Roof washing treats the dark streaks, algae and moss growing on shingle roofs with gentle, low-force methods in place of a pressure washer. Rob, a Woodstock family man working without subcontractors, washes roofs in Lakewood, IL, where shade from mature trees and lake humidity keep slopes damp. Roof washing starts from $250. Text roof photos to (815) 451-0106 and the quote is free.
A dark streak down a shingle roof looks like dirt, but it is a living thing. The usual cause is Gloeocapsa magna, a cyanobacteria that spreads in a damp climate and darkens as it grows. Some shingles contain limestone filler it can feed on, and any roof collects the organic film it also lives on. The streaks begin on the slopes that stay shaded and wet.
That describes a lot of Lakewood. Large lots, tall trees, lake moisture and open space mean many roofs here spend the morning in shade and the evening under a canopy of leaves. This page is a decision guide: when roof washing helps, when it does not, and how Rob handles a shingle roof so the cleaning does not hurt it.
Which slopes darken first on a Lakewood house
Look at the north-facing slope, the section under an overhanging oak, and the valley where two roof planes meet. Those are the places where leaves collect, dampness lingers and sunlight rarely arrives to dry things out. Streaks usually start there and spread downhill.
A roof next to the lake or a wetland edge tends to stay damp longer after dawn fog or humid nights. That is not a defect in the roof, only the nature of the site. It does mean that a neighbor across the village with an open lot may have a cleaner roof of the same age.
Decision guide: wash it, watch it, or call a roofer
Go ahead and wash when the shingles are sound and the trouble sits on the surface, such as streaks, light algae or thin moss along the edges. Cleaning slows further damage and brightens the house. Watch it if the streaks are faint and the roof is in good shape, since a light film is mostly cosmetic.
Call a roofer first if shingles are curling, cracked, missing granules down to the mat, or lifting at the edges. Cleaning will not repair those problems, and Rob will say so. An aging roof near the end of its service is a replacement discussion, not a washing one.
- Wash: dark streaks on sound shingles
- Watch: light film on a newer roof
- Roofer first: curling, cracking or bare patches
- Roofer first: active leaks in the attic
Why a pressure washer is a bad idea on shingles
Shingle makers and trade groups caution against blasting asphalt shingles with a pressure washer. It can blast off the granules that shield the shingle from sun and force water under the edges. Once that protective layer is gone, the roof ages faster than it would have with the streaks.
The approach Rob uses is low pressure with a cleaning solution that kills the growth, followed by a gentle rinse. The detail is in the guide on roof washing and shingles, and a longer explanation of the streaks lives in the black streaks guide.
Moss, debris and what trees leave behind
Where trees overhang, a roof collects needles, twigs, seeds and a layer of rotting leaves. Moss takes hold in that mat, particularly on the shaded edges of shingles. Brushing and rinsing at low pressure lifts the debris, but moss that has rooted deeply may need a second pass.
Trimming back overhanging branches does more for a roof than any single cleaning. Rob can point out which limbs are shading the worst slopes, though branch removal is for a tree service. Clean gutters matter too, so gutter cleaning often pairs with a roof visit.
What to expect from a roof washing visit
Rob covers or wets landscaping, applies the solution to the shingles from the ground and safe roof access points, and lets it work. The streaks usually fade over the hours and days after the rinse rather than disappearing at once.
Expect a short conversation before any work. Rob looks at a photo of each slope, asks about the age of the roof and recent leaks, and tells you if washing is the right choice. If you also want the siding cleaned, soft washing covers the walls with the same gentle approach.
Roof Washing through the year in Lakewood
Spring
A good time for roof washing before humid summer weather lets algae spread. Check roof valleys for winter debris.
Summer
Dry, sunny stretches work well for treatment, though intense midday heat on dark shingles is avoided.
Fall
Wait for most leaves to drop on oak-heavy lots so the roof stays clean through winter.
Winter
Roof washing generally waits. Snow, ice and cold limit both safety and the way the solution works.
Getting a quote
A roof is expensive, and the goal is to get more life out of it without damaging it. If the shingles over your Lakewood home are streaked or mossy, text Rob photos of each slope at (815) 451-0106. He will tell you whether washing makes sense, which areas to watch, and when it is time to call a roofer instead. The conversation costs nothing, and you decide from there.