Roof Soft Washing in Lake and McHenry County

The streaks are an algae called Gloeocapsa magma. It feeds on the limestone filler in asphalt shingles, spreads on the wind and starts on the north slope, where the roof stays damp longest. It is not dirt, so rain does not wash it away.

Moss grows where shade and debris keep a roof wet: the valleys, the north side and anywhere a tree hangs over. Its roots lift shingle edges and hold water against the roof. Lichen, the crusty gray-green patches, holds on even tighter.

Every roof is a soft wash. What changes from one roof to the next is the mix, how long it sits and how the crew gets to it.

• Asphalt shingle. The most common roof in the county. The solution goes on at low pressure, sits long enough to work, and the next rains finish the rinse. The Asphalt Roofing Manufacturers Association recommends this kind of low-pressure wash for algae on shingles.
• Cedar shake. A milder mix and a longer dwell, so the wood comes clean without being stripped.
• Slate, tile and stone. Cleaned from the edge and from ladders, never walked on, because these crack underfoot.
• Synthetic. Cleaned to the maker's instructions, which vary by brand. Tell us the brand if you know it.

High pressure blows the protective granules off asphalt shingles. Those granules shield the asphalt from the sun, and once they are gone the shingle ages fast. Pressure can also void a roof warranty, and on cedar it gouges the wood.

Every roof is a custom quote. The roof type matters most, then the size and pitch, how high it is and how much is growing. Pick your roof type on the quote page and Andrew calls you back with a firm number.

Many people book the roof together with a house wash, so the whole house matches when we leave.

Most roofs stay clean for several years. Roofs under big trees or facing a lake see growth sooner, and it always shows up first on the north slope. Keeping branches trimmed back from the roof slows it down more than anything else you can do.

Plants below the roofline are soaked with water before we start and rinsed again when we finish. All we need is a working spigot and a way into the yard. You do not need to be home, and we walk the property with you at the end if you are.