Those black streaks running down your roof aren’t dirt and they won’t wash off in the rain. They’re algae, and left alone they hold moisture against your shingles and shorten the life of the roof. Next Mile Enterprises soft washes roofs across Houston, Cypress, Jersey Village, Katy, Tomball and Spring — no high pressure, no shingle damage.
Call 281-806-5233 or request a free estimate.
What Causes Black Streaks on Houston Roofs
It’s a blue-green algae called Gloeocapsa magma. It feeds on the limestone filler in asphalt shingles, and it thrives in exactly what Houston has year round: heat, humidity and shade. That’s why the streaks almost always show up worst on the north-facing slope and under tree cover.
Left long enough it holds damp against the shingle surface, and moss and lichen follow. Lichen is the one that actually digs in — it roots into the granules and takes shingle with it when it comes off.
Soft Washing vs. Pressure Washing — Why It Matters
Never let anyone put a pressure washer on your shingles. High pressure strips the protective granules off, and a roof that looks clean the day it’s done can shed years of life in one afternoon. It can also force water up under the shingles.
Soft washing uses low pressure and a cleaning solution that kills the algae at the root, then rinses. It’s the method the shingle manufacturers themselves recommend, and it lasts longer than blasting because the organism is actually dead rather than just knocked off.
What Roof Cleaning Costs in Houston
We price by roof size, pitch and how much growth is on it. A steep roof takes longer and is more work to move around safely, so it costs more than a low-slope roof of the same square footage.
You get the price confirmed on site before we start. If it doesn’t work for you, we pack up and you owe nothing.
How It Works
- Call or text with your address and rough roof size.
- We look at pitch, growth and access, then quote it.
- We protect landscaping and plants below the work area.
- Low-pressure application, dwell time, then a controlled rinse.
- Most single-family roofs are done in one visit.
Roof Cleaning Near You
We run Cypress, Jersey Village, Katy, Tomball and Spring most weeks, plus Northwest Houston, and we take work across the greater Houston metro. Call and we’ll tell you straight whether we can reach you.
Common Questions
Will soft washing damage my shingles?
No. That’s the entire reason to use it instead of a pressure washer. Low pressure means the granules stay where they belong.
Will it kill my plants?
We wet down and cover landscaping before we start and rinse it afterward. Tell us about anything delicate and we’ll work around it.
How long does it stay clean?
Usually a few years in Houston, depending on shade and tree cover. Heavily shaded north slopes come back soonest.
Do I need to be home?
No, as long as we have access to the roof and an outside water spigot.
Is this covered by my roof warranty?
Soft washing is the manufacturer-recommended method, so it generally is — but check your specific warranty. Pressure washing a shingle roof can void it.
Get Your Free Roof Cleaning Estimate in Houston
Tell us what you need and we’ll send a straight price — usually the same day. Prefer to talk? Call 281-806-5233.