Repairing damaged roofs

MATERIALS: Roofing cement, roofing nails, shingles

TOOLS: Ladder, claw hammer, caulking gun, flat pry bar, wood chisel, shingle puller, tool belt

If damage is limited, try short-term fixes by replacing shingles and applying roofing cement. Damaged or missing shingles are obvious; cracks or separated joints in the flashing can be harder to locate. When tracking the source of a leak, remember that water, having penetrated the roofing, often flows down the sheathing or, once through the sheathing, down a joist before finally dripping onto the ceiling below. Inside damage tells you nothing about outside entry. If you can get into the attic or crawlspace and if the roof joists are exposed, try to locate the actual entry point from below before going up on the roof. Use reference points, such as chimneys, ventilation pipes, windows, or valleys, to help you pinpoint the site once you’re on the roof. While you’re up there patching shingles that have already leaked, survey the roof for other problem areas.

Making Repairs With Roofing Cement

REATTACH BUCKLED SHINGLES WITH ROOFING CEMENT. Also use roofing cement to patch any cracks or other minor shingle problems.

REFRESH DETERIORATED ROOFING CEMENT AROUND FLASHING IF THE SEAL IS BAD. Joints around flashing or skylights are the most common places leaks can occur.

Replacing Asphalt Shingles

1 TEAR OFF THE UPPERMOST SHINGLE NEEDING REPAIR BY GRASPING THE SIDES AND WRIGGLING IT LOOSE. If you're replacing multiple shingles, start with the highest one. Remove all damaged shingles this way. Be careful not to damage surrounding shingles in good condition.

2 REMOVE OLD NAILS WITH A PRY BAR. If you cannot pry them out, drive the nails flat into the sheathing with a hammer. Patch any holes in the building paper with roofing cement.

3 INSTALL NEW SHINGLES ON LOWER COURSES following the normal shingle installation procedure shown on the bundle wrapper.

4 COAT THE TOP OF THE LAST SHINGLE above the seal line with roofing cement.

5 SLIP THE LAST SHINGLE INTO PLACE UNDER THE OVERLAPPING SHINGLE. Depending on the arrangement of the shingles, you may be able to drive a couple of nails into the shingle by gently lifting overlapping tabs of other shingles. If not, press the shingle down firmly to seat it in roofing cement.

Replacing Wooden Shakes

1 SPLIT THE DAMAGED SHINGLE WITH A HAMMER AND CHISEL AND REMOVE THE SHINGLE PIECES. Use a shingle puller to remove hidden nails. Slip the shingle puller under the shingle above, catch a nail, and hammer on the flat part of the handle to pull or cut the nail. Check the building paper for damage and repair or replace as necessary.

2 TRIM A NEW SHINGLE TO FIT, LEAVING ABOUT 3/8 INCH CLEARANCE ON EITHER SIDE FOR EXPANSION. Push the shingle in place until the lower edge is about an inch below the edge of the neighboring shingles. Drive nails into the top of the replacement shingle.

3 TAP THE BOTTOM EDGE OF THE SHINGLE, AS SHOWN, TO DRIVE IT INTO PLACE. The nails will bend slightly, hiding them under the shingle above. If the shingle splits when you try this, cut a new one, spread roofing cement on the upper half, and slide it in place under the shingle above.

Roof tear-off and repair

MATERIALS: Exterior-grade plywood, 2 1/2-inch galvanized screws, 8d ringshank nails

TOOLS: Roofing knife, flat pry bar, roofing shovel or pitchfork, circular saw, claw hammer, broom, drill and driver bit

DON’T GET RAINED OUT - When I was getting ready to tear off my old roof, I gathered all the equipment I needed, rounded up a couple of friends, and even rented a dump truck. If only I had checked the weather forecast, everything would have been perfect. My advice: Have a couple of tarps on hand in case of rain.

EAVE; The bottom edge of the roof.

HIP: A tine running from the eave to the ridge formed where two sloping sections of roof meet. Found on roofs with more than two main faces.

RAKE: The side edge of the roof, which runs from eave to ridge or hip.

RIDGE: The tine across the top of the roof, formed where two main faces of the roof meet.

VALLEY: A trough formed by two sections of roof meeting at an angle.

A new roof can go over an old roof. Depending on local code, it can even go over two layers of roof. Tearing off an old roof is hard work. Roofing materials start out heavy and seem to gain weight as the day goes on. Gathering the torn-up shingles once they hit the ground is even more work, so before you tear off the first shingle, borrow or rent a truck and park it under the eaves. Shovel the old shingles off the roof and directly into the truck. It will keep nails out of your lawn mower and your back out of traction. Find help if you can—this would be an excellent time to call in old favors. Before you let anybody on your roof, though, check your insurance coverage. And if the pitch of your roof is steep, make certain that each worker is secured by roofing jacks or a safety harness. Helpers who discover their fear of heights can still clean up and act as emergency “watchers.”

1 START AT THE TOP OF THE ROOF AND REMOVE THE OLD SHINGLES IN SECTIONS. Keep the roofing shovel (shown) or pitchfork tight against the plywood sheathing or lumber decking so that you can peel the shingles off in large chunks instead of individually. If you are saving your gutters, be careful not to ruin them during tear-off.

2 REMOVE FLASHING FROM ROOF VENTS, SKYLIGHTS, AND DORMERS. Some flashing such as that used on skylights is reusable. Chimneys should have two layers of flashing, some of which may be reusable. The rest, including the boot [a waterproof fitting) that goes around vent pipes, valley flashing, and dormer flashing should be removed and replaced. REMOVE THE SHINGLES ACROSS THE RIDGE. Remove the ridge with a pitchfork or roofing shovel last to protect the peak in case of rain.

3 PRY OUT ANY REMAINING NAILS. A ripping hammer with a flat claw like this one is specifically designed for pulling nails. Once you've pulled the nails, sweep the roof completely: It must be free of protruding nails and completely clean before you can move to the next step, which will be sheathing or shingling, depending on the roofing material you choose. Clean up stray nails from the yard using a release magnet, available at most rental centers.

Replacing Damaged Sheathing

1 SHEATHING CAN BE MADE OF EITHER PLYWOOD OR SOLID WOOD. While plywood is shown here, the procedure is the same for solid wood. Use the nail holes to help locate the rafters. Outline an area to cut out that is larger than the damaged area, cutting ends that are directly above the centers of the rafters. Set your circular saw to cut through the sheathing but not into the rafters, then make the cutout.

2 IF THE RAFTER IS SPLINTERED OR DETERIORATED BENEATH THE SHEATHING, screw or nail a 2x4 cleat to the side to provide a surface to attach the new sheathing. The new sheathing should be the same thickness as the old— generally 1/2-inch. In some areas 7/16-inch material is suitable as a replacement.

3 CUT NEW SHEATHING FROM EXTERIOR-GRADE PLYWOOD, MATCHING THE THICKNESS OF THE OLD SHEATHING. (Use solid wood to replace solid wood.) Cut the patch to allow a 1/8-inch expansion gap on each side. Nail the patch in place with galvanized 8d ringshank nails driven into the rafters and spaced 6 inches apart.

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