In Southern Indiana climates a problem that occurs for many roofs in the area are moss, algae, lichens and fungus’. These organisms like to live in humid climates and shady areas. They love moisture and one place that they can get that moisture is on shingles. They also absorb and hold moisture on the roof causing the life span of the shingles to lessen quicker than should. Because we live in or around a lot of wooded areas and we have such a humid environment, these are very common problems homes have to deal with on the roof and attached to the house materials. Moss needs 3 things to grow, shade, humidity and moisture that makes for our area the perfect area for moss to grow. Especially on roofs.
In some circumstances the roof can be cleaned with bleach and water, being very gentle with the shingles so that they are not damaged and in some other cases the roof is better off being replaced than trying to clean it. Especially if you see that the shingles are weak, brittle, cracked or curled. You can always contact a roofing contractor to evaluate the condition of the shingles and help with a solution. The worst thing that can be done is to ignore the problem and let it become worse or to try a cleaning method that can damage the shingles. High Power washing the roof is not a fix plus it damages the shingles.
In some cases there can possibly be damage to the decking because the fact that the moss or algae obsorb moisture and hold it which can weigh down into the shingles to the sheeting. The moss and moisture can get under the shingles causing shingles to break away and become brittle then the decking becomes exposed to the moisture. In which you want to get that situation taken care of before damage can become worse but in most cases they just damage the shingles more than the roof. There isn’t a point of having a lifetime shingle for instance but have a severe case of moss or algae that makes the shingles last less than they should.
If you live in a wooded area and/or your roof is shaded most of the time in an area, you want to make sure you check into whether you have moss, algae, lichens or a fungus on the roof. If so there are some things that you can do to prevent it whether you have it or could develop it. Copper or zinc strips or flashing can help eliminate and prevent the growth of any of these. There are also shingles that are made resistant to these as well using granules on the shingles to prevent the growth. You might see some homes that have a copper/zinc strip on the ridge line of the roof or copper flashings.
These not only effect roofs but they can also attach to the home like vinyl siding, bricks, or wood. It is important to keep an eye out for any staining or growth anywhere on your home and tend to it if it develops. Especially if your roof tends to hold more moisture due to shaded area. Moss and algae may not grow on every roof that is in a wooded area, shaded area or moist area, but sometimes they do find a place to start spreading so there is no way to know if they will try to grow on yours or not but you can still prevent it from trying and if you do have any then you can eliminate it and prevent it from coming back. Keep your shingles in the condition they should be and lasting as long as they are supposed to by looking over your home and roof when you can.