Why does my roof have ugly black stains or streaks?
Generally speaking, black streaks on your roof are usually caused by an algae called Gloeocapsa Magma. The algae is a living organism that thrives by feeding on the roofing materials that protect your home.
They will generally make their home on the North side of your roof, as this is the area that delivers the optimum amount of shade and moisture, which the algae need to live and grow.
If left untreated, the damage caused by the algae can lead to a roof that needs to be totally replaced. Worse still, the algae can spread to other parts of the property, such as gutters, painted areas, and pavers, causing even more costly damage.
Is high pressure always the best option?
It all depends on the types of cleaners that contractors use. There are times when a high pressure washer in the hands of an untrained contractor can mean damage to your home. If the water finds its way under the siding, your home can develop mold and mildew problems.
Wood may seem strong, but looks are deceiving. It is soft enough to be subjected to pits and scars that develop when the water pressure breaks through the sealer.
The biggest mistake made is using pressure on asphalt shingles, as it can wash off the granules that coat the shingle. Those granules, that are similar to sand, add an extra layer of protection, and when they are washed away, the longevity of your roof can be compromised.
Always hire a contractor who understands the proper use of pressure.