The trees growing alongside your home provide additional shade from the heat of summer. However, if you're not having those trees trimmed, they could also be destroying your asphalt roof. In fact, the branches that extend over your roof can damage it in two ways.
The granules on your asphalt shingles help protect your roof from sun and weather damage. As your roof ages, it's not uncommon for granules to become loose and fall off. However, a good asphalt roof should last approximately 15–20 years.
Unfortunately, your asphalt shingles may not last that long if your tree branches make contact with your roof. Untrimmed branches can easily scrape across your shingles when moved by the wind. As they scrape across your shingles, the granules are loosened and begin to fall off. Without the granules to protect your roof, it won't last as long, and you'll have to replace it much sooner.
It's also important to keep in mind that branches hanging over your roof can break during a storm, causing serious damage.
The shade your trees provide might seem like a good thing and, for the most part, it is. However, when the branches of your trees extend over your roofline, some bad things can happen, one of which is roof rot.
The shade your trees provide, combined with organic debris like leaves and twigs, creates the perfect environment for roof rot to develop. The decaying debris, combined with the moisture from rain and humidity, allows moss and algae to thrive on your asphalt shingles.
Both algae and moss act like sponges, holding on to excess moisture. As these plants grow and expand, they push themselves underneath your shingles. No longer protected by the shingles, the underlying wood structure of your roof is now exposed to these water logged plants. As a result, the underlying wood, like the deck and the beams, will begin to rot.
Roof rot is a serious danger and can cause your entire roof to collapse if it is allowed to continue. The only remedy for this problem is to remove and replace all of the rotten wood as well as the shingles. That's an expense you don't want to incur.
Because untrimmed trees pose such a danger to your roof, you should have them trimmed regularly, such as by Trees Unlimited. By having your trees cut back away from your roof, you'll still be able to enjoy the shade your trees provide without the added risk of roof damage.