If a few shingles fall off your roof, you will probably call a roofing company and have them come to replace those shingles. Most people envision the roofing contractor climbing up on the roof and nailing some shingles over top of the empty patch. But that's not exactly what happens. Replacing missing shingles is more complicated than that, which is a big reason why it's always good to hire professionals to handle this task. Here are the steps your roof repair contractor will follow.

Step 1: Remove the nails and any bits of the shingle that are still attached.

Your roofer cannot replace just part of a shingle. They must replace the entire thing. So, if part of the missing shingle still remains on the roof, your roofer will pry it away. They'll also remove the nails that once held the old shingle in place.

Step 2: Lift the shingles under and next to the missing shingle.

Shingles are applied to the roof in a top-down manner. In other words, they overlap. The new shingle your roofer will attach will need to slide underneath the shingle below it, and it will also need to slide underneath the shingles on either its right or left, depending on how the original roofing company applied them. To allow the new shingle to slide properly into place, the roofing contractor will have to lift these other neighboring shingles. They may have to remove a couple of nails in the process.

Step 3: Slide the new shingle into place.

With the neighboring shingles loosened, your roofer will slide the new shingle into place. They will use a tape measure or a square to make sure it is even.

Step 4: Nail down the new shingle.

With the new shingle in place, the roofer will drive new nails into it. They will also replace any nails that they may have removed from neighboring shingles. If any of these nails are exposed, the heads will be covered in roofing cement to prevent leaks.

Step 5: Reseal the neighboring shingles.

The last step will be to seal all of the neighboring shingles back down so that water cannot slide between them and the new shingle. This is typically done with roofing cement or glue.

Now that you have a better idea of what is involved with replacing missing shingles, you'll understand why it takes a roofer more than a couple of minutes to make this repair. Contact a local roofing company for more information if your roof needs repairs.