Part of the home buying process is getting an inspection to find anything wrong with the home that could be a red flag. However, the home inspection doesn't come until after you have made an offer and are somewhat committed to buying the home. There are some red flags that you can catch early on about a roof that will tell you if it is in good or bad shape:
It is not a huge problem to see one or two missing shingles if the remainder of the home's roof looks to be in great shape. However, a sagging roof is something that you need to be cautious of. A sag in a roof tells you that there is an issue with the wood underneath the shingles. There could be potential damage such as rotting wood that needs to be replaced.
Sagging roofs most likely have water damage somewhere in the home's attic, and on the extreme end, have the potential to collapse. If you can identify a sag by looking at the roof from the ground, you may be in for more than you bargained for by purchasing the home.
The roof may look great without any sagging, but moisture could be getting into the attic. There may be issues with flashing that has deteriorated over the years and caused water to find a way into the attic. There may also be shingles that have slightly lifted off from the roof and let water get behind them.
See if you can peek your head into the home's attic and look for moisture damage. The rafters will look a bit discolored from water stains, or there could be a texture change in parts of the ceiling. Odors caused by mold will also be easy to notice, even if you cannot see the damage yourself.
Moss & Algae
Moss and algae is a problem that will deteriorate shingles and just look bad overall. While the problem is usually caused by shaded parts of a roof that don't get enough sunlight, it can usually be fixed by installing a metal roof cap. It forces trace amounts of metal to flow over the roof and kill moss and algae each time it rains, which should keep a roof free of this pesky problem.
Are you moving forward with buying a home, even though there are some roof problems? Contact a local roofer to fix them for you right after you move in. Contact a company like Columbia Roofing Inc for more information and assistance.