The black (sometimes blue or green) stains commonly seen on roofs (known as gloeocapsa magma) is the common reason people ask us to clean their roofs. Most cleaners treat this as a mold, but gloeocapsa magma is actually a species of cyanobacteria. Cyanobacteria are an ancient line of photosynthesizing bacteria, which photolyze water, generating oxygen gas.
No matter what you define this as, it is unsightly and therefore affects the curb appeal of any home. The dark stains place an added load on air conditioning systems as well. As this bacteria feasts on the components of shingles, ultimately it invites moss and lichen and algae to infest the structure of the roof material and cause premature failure of the roof. It has been estimated that as much as 50% of all roof replacements have been done because of the appearance of the roof and not actually because of its functionality.
These stains are impossible to remove without the aid of chemicals. Caustics are inexpensive and very effective for killing molds like this.
Cleaning residential and commercial roofing has become one of the best profit centers of the exterior cleaning business over the last decade. This is due to two factors: the fast spread of the contributing algae problem from warm, humid climates in the southeast to the north and west; and secondly due to the touch-less cleaning techniques that came out of Florida over the last couple of decades.
We would show you causation and the wide array of solutions and techniques used to combat the problem. Just as in every other element of cleaning, there is no single way to achieve acceptable results – there are many ways to get the job done.
No matter how you end up cleaning roofs, there are basic things you should understand about roofs before you ever decide to tackle a job. If you are going to walk on a roof, for example, you had better know how that roof is constructed and where you can put your feet and still be safe. If a roof is close to failing due to age or abuse, you should be aware of that before you commit to do the work.
In our upcoming blog posts, we will start with discussing what is causing all of the problems and then move on to the most popular and profitable techniques used today.