How to Install Shingles

With the proper know-how, you can install new shingles or replace old, bad ones on your roof. This article provides helpful information for all roofing projects, from minor repairs to full scale re-roofing.

Don't forget to take proper safety precautions. Always wear the proper safety gear and use a ladder with the proper height that is secured both at the top and bottom to prevent falls. Wearing the proper shoes will help you avoid slips as well, or you can also nail boards onto the roof for better footing. Take care not to make contact with power lines or other utilities, and only perform roofing work in warm, non-inclement weather.

Estimating Materials

Shingles are retailed in bundles called squares. To determine how many squares you'll need to buy to replace the damaged shingles, measure the total square footage of your roof. The dividend of the square footage by 100 equals the number of shingles required for a replacement. However, always buy extra material, just in case.

Home improvement stores also sell a variety of roofing nails which are specially designed for each type of shingle. While 1 1/2-inch nails are best for new roofs, 1 3/4-inch nails are reserved for repairs. You also need roofing felt and cement.

Selecting the Shingles

The type of shingle you purchase depends on several factors, including local climate, zoning codes, and the building's intended use. A sales associate at the home improvement can help you make the final selection; however, 5-inch exposure is the typical standard for replacing damaged shingles.

Preparation

You can have up to three layers of roofing material in place. If you have more than that, you must remove the existing material before applying the new material. Of course, you must also perform any repairs and handle loose nails.

Replacing Damaged Shingles

Pry out the nails to remove damaged shingles. If the nails are covered, use a knife to excise the shingle. Replace damaged shingles with new shingles that are similar in design to the originals and bond the shingle to the roof with cement and nails.

Roof Valleys

When repairing damaged shingles in an area where portions of the roof form an angle, you must take special care. Any mistakes could easily lead to leaks.

Apply roll roofing material to the valleys as illustrated. Then, add 18-inch metal flashing down to the middle of the
valley, securing it only to the exterior edges, and add cement. Place 36-inch roofing material over the original strip. Mark dual chalk lines, starting from the ridge with an initial spacing of six inches, and extend them outward from each other with increased spacing of 1/8-inch for every foot the lines extend.

Next lay the shingles as illustrated along the chalk lines. The shingles should not be laid any closer than six inches to the lines.

Asphalt Shingles

Use 15-pound roof felt and 5/8-inch plywood sheathing for asphalt shingles. Overlap each length of felt by two inches and staple to avoid damage from inclement weather.

Starting the Shingles

Snap a chalk line in the center of the roof. Then, attach a starter strip so that it extends from the roof by 1/2-inch at the lower tip. If you don't have a starter strip, refer to the figure to see how you can make you own from the shingles.

Apply the first shingle over the starter strip at the chalk line. Drive four nails into each shingle. Refer to the illustration of how to continue laying the shingles.

Adding More Shingle Courses

See the manufacturer's instructions for information about where to snap the chalk line for an extra course of shingles and make them until you reach the end. Lay the next row of shingles over the preceding one according to the instructions. Add the third course beginning in the center and repeat until the roof is complete.

Shingling Vent Pipes

You can use vent pipe boots when adding the final details around vent pipes. To make your own pipe boot, apply metal flashing with a six-inch edge to the vent pipe. Carve out a round shape in the center of the flashing that will wrap around the vent pipe, and put cement on the bottom. Add shingles until you reach the vent pipe; then cut out the center of the final shingle to fit it around the pipe.

Chimneys and Shingles

To re-shingle around a chimney, start by applying flashing just like you did for the vent pipes. Secure the flashing in place, then fold in half a 7x10-inch piece and place it against the chimney. Place these flashing strips against the chimney, seal the edge with roofing cement, and nail into place.

Shingling Hip Roofs

Hip roofs can take longer to shingle because every row on a hip roof must extend all the way around it. Shingles need to be cut and trimmed accordingly.

Start by placing the first shingle on the roof, making the bottom flush with the edge of the hip roof. Then, trim whichever side of the shingle rests against the angle of the hip roof ridge, matching the angle. For example, if you begin on the left, trim the left side of the shingle, and vice versa. The rest of the shingles continue to follow in the same fashion. Lay one row at a time and trim as you go.

Information Provided by the National Retail Hardware Association (NRHA)