Common Pressure Washing Questions to Help Our Customers
If you offer pressure washing services or use a pressure washer regularly, you might run into common challenges. Here are answers to some of the most frequently asked questions to help you get the best results while protecting surfaces and equipment.
What PSI and GPM Should I Use for Different Surfaces?
The correct pressure (PSI – pounds per square inch) and water flow (GPM – gallons per minute) depend on the surface:
- Concrete driveways & patios – 2500-4000 PSI, 2-4 GPM
- Decking & wood fences – 500-1500 PSI, 1.5-2 GPM (use a fan tip)
- House siding & cladding – 1000-2500 PSI, 2-3 GPM (use a soft wash method for delicate surfaces)
- Roofs – 100-500 PSI (use soft washing instead of high pressure)
What’s the Best Nozzle for Pressure Washing?
Choosing the right nozzle is crucial to avoid damage:
- Red (0°) – Maximum pressure, not recommended for most surfaces.
- Yellow (15°) – Great for heavy-duty cleaning like concrete.
- Green (25°) – Ideal for general-purpose cleaning.
- White (40°) – Best for delicate surfaces like wood and siding.
- Black (Soap Nozzle – 65°) – Used for applying detergents.
For soft washing, use a wider-angle nozzle or a chemical injector for applying cleaning solutions.
Can I Use Regular Detergent in a Pressure Washer?
No! Always use pressure washer-approved detergents. Regular soaps and household cleaners can clog the system, damage seals, or harm surfaces. Choose biodegradable, eco-friendly cleaners designed for pressure washing.
How Do I Remove Stubborn Stains Like Oil, Rust, or Algae?
- Oil stains – Use a degreaser before pressure washing.
- Rust stains – Apply a rust remover and let it sit before rinsing.
- Algae & mould – Use a bleach-based or biocide cleaner with soft washing.
Pre-treating stains before pressure washing will give the best results.
Why Does My Pressure Washer Lose Pressure?
Common reasons for pressure loss include:
A clogged nozzle (clean it with a needle or nozzle cleaner).
Low water supply (check hoses and connections).
A worn-out pump or unloader valve (replace if necessary).
Air in the system (prime the pump by running water through it).
Regular maintenance prevents pressure issues.
How Can I Prevent Streaking or Striping on Surfaces?
- Maintain a consistent distance (usually 12-18 inches from the surface).
- Use overlapping strokes in a sweeping motion.
- Choose the correct nozzle and pressure for the surface.
- Avoid holding the spray in one spot too long.
Is Hot or Cold Water Better for Pressure Washing?
- Cold water – Works for general dirt, dust, and algae.
- Hot water – Better for grease, oil, and stubborn grime.
Power washers (with hot water) are great for commercial and industrial cleaning.
Can I Pressure Wash in Winter?
Yes, but take precautions:
- Avoid washing below 0°C (32°F) to prevent water freezing on surfaces.
- Use hot water if possible to speed up drying.
- Drain your pressure washer after use to prevent damage from freezing.
How Do I Maintain My Pressure Washer?
Regular maintenance includes:
Flushing the system after each use.
Checking hoses and fittings for leaks.
Replacing worn-out nozzles and O-rings.
Changing oil and cleaning filters on gas-powered models.
Proper care extends the life of your equipment.
How Can I Make My Pressure Washing Business Stand Out?
If you’re offering pressure washing services, here are some ways to stand out:
- Use before-and-after photos for marketing.
- Offer add-on services like soft washing, sealing, or gutter cleaning.
- Provide eco-friendly cleaning options.
- Maintain a professional image with branded gear and quality customer service.
