Applying Roofing Shingles

When it's time to reshingle your roof, follow these instructions to make your shingle project safer, easier and professional looking.

Important Points to Remember:

• Working on any roof can be dangerous. You should take every safety precaution possible, and always 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. Secure the ladder at the top and bottom before climbing it.
• Use extreme caution when working near power lines, conduits or TV antennas. Never touch them or allow a metal ladder to come in contact with them.
• Never start a roofing job in cold or wet weather. Also, allow early morning dew to disappear before beginning your work.
• 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" horizontally, use roof brackets and boards to provide extra footing support. Place all tools and shingles within easy reach and where they will not slide off the roof.
• Keep the roof surface clean and free from loose nails and shingles. These can cause you to slip and fall.
• Keep people away from below the area where you will be working.
  

Determine the Materials Needed:

• Roofing shingles are sold in "squares." Most asphalt shingles are baled together with three or four bundles per square.
• First, measure the length and width of each area of the roof. For each area of the roof, multiply the length times the width. Then add the results for the total square feet of shingles needed. Measure all dormers and extensions.
• Divide the total square footage by 100, and purchase that many squares of shingles.
• Purchase an additional 10% of the number of shingles for cutting, waste and starter courses, and to save one bundle for future repairs.
• You'll also need about 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 for the type of nails to be used.
• Use 1 1/4" or 1 1/2" nails for new roofs, or 1 3/4" nails for reroofing or repairs.
• If you are starting a new roofing job, or a complete reroofing project, you'll also need enough 15-lb. roofing felt to cover the entire roof area underneath the shingles.
• You'll need roofing cement for edges, flashings and ridges.
  

Select the Shingles:
There are many types, styles and sizes of asphalt shingles. Your selection process should begin with the type and grade of asphalt shingle needed for the type of building. Some factors to consider are the 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.

Before You Begin:
You can successfully lay asphalt shingles over any existing roof. However, if there are more than three layers of old roofing on the structure, they must be removed completely before applying new shingles.
Make any necessary repairs to the roof structure before beginning the reroofing project.
Drive down or remove any loose or rotruding nails.
When you're applying new shingles over old wooden shingles, nail them securely and use feathering strips for a smooth appearance.

Applying Felt For Asphalt Shingles
Applying new asphalt shingles on a complete roofing job, or on new construction, requires a layer of 15-lb. roofing felt over 5/8" plywood sheathing.

Step 1. Each course of the roofing felt should overlap the preceding course by at least 2" to provide adequate weatherproofing protection.

Step 2. Staple the felt underlayment into position, starting at the edge of the eaves and extending up to the roof ridge.

Step 3. Install a Starter Strip: 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 offer a special starter strip; however, if you don't have this strip, you can cut the tabs off the shingles and use the shingles to form a starter strip.

Step 4. Starting the Shingles: The starter strip should project out over the eaves and the gable end by about 5/8". After the starter strip is in place, again locate the exact center of the roof and mark it with a chalk line. Center your first shingle on the chalk line - directly on top of the starter strip - and nail it into position (Fig. 4).

Step 5. Nailing the First Course of Shingles: Use four nails in each shingle, located in the position shown in Fig. 5. Always drive the nails straight in and never at an angle, as they could cut the shingle and cause leaks. Place the nails about 5 5/8" up from the bottom of the shingle. Each succeeding shingle should bump up against the center shingle. Continue applying the shingles to the end of the roof in each direction.

Step 6. Adding the Next 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 simplifies the job of laying each succeeding course of shingles in a straight line.

• Start the second course of shingles on top of the first course. Place the cut-out over the center of the middle tab on the center shingle. Continue placing shingles in the second course 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 until you reach the ridge of the roof. Then start on the other side of the roof in the same way you started the first side.



• Tip: A shingle cut-out must never fall directly over another cut-out in the row immediately below it.

Courtesy of the National Retail Hardware Association - www.nrha.org.