Roof Repairs – How to Repair a Roof

Roof Repairs – How to Repair a Roof

Overview: Roof Repairs – Do It Yourself Instructions

A leaky roof can create some major structural damage if left unchecked. Minor roof repair could save you lots of money, if they done in time. For example, taking the time to repair a leak will save you some costly structural roof repairs.

Keeping your shingles in good repair is the first step in preventing roof leaks. Whether your shingles are asphalt, slate or wood, you can repair any damage and help keep your rafters, and the rooms below, dry.

But shingles are only one source of the problem. Flashing around chimneys and vents can also pull away causing water damage in the house.

Should a leak develop in your roof, find and repair the leak first, then tackle any asphalt or flashing problem to prevent further damage.

Locating and repairing leaks in a roof

Roof Repairs

If a wet spot appears on your ceiling, there’s a hole in your roof that needs repair. But finding that hole is not always an easy task. The hole may not be directly above the wet spot, and you’ll have to determine the water path before you can find the source of the leak.

If you have no access to an attic (so you can find the leak from under the roof), measure the distance from the wet spot on the ceiling to a side of the house. Then, on a dry and windless day, transpose that measurement to the roof. Search in a broad area around your pinpointed measurement to find the leak. Leaks are usually caused by loose, torn or missing shingles, and defective flashing.

If you have access to an attic, grab a flashlight and search out the leak during a rainfall. Start your search directly above the water mark on the ceiling then follow the rafters to find the source, since water tends to leak down the rafters before dropping off to the attic floor.

Drive some nails or a wire through the hole to give you an exterior marker for your outside roof repair work. Temporarily fill the hole with a caulking compound to help reduce water intake while you wait for a dry day to repair the hole.

Asphalt shingles repair


Cracked, torn or missing asphalt shingles can cause water damage in the rooms below. But with a little care, shingles can be replaced without the need for major roof repairs work.

A very small crack in the shingles can be filled with asphalt roofing cement, but with larger cracks or tears the shingle should be replaced.

You’ll first need to lift the shingle on top of the damaged one to get at the nail. With the top shingles raised slightly, pry up the nails holding the damaged shingle in place. Watch that you don’t damage the roofing paper under the nails. Remove the old shingle and put a new one in place, making sure the top of the new shingle fits under the bottom of the shingle on top. With the top shingle raised slightly, nail the new shingle in place using roofing nails. Place some asphalt cement over the head of the nails and let the top shingle fall back into place.

If you need to replace from several courses, the procedure is the same as above, but you must remember to align the lower edge of the new shingles with the lower edge of the existing course. The joints should be staggered to match the existing pattern.

Since asphalt shingles tend to be more pliable when warm, wait for a sunny, warm day to do your roof repair work. The shingles will then be more flexible, preventing further damage to surrounding shingles.

To replace a ridge shingle, nail down the bottom shingle at the four corners and cover the nail heads with roofing cement Apply cement to the back of the new ridge shingle and position it, making sure it overlaps the bottom shingle by about 7cm (3in). Nail in place and cover nail heads with cement.

Slate shingles repair

slate shingles for roof repair

If a slate shingle is cracked but is otherwise in good repair, fill the crack with roofing cement, smoothing the cement down with a putty knife.

Slate shingles crack easily, so exercise caution when working on a slate roof.

To replace a slate shingle, use a nail ripper to remove the nails. Hammer the nails from the inside of the house first, if possible, to give you a better grip with the nail ripper and to help prevent cracking of other shingles.

If you need to cut a shingle to fit, score the cut line with a glass cutter, then snap the shingle in two over a straight edge. Hold the shingle in place on the roof and mark the location of the two nail holes. Pre-drill nail holes in the shingle to prevent cracking.

Apply roofing cement to the exposed area of the roof and to the back of the new shingle. Put shingle in place and nail into predrilled holes. Cover the nail heads with roofing cement. That’s all for slate roof repairs.

Wood shingles repair

wood shingle repair

What about bad wood shingles in your roofing? Warping or splitting is the major cause of damage to wood shingles, which means you will need to replace rather than repair them.

Remove the damaged shingle by first splitting the shingle with a chisel and mallet to dislodge it from the nail heads. Since wood isn’t flexible you can’t lift the shingle on top to get at the nail heads. Take care not to split any surrounding shingles

Measure the space for a new shingle and cut the new shingle to fit, reducing the size by about 1 cm (3/8in) to allow for expansion of the shingle during wet weather.

Push the new shingle up against the nails left by the old one. Push hard enough to make a mark on the wood. Remove the shingle and cut slots where the existing nails will slide in. Make the slots deep enough so that when you push the shingle into place, the lower edge of the shingle will line up with the lower edge of shingles in the same course. Nail the new shingle in place gently, to prevent splitting. Countersink nail heads and cover with roofing cement.

Flat Roof Repair

flat-roof repair

A flat roof is comparatively easy to roof repairs, and leaks are usually easy to find; the damaged area in most cases will be directly above the water spot on the ceiling.

Flat roofs are covered with asphalt-coated felt paper. The paper is sometimes covered with gravel to protect the roof from the sun.

To repair a leak in this roof, you must first sweep the gravel away from the damaged spot. Don’t use a shovel, since it can cause further damage.

When the damaged area is exposed and clean, you can determine the type of repair needed.

To repair a blister, slice through the center of the blister — making sure not to cut through the bottom layer of paper — and expose the two flaps. Allow the blistered area to dry. Once dry, force roofing cement into the blister and nail both sides of the slice, using roofing nails. Cover the repair with a shingle patch and nail around the four sides of the patch. Cover nail heads with roofing cement. There will be no need to reapply the gravel.

A more extensively damaged area is best repaired by cutting away a square patch from the surrounding area. Make sure you cut only the top layer.

Apply roofing cement over the exposed area and try to force some of the cement under the paper around the sides of the cut. Apply a patch of roofing felt to fit the area and nail around the four sides. Cut a patch with a 7cm (3in) overlap to cover the repaired area. Apply roofing cement to the underside of the new patch and nail into place. Cover nail heads with roofing cement.

If your roof develops several leaks, it would be best to cover the entire roof surface with black asphalt roof paint. Make sure the surface is clean and free of gravel. Starting at the highest point of the roof (even flat roofs have a slight pitch for drainage), apply paint with a long-handled brush to sections no bigger than 2sq m (25sq ft) at a time.

Leave a Comment