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Fix-It-Yourself Project #108
"How to Apply Asphalt Shingles"

Tool and Material Checklist

Shingles, Hammer, Carpenter's apron, #15 felt roofing, Ridge shingles, Asphalt Roofing cement, Copper or aluminum flashing material, Soft soled shoes, Level, Clean-up cloth, Roofing nails, Chalk line, #90 mineral surface roofing, Tin snips, Ladder, Work gloves, Safety rope, Hand cleaner

1. Important Points to Remember

Working on any roof can be dangerous. You should take every safety precaution and use extreme care while working on the roof. Use common sense while working on the roof. Let someone know you are up there, or better yet, work with a helper.

Use a ladder that is high enough and strong enough for the job you are doing. Make sure the ladder is secured at the top and bottom before climbing it. Don't touch power lines, conduits or TV antennas. Never let a metal ladder come in contact with them. Never start a roofing job in cold or wet weather. Don't walk on a roof before the early morning dew has disappeared.

Wear heavy rubber-soled shoes with a non-skid tread to prevent slips, and avoid wearing loose clothing. If the roof slopes more than a 6" rise for every 12" horizontal, use roof brackets and boards to provide extra footing support. Place all tools and shingles where they will not slide from the roof. Keep the roof surface clean and free from loose nails and shingles. They can cause you to slip and fall. Keep people away from the area below where you will be working.

2. Determining the Materials Needed

Roofing shingles are sold by the "square". Most asphalt shingles are baled with three bundles per square. First, measure the length and width of each area of the roof, and then total the results to obtain the total square feet of shingles needed. Don't forget to measure any dormers or extension. Divide the results by 100, and buy that many squares of shingles. It's a good idea to add 10% for cutting, waste and starter courses, and to save one bundle for possible future repairs.

You'll also need approximately 2-1/2 pounds of roofing nails for each square of shingles. Use hot galvanized roofing nails, either 11 or 12 gauge with a 3/8" diameter head, or follow the shingle manufacturer's recommendation regarding the type of nails to be used. Use 1-1/4" or 1-1/2" nails for new work, or 1-3/4" nails for reroofing or repairs.

If you are starting a new roofing job, or complete reroofing project, you'll also need enough rolls of 15 pound roofing felt to cover the roof area underneath the shingles. Roofing cement will be needed for edges, flashings and ridges.

3. Selecting the Shingles

There are many types, styles and sizes of asphalt shingles. A few of the more common types are shown in.

Start your selection process with the type and grade of asphalt shingle for the type of building. Some factors to consider are purpose of the building; the slope of the roof; local weather conditions; and the design, style and size of the structure. The exposure for each type of shingle is usually specified by the manufacturer. However, for most common shingles, a 5" exposure is standard.

4. Before you Begin

Asphalt shingles can be laid successfully over any existing roof. However, if more than three layers of old roofing are on the structure, they should be removed completely before applying new shingles.

If any repairs are necessary to the roof structure, they should be made before reroofing begins. Nail down or remove any loose or protruding nails. Renail any loose shingles, and replace any missing shingles with new ones. If applying new shingles over old wood shingles, nail them securely and use feathering strip if a smooth appearance is desired.

5. How to Replace Damaged Shingles

Making repairs to an existing asphalt shingle roof is simple. Just follow the step-by-step instructions here. Use a small pry bar to pry up the nails holding a damaged shingle. Remove both the nails and the shingle. If necessary, use a sharp linoleum knife to cut away a damaged shingle to remove the nails.

Always try to replace the damaged shingle with ones similar in weight, size and color. Apply asphalt roofing cement to the back of the replacement shingle before putting it into place. After positioning the new shingle, nail it down with 1-3/4" roofing nails. Try to position the roofing nails so they will be covered by the shingle above. For extra protection against leaks, apply a small amount of roofing cement to the nail head.

6. Shingling Roof Valleys

A valley is formed where two roofs join at an angle. Care should be taken when shingling in this area to prevent leaks from developing. Valleys should be covered with a mineral surfaced roll roofing material.

First, lay an 18" wide strip of the mineral roofing down in the center of the valley, from the eaves to the top of the ridge.

Nail it down on the outer edges only, making sure that the material stays flat in the valley. Place roofing cement along each edge of this strip. Next, place a 365" wide strip of the roofing material down on top of the previous strip, nailing it down on the outer edges.

Snap two chalk line down the edge of they valley. Start at the ridge, with the lines centered in the valley and 6" apart. As they go down the roof, spread the lines apart, approximately 1/8" per foot, down to the eaves. When applying the shingles, lay them down to the edge of these chalk lines, and cut to fit. Place the end of each shingle in roofing cement to seal them, and nail down. Do not nail shingles closer than 6" to the chalk lines.

7. How to Apply New Asphalt Shingles

Application of new asphalt shingles in a complete reroofing job, or on new construction requires a layer of 15 pound roofing felt applied over 5/8" plywood sheathing. Each course of the roofing felt underlayment should overlap the preceding course by at least 2" to provide adequate weatherproofing protection.

The felt underlayment should be stapled into position, starting at the edge of the eaves, and extending up to the ridge of the roof.

8. Starting the Shingles

First locate the exact center of the roof, and mark it with a chalk line. Next, install a starter strip along the bottom edge of the roof. Many manufacturers make a special starter strip, however, shingles may be turned upside down to form a starter strip. The starter strip should project out over the eaves and gable end approximately 5/8".

After the starter strip has been laid, again locate the exact center of the roof and mark it with a chalk line. Center this first shingle on the chalk line, directly on top of the starter strip, and nail it into position. Four nails should be used in each shingle. Always drive the nails straight in, never at an angle, as they might cut the shingle and cause leaks.

Place the nails about 5-5/8" up from the bottom of the shingle. Butt each succeeding shingle up against the center shingle, and continue applying shingles out to the end of the roof in each direction.

9. Installing Additional Courses of Shingles

After the first course of shingles has been laid on top of the starter strip, snap down a chalk line at the manufacturer's specified exposure, usually 5", to aid in applying shingles. Continue snapping down chalk lines until you reach the ridge of the roof. This will simplify the laying of each succeeding course of shingles in a straight line.

Now, start the second course of shingles on top of the first course by placing the cut-out over the center of the middle tab on the center shingle. Remember, a shingle cut-out must never come over another cut-out in the row immediately below.

Continue placing shingles in the second course out to the end of the roof in each direction. Start at the center of the roof for the third course of shingles. Again, place the cut-out over the center tab on the preceding row, and continue to the end of the roof.

Follow this procedure of applying shingles until you reach the ridge of the roof. Then start on the other side of the roof, following the above instructions.

10. Shingling Vent Pipes

Mineral surfaced roofing material or metal flashing should be placed around the vent pipe before shingles are laid. Cut a square of flashing material with at least 6" of edge around the vent pipe. Cut a hole in the center large enough to fit over the vent pipe. Coat the bottom side with roofing cement, slip it over the vent pipe and nail it in place.

Lay shingle up to the vent pipe, covering the edge of the flashing material. Set ends of shingles in roofing cement. Cut a hole in the next shingle to go over the vent pipe, apply roofing cement to the bottom, and nail it in position.

Repeat the procedure on the next course of shingles that may overlap the vent pipe.

11. Shingling Around Chimneys

Mineral surfaced roofing material or aluminum flashing should be placed around the edge of a chimney before shingles are positioned. On old roofs, use the old flashings for a pattern. Fit the new flashing around the base of the chimney. Cement and nail this flashing in place.

Cut flashing strips in pieces 7" x 10", bend in half to 7" x 5". Place these flashing strips against the chimney, seal with roofing cement, and nail into place. Apply shingles up to the edge of the chimney, seal the edge with roofing cement, and nail near the edge of the flashings.

12. Shingling Hip Roofs

Each course of shingles applied to the hip roof should be continued around the roof. Each shingle should be trimmed to the angle of the hip ridge. Use regular hip shingles or cut standard shingles (three-cut), to cover the hip ridge. The hip ridge should be covered before the main roof ridge.

Start at the eave, and apply hip shingles at the same exposure as the main roof. Use two shingles to start the run on the hip ridge. Use four nails per shingle, leaving no nails exposed. When placing the last hip shingle on the main ridge, seal it with roofing cement, and nail it in place.