If you have a roof leak and you're lucky, you'll be able to see water dripping from a hole in the attic roof, or light shining through the hole. In either case, insert a long wire up through the hole so that you or your roof contractor can easily find and fix the problem on the roof itself. For a temporary fix, you can apply a layer of roof patching compound on the underside of the attic.

Water can travel a long way before dripping into the attic, however. In this case, a nail driven through the roof where the drip is coming down will give you a clue once you're on the roof; look for the leak farther up the roof from where the nail comes through. (Always seal the nail hole with roofing cement once you've finished the repair.)

If you can't fix a leak right away, place a tarp over the damaged roof area, and nail it into place with strips of lath. Seal all the nail holes with roof cement once you've fixed the roof.

To fix a small damaged or blistered area on a flat roof, brush away the surface gravel and cut away the damaged section of the roof covering. Apply roofing cement or patch compound under the cut edges and to the patch area. Cover with a patch (check for patch kits at home centers) that's at least 2 inches larger on all sides than the damaged area. Apply another layer of cement, let it dry, and then brush the surface gravel back over.

Repairing Roof Flashing

Flashing is the name for the wide metal strips that you'll see sealing the joint wherever two materials meet on the roof-against the chimney or vents, or where two roof slopes connect. To reseal flashing, lift the shingles that overlap it, and cover about 6 inches of the flashing with roofing cement or patch compound. Replace the shingles, pressing them firmly into the cement.

For chimney flashing, caulk the seal between the chimney and the top of the flashing (remove any old caulking first), and the seal between the bottom of the chimney flashing and the edge of the roof flashing.

You can seal small holes in flashing with caulk or sealant, or with roofing cement and a flashing patch, or with an automotive fiberglass repair kit, but larger areas of damage mean that the flashing should be replaced.

Replacing Shingles

Loose asphalt shingles can be glued into place with roofing cement or nailed (use galvanized nails), with the nail heads sealed with roofing cement. A few curled edges of shingles can also be glued down with roofing cement, but be aware that curling edges are a warning sign that the shingles need to be replaced.

If you can't lift up the overlapping shingle to insert the pry bar, slide a hacksaw blade up under the damaged shingle, and cut through the nails that are holding it to the roof.

You can temporarily fix a torn asphalt shingle by nailing the sides of the tear down and covering it with roofing cement, or by cementing a piece of sheet metal under the shingle-but it's not difficult to actually replace the shingle.

Lift up the bottom edge of the shingle that overlaps the damaged shingle, and use a pry bar to remove the nails holding the damaged shingle in place. Remove the damaged shingle. If the new shingle is self-adhesive, position it and peel away the backing. If it's not, apply a layer of roofing cement to the bottom of the new shingle, slide the top edge into place, and then nail it down. Cover the nail heads with roofing cement, and also seal the edges of the shingles that overlap the new shingle.

Replace wood shingles as you would wall shingles (described in the previous section), remembering to leave a ⅛-inch expansion gap around the new shingle.

Many of the techniques described in this chapter, such as repairing concrete, can also be used to handle repairs in your yard. Detached garages and sheds also make good subjects for practicing your repair skills, because they're not on view the same way your house is, and the consequences of making a mistake are much less severe. Chapter 8 focuses on your yard-so stick around, outside the house.