You’ve got a leak in the roof valley on your house. The roof valley is where two angles of the roof come together and form a valley. Whether you have a woven shingle roof, a tile roof, or a composite roof, the basic steps required to repair the leak will be the same. Below you will find a list of the tools you’ll need followed by a list of steps to take to fix a leak in a roof valley.
Step 1 - Locate the Leak
Climb into the rafter below the roof with a good flashlight and look around for any water intruding through the roof. This will usually occur at a seam between water barriers or in the valleys.
Step 2 - Tear Down
In order to stop the leak in your roof, you need to get to where the leak is occurring. This will require that you remove the shingles. Carefully remove the shingles from the whole area of the leak and extend it approximately three or four feet beyond the leaking area. Make a neat pile of the shingles that you will be able to continue using.
Step 3 - Cut Out the Old Water Barrier
At approximately one foot from the edge of the area you cleared of shingles, cut the existing damaged water barrier out. Toss this off the roof carefully.
Step 4 - Install New Water Barrier
Unroll the tar impregnated felt and cut it so that it overlaps the existing water barrier by three inches on each side. Slide this piece under the edges of the existing water barrier at the bottom. Staple this piece using one staple for every three inches along the edges and seams. Unroll another piece of the same width and work your way up the repair area, overlapping the previous piece by about six inches to prevent infiltration of water under the seams. Once the complete repair area has been covered, move back to the bottom and unroll a piece that covers the whole repair area, from side to side, overlapping the existing barrier completely. Each succeeding layer should overlap the previous layer by a minimum of six inches.
Step 5 - Replace the Shingles
Once the water barrier is in place, you need to replace the shingles. You will need to start at the bottom and work your way up to the top of the repair area. Make sure you duplicate the weave pattern of the existing roof. Replace cracked, broken or rotted shingles with the new ones you purchased. Use two roofing nails per shingle.
These instructions should now allow you to repair a leaking roof valley on a roof with woven shingles. This repair process is also the same for composition and tile roofs.