Drive through any Houston-area neighborhood and you'll see an impressive mix of roofing materials — asphalt shingles, clay and concrete tile, standing-seam metal, cedar shake, and large flat commercial membranes. Each material has a different composition, porosity, and vulnerability, which means each requires a distinct cleaning approach. Using the wrong method on the wrong roof type can cause real damage, so here's how our professional roof cleaning team handles each one.
- Every roof material requires a specific pressure level and chemical formulation
- Asphalt shingles need low-pressure soft washing exclusively — never high pressure
- Tile, metal, and cedar each have unique vulnerabilities that require tailored solutions
- Flat commercial roofs require different treatment than sloped residential roofs
- Using the wrong method can void warranties or cause irreversible surface damage
Asphalt Shingles
The most common roof type across Houston, Pearland, and surrounding communities. Asphalt shingles are the most vulnerable to high pressure because of their granule layer, which is why we use exclusively soft wash chemical treatments — following ARMA (Asphalt Roofing Manufacturers Association) guidance — to kill algae and moss without disturbing that protective granule surface. Results become visible over 2–4 weeks as normal rainfall washes away the dead organic material.
Tile Roofs (Clay & Concrete)
Tile roofs are among the most durable roofing materials, but they're also porous, which means algae, lichen, and moss can take hold not just on the surface but between and beneath individual tiles. We use a slightly higher water volume — while remaining in the low-pressure range — to work cleaning solution into grout lines and the gaps between tiles, removing growth that a simple surface spray would miss. Extra care is taken to avoid cracking or dislodging individual tiles, which can be brittle in older installations.
Metal Roofs
Metal roofing — increasingly popular in the Houston area for its hurricane resistance and longevity — collects a different mix of grime: pollen, tree sap, oxidation, and mildew streaking, particularly around seams and fastener points. We use metal-safe cleaning solutions specifically formulated to avoid damaging protective coatings or accelerating oxidation, applying them with soft wash techniques to restore shine without scratching the finish.
Cedar Shake
Cedar shake requires the gentlest approach of any roofing material. Cedar is a natural wood product containing oils that protect it from moisture and rot; aggressive cleaning strips those oils and accelerates deterioration. We use ultra-low pressure combined with wood-specific treatments designed to remove algae and lichen without stripping the shake's natural protective qualities.
Flat and Low-Slope Commercial Roofs
Commercial flat roofs face a different set of challenges: standing water after heavy rain, debris accumulation, and algae or mold growth across large membrane surfaces. We clean these as part of our commercial cleaning services, using techniques suited to membrane, modified bitumen, or built-up roofing systems, which have very different tolerances than sloped residential shingles.
Quick Reference: Roof Type and Cleaning Approach
| Roof Type | Cleaning Method | Key Risk if Done Wrong |
|---|---|---|
| Asphalt shingle | Soft wash, low pressure only | Granule stripping, leaks, warranty voidance |
| Clay/concrete tile | Low-pressure soft wash, higher volume | Cracked or dislodged tiles |
| Metal | Soft wash, metal-safe chemicals | Coating damage, accelerated oxidation |
| Cedar shake | Ultra-low pressure, wood-specific solution | Stripped natural oils, accelerated rot |
| Flat/commercial membrane | Specialized commercial-grade treatment | Membrane damage, standing water issues |
Why the Right Approach Matters More Than Speed
Some cleaning companies use a single generic method across every roof type to save time, which is exactly how avoidable damage happens. Our technicians identify the roofing material before beginning work and select the pressure level, chemical dilution, and application technique specific to that surface — the same evaluation process we apply to every job across Pearland, Friendswood, and the greater Houston area.
Combining Roof Cleaning With Other Services
Because roof algae, gutter buildup, and siding grime tend to occur together, many customers combine roof cleaning with gutter cleaning and house washing in a single scheduled visit. Check our service packages for bundled pricing options that cover multiple exterior surfaces at once.
Frequently Asked Questions
How do I know what type of roof I have?
Most homeowners can identify their roof type visually, but if you're unsure, our technicians will confirm the material during your free estimate before recommending a cleaning approach.
Can any of these roof types be pressure washed with high pressure?
No — all residential roofing materials we service are cleaned exclusively with low-pressure soft washing. High pressure is reserved for hard, non-roofing surfaces like driveways and patios.
Do commercial flat roofs need cleaning as often as residential shingle roofs?
It depends on drainage and surrounding vegetation, but many commercial properties benefit from annual inspection and cleaning to prevent standing water and membrane degradation.
No matter your roof type, GreaseKleen has the experience and equipment to clean it safely. Get your free estimate or call (713) 575-7392.
