Frequently Asked Questions

These three terms get used interchangeably, but they're not the same thing.

Pressure washing uses high-pressure cold water — typically 1,500–3,000 PSI — to mechanically blast contaminants off hard surfaces like concrete driveways, sidewalks, and brick. It's appropriate for surfaces that can handle the force.

Power washing is the same as pressure washing, except the water is heated — usually to 200–250°F via a diesel or propane burner. Hot water breaks down grease and petroleum at the molecular level, making it the right choice for oil stains, dumpster pads, and commercial degreasing.

Soft washing is a low-pressure chemical cleaning method operating at 60–500 PSI — a fraction of pressure washing. The cleaning solution does the work, not the force. A professional-grade mix of sodium hypochlorite, water, and surfactant is applied at low pressure, allowed to dwell on the surface, and then rinsed. Soft washing kills organic growth — mold, mildew, algae, bacteria — at the cellular level, including spores embedded in porous surfaces that pressure washing can't reach. That's why soft-washed surfaces stay clean significantly longer.

Most residential exterior cleaning uses a combination: soft washing for siding, roofs, wood, and painted surfaces; pressure washing for concrete driveways and hardscaping.

Several common residential surfaces are damaged by high pressure and require soft washing instead:

• Asphalt shingle roofs — High pressure strips granules, breaks the adhesive seal between shingles, and voids manufacturer warranties. The Asphalt Roofing Manufacturers Association explicitly prohibits high-pressure washing on shingles.
• Vinyl siding — Pressure forces water behind lap joints and into wall cavities, causing hidden mold growth and wood rot.
• Painted brick — High pressure strips paint and erodes old mortar joints. On pre-1978 homes, this can blast lead paint into the air and soil.
• Wood siding and decking — Pressure splinters fibers, raises grain, and creates permanent washboard texture.
• Stucco and EIFS — Extremely fragile. Even moderate pressure damages the finish coat and forces water into the wall system.
• Windows — Direct high-pressure spray breaks thermal seals in double-pane glass, causing permanent fogging.

Yes, with proper technique. We pre-soak all plant beds, grass, and soil with clean water before applying any cleaning solution — hydrated plants absorb significantly less chemical than dry ones. We continue misting surrounding vegetation during cleaning and rinse thoroughly when the job is complete. We also use biodegradable cleaning solutions and apply a neutralizing rinse to deactivate any residual sodium hypochlorite before it contacts your landscaping. Downspouts are bagged during cleaning to prevent chemical-laden runoff from flowing into flower beds.

Yes, once dry. The cleaning solutions we use contain sodium hypochlorite — the same active ingredient in household bleach — diluted to professional cleaning concentrations. We ask that pets and children stay clear of the work area during cleaning and until surfaces are fully rinsed and dry. Once dry, surfaces are safe. We use biodegradable formulations and neutralize residual chemicals after every job.

A standard house wash on a single-family home takes 1–3 hours depending on size and condition. Driveway cleaning typically runs 1–2 hours. A combined house wash and driveway job usually takes 2–4 hours. Roof soft washing runs 1–2 hours for most residential roofs. Gutter cleaning takes 1–2 hours for a single-story home and 2–3 hours for two-story. We'll give you a time estimate when we confirm your appointment.

Green discoloration is almost always algae or mildew — biological growth feeding on moisture, pollen, and organic debris deposited on your siding. It establishes fastest on north-facing and shaded walls where limited sun exposure keeps the surface damp longer. Gray or chalky siding on vinyl is typically oxidation — UV degradation of the PVC material itself, not surface contamination. Soft washing removes biological growth; oxidation is a material condition that washing reveals rather than causes. Streaking on the exterior face of gutters is called tiger striping — a separate issue caused by overflow residue bonding to oxidized aluminum.

Soft washing will not damage intact paint. High-pressure washing absolutely can — and on painted brick, painted wood, or older surfaces, pressure washing is the wrong method entirely. Our soft wash approach uses low pressure and chemistry specifically to avoid paint damage. If paint is already peeling, bubbling, or failing, cleaning may accelerate what was already happening — we'll point that out during the estimate.

In Richmond's humid subtropical climate, annually at minimum. Most homes benefit from cleaning every 12–18 months. North-facing walls, homes under heavy tree canopy, and properties near water or in shaded settings may need cleaning more frequently — algae and mildew establish faster in those conditions. Late spring after pollen season is the most popular window, but exterior cleaning is effective year-round above freezing temperatures.

Oxidation is UV degradation of the PVC material — the chalky, dull, faded appearance on older vinyl siding, most visible on sun-facing elevations and darker colors. It's material degradation, not surface contamination, which means washing cannot remove it. What washing does is remove the dirt and biological growth that was sitting on top of the oxidized layer — which sometimes makes the oxidation more visible, not less. This is worth understanding before scheduling a house wash on older vinyl siding. We'll note any oxidation we see during the estimate.

It's Gloeocapsa magma — a cyanobacterium, not algae as commonly described. It feeds on the calcium carbonate limestone filler used in modern fiberglass asphalt shingles. The dark black color comes from a pigmented protective sheath each cell produces against UV exposure. Over time, the colony spreads downward across the roof surface. Left untreated, it loosens and detaches granules, reduces UV reflectivity, increases heat absorption in the attic, enables moss and lichen colonization, and significantly shortens roof lifespan. It spreads via airborne spores, which is why entire neighborhoods gradually develop the same streaking pattern.

Yes — significantly and permanently. The Asphalt Roofing Manufacturers Association (ARMA) explicitly states: "High pressure washing systems for algae removal should not be used." High pressure strips the ceramic-coated granules that provide UV protection, breaks the adhesive seal between shingles creating wind uplift vulnerability, and can void your manufacturer warranty. Major shingle manufacturers including Owens Corning, GAF, and CertainTeed recommend or require soft wash methods. Anything over 300 PSI is widely cited as enough to void asphalt shingle warranties.

We apply a professional cleaning solution — sodium hypochlorite at approximately 3% concentration, with surfactant added to help it cling to the roof slope — at low pressure from the ground using a dedicated soft wash pump system. The solution dwells on the surface for 15–30 minutes, killing Gloeocapsa magma and any other biological growth at the cellular level. The chemistry destroys the organism's cell walls, denatures its proteins, and eliminates embedded spores in the shingle pores — something water pressure alone cannot do. After treatment, natural rainfall rinses residual staining over subsequent weeks.

In Richmond's Mid-Atlantic climate, 3–5 years under typical conditions. Properties with heavy tree canopy, significant north-facing roof exposure, poor airflow, or debris accumulation in valleys may see regrowth sooner. For homeowners who want to protect that investment, an annual preventative treatment inhibits regrowth and keeps the roof consistently clean rather than waiting for visible streaking to return.

Yes. The black streaking is Gloeocapsa magma — a cyanobacterium. Moss is a true plant with root-like structures called rhizoids that physically anchor into and lift shingle surfaces. Moss holds 20–30 times its weight in water, which causes premature aging and water intrusion. It also requires a different treatment sequence: physical removal first where possible, followed by soft washing. Lichen — the round white, brown, or yellowish starburst spots — is the hardest rooftop organism to treat. It anchors into the shingle surface and cannot be removed by any pressure. The correct treatment is chemical application and waiting weeks to months for the dead growth to release on its own.

That's algae and biological growth feeding on organic material deposited by rain, pollen, and tree debris. Richmond's humidity keeps shaded concrete damp long enough for growth to establish quickly. Pressure washing alone dislodges surface growth but leaves spores in the concrete pores — they recolonize within weeks. Professional cleaning pre-treats with a sodium hypochlorite solution that kills growth at the cellular level before pressure washing, which is why results last significantly longer.

Depends on how deep the oil has penetrated. Fresh oil stains respond well to sodium hydroxide-based degreaser treatment — it saponifies the petroleum and allows it to be flushed away. Old, deeply embedded oil may lighten significantly but not disappear entirely. We'll give you an honest assessment during the estimate. For best results, treat oil spills as soon as possible.

Several possible sources. Rust stains — orange or reddish — typically come from fertilizer, metal furniture, or sprinkler heads hitting concrete. These respond to oxalic acid treatment. Brown staining in wooded areas is often tannin deposits from leaves and organic debris breaking down on the concrete surface — also treated with oxalic acid or post-treatment rinse. Reddish clay tracking is surface contamination that cleans off with standard pressure washing.

Done incorrectly, yes — permanently. Using a 0° or 15° nozzle tip, holding the wand too close, or staying in one spot removes the cream layer (the smooth cement paste on the surface), permanently exposing the aggregate underneath. Visible lines and pitting result. Professional cleaning uses 25° nozzles at correct working distance, a rotating surface cleaner for even coverage, and the circle technique to prevent striping. New concrete should not be pressure washed until at least 28 days after pour — before full cure, pressure washing damages the surface.

The correct sequence is clean → brighten → dry → stain. Cleaning removes biological growth and surface contamination using an oxygen bleach-based deck cleaner — not chlorine bleach, which leaves an unnatural whitewashed appearance on wood. Brightening with an oxalic acid-based solution immediately after cleaning neutralizes the alkaline cleaner, opens wood pores for stain penetration, restores the wood's natural color, and removes tannin staining. The wood must then dry for 48–72 hours minimum — below 15% moisture content — before stain is applied. Skipping the brightening step is the most common reason stain doesn't bond properly.

It depends on the manufacturer and the generation of composite. Current Trex high-performance lines tolerate up to 1,500 PSI with a fan tip. Early-generation Trex — Accents, Origins, Contours — should not be pressure washed at all; it will damage the surface and void the warranty. TimberTech allows pressure washing for rinsing only at maximum 1,500 PSI and prohibits cleaners with high pH. Composite decking cannot be sanded or refinished — damage is permanent. We check manufacturer guidelines for your specific decking before starting.

Wood decks annually, ideally in late spring or early summer. Composite decks every 12–18 months. In heavily shaded or humid settings, every 8–10 months may be appropriate — biological growth accumulates faster when the surface stays damp.

Pavers rely on a sand-filled joint system for structural interlock — there's no continuous slab. If high pressure blasts the joint sand out, the pavers become unstable and can shift. The recommended PSI for paver cleaning is 1,000–1,800 — significantly lower than the 2,500–3,000 PSI used on poured concrete. We use a rotary surface cleaner rather than a wand to distribute pressure evenly and avoid concentrated blasts into joints.

Efflorescence — a naturally occurring mineral deposit caused by moisture moving through the concrete and depositing calcium carbonate on the surface. It's most common on newer pavers in the first year after installation and typically resolves on its own as the concrete cures fully. It can be removed with mild acid washing but should not be sealed over — efflorescence trapped under sealer is permanent.

Sealing is optional but beneficial. It protects against staining, inhibits weed growth in joints, and extends the life of the clean appearance. There are two main options: wet-look sealers that darken and enhance color with a glossy finish, and natural-look sealers that are essentially invisible. The surface must be completely dry — 24–48 hours after cleaning — before sealing. Sealing over efflorescence or wet pavers causes permanent hazing and peeling. We don't offer sealing as a service currently, but we can advise on timing and product selection.

More than most homeowners expect. Water that can't move through the gutter backs up and overflows against the fascia board — the wooden trim behind the gutter. Fascia rot develops quickly from sustained moisture contact, and repair runs $6–$20 per linear foot. Overflow at the foundation creates hydrostatic pressure that forces moisture through concrete, and freeze-thaw cycles expand that trapped water and crack foundation walls. Foundation piering runs $7,500–$30,000. Ice dams form when clogged gutters prevent drainage, forcing water back under shingles. The damage compounds quietly and shows up as something expensive.

No. Gutter guards reduce frequency but don't eliminate the need. Fine debris — pine needles, shingle grit, pollen, seed pods — passes through most guard designs or accumulates on top of the guard itself. Annual inspection and cleaning is still recommended even with guards installed.

It depends on tree coverage. Minimal coverage: once per year in fall. Moderate coverage: spring and fall. Heavy coverage, especially pine: two to four times per year. After major storms: immediately. Richmond's mix of oak, maple, sweetgum, and pine creates significant seasonal debris — most homes benefit from at minimum two cleanings per year.

By surface type and square footage. House washing is priced by the square footage of the home's exterior. Driveway and concrete cleaning is priced by total square footage. Roof soft washing is priced by roof square footage and pitch. Gutter cleaning is priced by linear footage. We provide upfront pricing before any work begins — no surprises on the invoice.

Yes. Call (804) 764-0046 or fill out the quote form and we'll get back to you to schedule a free estimate.

Yes. Platypus Power Washing is licensed and insured in Virginia. We carry general liability insurance on every job and are happy to provide proof of insurance on request.