leak in the last rains, but when I went into the attic I found some of the rafters were pulled loose. I have a walk-in attic and where two roofs come together — the roofer called it a valley — I could see that almost all the nails were pulled out of the ends of the other rafters. The roofer said I needed a carpenter, but I can’t afford both the new roof plus all the repairs, and it all has to be done at the same time. I’m afraid the roof might fall in on the house. Is there something I can do until I can save enough to have it fixed?
A. A roof valley is formed when two pitched rooflines meet at a 90-degree angle. When you are in the attic, the main rafter that all the shorter rafters are attached to is called the valley rafter.
This is where you saw the nails pulled loose because the force of the falling tree limb moved the main valley rafter. What you can do is brace the valley, without trying to move it, until you can have it replaced. Find the mid-length of the valley rafter and measure the distance from the underside of the rafter at that point to the top of the ceiling joists; add 12 inches to the measurement. Use this measurement to make a T-brace.
Make the brace by nailing two 2-by-4-inch studs together to form a T. I like to use 16-penny cement coated nails that really grip the wood, making it hard to pull apart. Locate a bearing wall under the valley where you can place the brace. Do not place the brace on a ceiling joist or you could damage the ceiling below. A bearing wall can be found where the ceiling joists cross one another end to end and are attached to the top of the wall plate. A bearing wall is generally, but not always, found in the middle of the home. If you can’t find a bearing wall near the valley rafter, you can make a trough to lie on top of the ceiling joists to spread the weight of the brace and valley rafter over a larger area. Nail a 2-by-10-inch board to the side of a 2-by-6-inch board to form an L-shaped trough that my crew used to call a “hog trough.”
The trough should be about eight to ten feet in length. Lay the trough on top of the ceiling joists with the 2-by-10-inch board pointing up and the 2-by-6-inch laying flat. Make sure the trough does not cover any electrical wiring. Secure the trough to the ceiling joists using several two and one-half inch long No. 8 wood screws.
Do not nail the trough to the ceiling joists or you might damage the ceiling or the fixtures below. Cut the T-brace to fit at a slight angle and hammer in place. Secure the brace at the top and bottom using 8-penny nails. Check the brace occasionally because the roof rafters move slightly during high winds, snow accumulation and the changing humidity levels in the attic.
Ÿ Dwight Barnett is a certified master inspector with the American Society of Home Inspectors. Write to him with home improvement questions at d.Barnett@insightbb.com.
Scripps Howard News Service