What PSI to Use on House Siding
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The short answer
Vinyl siding: 1,500–2,200 PSI with a 25° nozzle. Painted wood: 1,200–1,500 PSI with a 40° nozzle. Brick: 1,500–2,000 PSI with a 25°, avoiding mortar joints. Fiber cement: 1,500 PSI max with a 40°. Always spray slightly downward and keep the wand 12+ inches out.
House Wash Detergent With Mildewcide
Dwell time and chemistry remove mildew; pressure just removes the stain.
Siding damage from pressure washing usually isn't a hole — it's water driven up behind the laps, into window seals, or under paint, where it causes problems months later. PSI matters, but angle and direction matter more.
| Siding | PSI | Nozzle | Notes |
|---|---|---|---|
| Vinyl | 1,500 – 2,200 | 25° | Spray downward, never upward under laps |
| Painted wood | 1,200 – 1,500 | 40° | Detergent does the work, not pressure |
| Fiber cement | 1,200 – 1,500 | 40° | Avoid seams and caulk lines |
| Brick | 1,500 – 2,000 | 25° | Keep off soft or crumbling mortar |
| Stucco | 1,200 – 1,500 | 40° | Low pressure only; stucco chips easily |
| Aluminum | 1,200 – 1,500 | 40° | Dents and oxidizes; soft wash is better |
The Method That Works
- 1Close windows, cover outlets and move furniture and plants away from the wall.
- 2Rinse the wall from the bottom up with plain water to wet the surface.
- 3Apply house-wash detergent with the black nozzle, bottom to top, and let it dwell 5–10 minutes.
- 4Rinse top down with the 25° or 40° nozzle, keeping the spray angled slightly downward.
- 5Work in 10-foot sections so detergent never dries.
- 6Rinse nearby plants and the foundation when you finish.
Frequently Asked Questions
- Is 2000 PSI too much for vinyl siding?
- No, 2,000 PSI with a 25° nozzle at 12+ inches is a normal vinyl setting. The risk isn't the PSI — it's holding the tip close or spraying upward under the laps.
- Can I pressure wash a two-story house from the ground?
- With a wand extension or telescoping lance, yes. Raw PSI doesn't add reach; length and nozzle angle do. Never spray upward at full pressure without checking where the water goes.
- What kills mildew on siding?
- A house wash containing a mildewcide, or a diluted bleach solution applied at low pressure with 5–10 minutes dwell time. Pressure alone removes the stain but not the spores.
The Gear We’d Buy
Everything referenced in this guide, in one place.
House Wash Detergent With Mildewcide
Top pickDwell time and chemistry remove mildew; pressure just removes the stain.
Typically $15 - $30
40 Degree White Nozzle
The safe tip for painted wood, fiber cement and everything near window seals.
Typically $8 - $15
Telescoping Extension Wand
Reaches upper siding from the ground so nobody holds a wand on a ladder.
Typically $80 - $180
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Key Takeaways
- Vinyl 1,500–2,200 PSI at 25°; painted wood and stucco much lower at 40°.
- Always angle the spray downward, never up under laps.
- Detergent with dwell time does the mildew work, not pressure.
- Work 10-foot sections so soap never dries on the wall.
Fix this next
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- Pressure Washer Soap Not Coming Out: 6 Reasons
Detergent won't siphon if you're using a high-pressure nozzle, the soap is too thick or the siphon tube is clogged. Here's how to get suds flowing again.
Reviewed by
The Lawn Tool Hub Test Bench
We buy, borrow and break lawn tools on our own yards — clay in the back, sand-cut Bermuda in the front — and write down what actually changed the result.
Keep reading
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How to Pressure Wash a Deck Without Damaging It
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Pressure Washer Soap Not Coming Out: 6 Reasons
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Top pick
House Wash Detergent With Mildewcide