How to Install Shingles on the Roof

Putting shingles on a house is not the toughest job in the world if you are not too afraid of heights. Having no fear of heights is not necessarily a good thing because it might lead to careless behavior on a roof. Doing roofing work with shingles brings one of three circumstances. It may be a new construction with nice new decking to work from, it might be covering an old roof with a fresh layer of shingles, or it could require the removal of an old roof and start over from the decking up.

On any of the situations, the job is started by measuring the dimensions of the roof and determining the number of square feet of space to be covered. Once the length and width of each flat surface of the roof is known, each of these need to be multiplied together to get the number of square feet on each one. These totals need to be added together to get a final number of square feet.

For example, with a simple two-sided roof, measure the length and width of each side, compute the square feet and add the two numbers. This number needs to be divided by 100. This will give the number of squares of shingles that are needed. Roofers and material suppliers deal in squares or the number of hundreds of square feet on a roof. A house with 1,000 square feet of living space may very well require 12 to 15 squares of shingles to cover the roof surface.

Once the number of squares on the roof is known, it needs to be increased by about one square per major roof peak. This will make allowance for the ridge caps and starter shingle row. When ordering the shingles, it is best to inquire about how many bundles make up a square. Normally, this number is either 2 or 3, but it can vary depending on the exact type of shingles being bought. The supplier can assist with the proper number of roofing nails needed for the job. If the shingles will be going over an old roof, longer nails will be needed to pierce the entire thickness.

With shingles and nails in hand, it is time to get down to the business of putting on the roof. On new construction or after a previous set of shingles have been removed and hauled away, chalk lines need to placed across the roof at intervals that match the width of the shingles.

The first row of shingles is placed on backwards. That is, they are installed with the tabs pointing upward toward the peak of the roof. This row needs to be right against the edge of the eaves. The nails are put into the shingles at about 4 per shingle at the point where the strip of adhesive is on the back of the shingle.

Once the starter row is in place, the next layer of shingles is placed the right way right over the top of the first row. The final shingle on the row needs to be cut to match the edge of the roof. Some people prefer to cut these after the roof is completed, but most people find it is easier to cut-as-you-go. Most of the time the shingles will cut off on an even tab. It is a good idea to use the left over shingle to start the next row.

If the roof is being installed by a crew, instead of using the final leftover to start the next row, the starter shingle on the next row should have one tab removed to stagger the seam on the shingles.

The tabs should cover the entire upper portion of the previous row of shingles. This allows the finished job to have the characteristic look of many small shingles instead of long ones. Care needs to be taken to keep the slots on the shingles in straight rows unless some type of specialty shingle is being installed. Normally, row one is started with a full shingle, row two with a two-tabbed shingle, and row three with a single tab. This will make for a much tighter construction.

Keep up this procedure until the peak of the roof is reached. At that point, the upper edge of final row of shingles is lapped over the peak of the roof. The row needs to be cut off evenly along the ridge. When both sides of the roof are completed, enough shingles need to be cut into single tabs to allow the roof caps to be installed. The first tab is nailed in place with the bottom edge against the edge of the roof.

Just like the shingles, the next tab overlaps the upper part of the previous tab. The process is continued until the entire peak is covered. The final tab will be just the lower part of the shingle nailed over the last full tab to make all of the roof caps look the same.

To cover an existing roof, the same procedure is followed except that instead of making a chalk line, the lines of the old shingles are followed. The old roof caps must be removed before installing the new ones.