Detached garages are sometimes overlooked when it comes to roof replacements. This means your garage roof may be quite a bit older than the roof on your house. The following guide can help you make a decision if you suspect that it's time for a roof replacement.

#1: Perform an Interior Check

By their nature, many garages are damp and more open to the elements than a house, so it can be common for water to seep in under door sills. Your concern is for the water that leaks in through the roof. You will need to check for water damage, which appears as discoloration or mold growth, on the ceiling or exposed roof beams to verify that the roof is leaking. If your roof has a finished ceiling with storage or insulation above, peek inside to make sure water isn't leaking in. Wet insulation is a major clue that it's time to replace the roof.

#2: Let There Be Light

Take a stroll out to the garage after the sun rises. Once there, shut all the doors and windows. If necessary, tape black plastic over them so no light is leaking in. Now, look up. If you see light coming in through the roof, it's time to replace it.

#3: Check for Sag

If you notice sagging, either inside or on the exterior of the roof, the time to act is now. When the roof deck sags you will see the main support rafters protruding. A sagging roof deck is often caused by damaged underlayment boards or a broken rafter, and it can indicate that a collapse is imminent. Your best bet is to make the garage off limits until a roofer can replace the damaged boards or rafters and get a new roof on.

#4: Inspect the Shingles

A quick ground inspection can reveal if there are multiple missing or broken shingles. If the issue is just a few shingles, you may only need to replace these if the roof is in otherwise good condition. For a better view, get up on a ladder and lift up a couple of shingles. It's time to replace the roof if you find evidence of rot or mold beneath the shingles.

Unlike your home, detached garages don't usually have excessive flashing around chimneys and pipes that can cause leaks, so you don't need to inspect for flashing failure. Of course, a garage is also less likely to have gutters, so you won't be able to inspect the gutters for shingle gravel – another indication of a failing roof. Your best bet if you suspect your garage roof needs replacement is to consult with a roofing contractor like one from All American Roofing Incorporated.