Installing New Shingles Over Old Shingles
If you are looking to save time, installing new shingles over old shingles is a possible roof replacement solution. You want to be sure that you will be installing the shingles over only one other layer, though. The third layer of shingles will be too heavy to be supported. Re-roofing over old shingles can save you time and money since you will not have to rip off the old roof and pay to have it hauled away.
Step 1 — Seek Professional Advice
Contact your local government office to inquire about local codes regarding installing new shingles over old ones. Building codes in some areas will prevent this type of installation.
Step 2 — Inspect the Roof
You will need a ladder to climb up to your roof. Ensure that you are wearing proper footwear with a good grip to avoid injury or falling. Before you begin installing the new shingles, be sure to inspect the roof for any damage. Damaged shingles should be removed to check the decking for problems. Damaged decking will need to be repaired before you can install any new shingles.
Step 3 — Cover the Old Shingles
Install a layer of roofing felt over the roof before you begin installing the new shingles. The felt should be secured every six inches with nails or staples. The layers of felt should be overlapped by 1 inch as you work toward the roof ridge. This will help keep any moisture from getting under the felt. You may want to wear work gloves to avoid injuring your hand or developing blisters.
Step 4 — Prepare for the Shingle Installation
Use chalk line to mark a centerline down the roof from the ridge to the edge. Now you will need to determine the number of shingles required to cover the roof along the edge for this first row. Using a utility knife, remove the tabs from the shingles you will be using.
Step 5 — Lay the Trimmed Shingles
The first shingle should be centered over the line that you marked with chalk. The shingle should also hang about a quarter of an inch over the roof edge. Secure the shingle with nails one inch from each corner. The next shingle should be placed and secured beside the first one. Continue this until the first row of shingles is complete.
Step 6 — Prepare for the Uncut Shingles
Position one of the uncut shingles on top of a trimmed shingle. The uncut shingle should hang a quarter of an inch over the roof edge. Mark the location of the top of the uncut shingle on the felt. Use the chalk line to mark the line at that spot across the roof. Continue marking lines every five inches up to the roof ridge. Use the chalk to mark vertical lines from the center to the outside edge of the roof at six-inch intervals.
Step 7 — Lay the Uncut Shingles
Position a shingle with the first horizontal line. Secure the shingle with four nails. Two nails should be placed an inch over the tabs, and two more nails should be placed an inch from the top. Continue doing so until the first row of uncut shingles is complete.
Position the first shingle of the second row with the second horizontal line. Nail the second row of shingles using the same process as the first row. Continue laying all the shingles row by row until you reach the ridge of the roof.
This project would have taken up more of your precious time had you removed your old shingles first. Now you can enjoy your new roof, and rest assured that it will hold up until it is time to be replaced. Working on your roof can be dangerous, though. If at any time you begin to feel unsafe or unsure of what you are doing, there is nothing wrong with calling a contractor.