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UpkeepPressure Washing

How often should I pressure wash my house?

Plan on washing the siding about once a year, and it does not have to be a pressure wash. CertainTeed recommends cleaning its siding once a year, and James Hardie suggests a garden-hose rinse every 6 to 12 months. Shaded, damp walls may need a second rinse; use the gentlest method your siding maker allows, every time.

Free to ask. Local shops send quotes, and you pay only when you book one.

By Kasra Taheri, Founder, LoclisPublished

Researched and drafted with AI, then checked claim by claim against the sources listed below before it was published. Prices and rules change; the dates beside each source say when it was last checked.

Step by step

Read when to stop and call a pro, further down this page, before you start.

  1. Step 1: Wash once a year

    Give the whole house a gentle wash each year, in spring once the pollen has fallen or in early fall.[1]

  2. Step 2: Pick a cool, cloudy day

    Wash on an overcast, mild day so cleaner does not dry on the siding before you rinse it.[4]

  3. Step 3: Rinse the sheltered spots

    Between washes, hose off walls under eaves and porch roofs that rain does not reach.[4]

  4. Step 4: Inspect twice a year

    In spring and fall, and after big storms, walk around the house looking for cracks, warping and gaps at windows and doors.[2]

  5. Step 5: Keep gutters clear

    Clean the gutters so they do not overflow and streak the walls below.[6]

  6. Step 6: Trim plants back

    Keep shrubs and branches cut back from the siding so the walls get air and sun and dry after rain.[7]

  7. Step 7: Spot-clean early

    Wash off a patch of mildew or algae with a mild siding cleaner and a soft brush as soon as you see it, rather than waiting for the yearly wash.[1]

  8. Step 8: Keep the pressure low

    Use a garden hose, a hose-end house wash or the widest, gentlest pressure washer nozzle, and only if your siding maker allows it.[2][5]

About once a year is the usual rhythm for washing a house, and the wash does not need much pressure. CertainTeed's advice for its siding is direct: "We recommend cleaning your siding once a year to avoid build up and keep it looking its best."[1] James Hardie gives a range for its fiber cement: "It's recommended to pull out the garden hose and douse your home siding every 6-12 months."[3] Shaded walls and sheltered corners may need a quick rinse in between.

The same white vinyl siding wall before and after a low-pressure wash: green streaks of growth on the left, clean panels on the right
Photo: East Coast Powerwashing, CC BY-SA 3.0, via Wikimedia Commons

Why once a year, and why gently

Rain does much of the work on open walls. Alside says that ordinarily the cleaning action of rainfall is enough to keep its siding clean,[4] with periodic rinsing with a garden hose and clear water particularly in those areas not exposed directly to rain.[4] A yearly wash removes the film of dirt and pollen that rain leaves behind before mildew and algae take hold on it.

More pressure more often is not better. CertainTeed's spring checklist warns: "Power washing can damage siding or cause water to seep behind panels."[2] James Hardie tells owners not to use a high-pressure power washer on its siding and trim, and to use a low-pressure hose and a soft, non-metal brush instead.[3] A yearly gentle wash is usually easier on the house than a hard blast every few years to strip built-up growth.

When to wash more often

Some houses need a second, smaller round:

  • Heavy shade or trees. Mildew is most common on walls behind trees or shrubs where air movement is restricted,[7] so wooded lots and shaded north walls grow back faster.
  • Sheltered spots. Porch ceilings, soffits and walls under deep eaves get no rain rinse at all.
  • After a messy season. A heavy pollen spring, nearby construction dust, or a summer of gutter overflow can leave a film that is worth rinsing off before it grows.
  • Before painting or staining. Paint needs a clean, dry surface.

Signs that it is time: a dull or chalky film that comes off on your hand, green or black spots on shaded walls, streaks below the gutters, or spider webs and debris collecting under the eaves.

When to wash less, or not at all

Not everything outside needs a regular wash. Brick, stone and stucco usually only need cleaning when they look dirty or start growing something. The EPA puts it plainly: "If your home was built before 1978, it is more likely to have lead-based paint."[8] Where the paint is chalking or peeling, do not pressure wash it on a schedule. Have a lead-safe certified contractor deal with it instead.

A simple yearly routine

Pick a mild, cloudy day. Alside recommends an overcast cool day (55-75 degrees), washing small areas at a time[4] so the cleaner stays wet until you rinse. Soak nearby plants, wash with a siding cleaner and a soft brush from the bottom up, and rinse from the top down. For the full method, nozzle and distance if you use a pressure washer, see how to pressure wash vinyl siding without damaging it. Stay on the ground; the Simpson pressure washer manual says: "Do not use pressure washer while standing on a ladder."[5]

Pair the wash with an inspection. CertainTeed suggests: "Schedule inspections twice a year (spring and fall) and also after major storms."[2] While you are washing: "Look for cracks, warping, or gaps—especially around windows and doors—to prevent moisture intrusion."[2]

Make each wash easier

Fewer washes start with drier walls. The EPA's moisture advice includes: "Clean and repair roof gutters regularly."[6] Cut shrubs back from the siding, turn sprinklers away from the house, and keep mulch from piling against the bottom course. If one wall keeps going green within months, find the water source; see why siding turns green.

Stop and call a pro if

  • The walls that need washing are above the first storey, or the job would mean getting on the roof.
  • The house was built before 1978 and the paint is chalking, cracking or peeling.
  • Your inspection finds cracked, loose or warped panels, gaps at windows, or soft trim.
  • Growth keeps coming back fast even after you have fixed gutters and cut back plants.

Getting help

If a yearly wash is more than you want to take on, compare doing it yourself and hiring someone and what it costs, browse pressure washing businesses, find exterior pros around Blacksburg, or read the other exterior answers. If your inspection turns up damage, describe the siding repair once and licensed local businesses will quote it.

Common questions

Is it bad to pressure wash a house every year?
Washing every year is what siding makers recommend; high pressure every year is the problem. Use a garden hose, a hose-end house wash or a pressure washer's widest, gentlest nozzle from a distance, and only where your siding maker allows it.
When is a good time of year to wash a house in Virginia?
Late spring, once the heavy pollen has fallen, or early fall before leaves drop. Pick a mild, overcast day; Alside suggests 55 to 75 degrees so cleaner does not dry on the siding.
Can I wash the windows at the same time?
Carefully. The Simpson pressure washer manual says to use caution when spraying windows, to use the white 40-degree nozzle and to stay at least 4 feet away. A soft brush and a hose rinse is gentler on glass, screens and window seals.
Do I need to wash a house that gets plenty of rain?
Rain does much of the work on exposed walls; Alside says rainfall will ordinarily be adequate. The places that need you are the sheltered ones: under eaves, porch ceilings and walls behind shrubs.
Should I wash before painting or staining?
Yes. Paint and stain need a clean, dry surface. On painted wood with mildew, the mildew has to be killed first or it grows through the new coat. On a pre-1978 house, treat any loose paint as possible lead paint and hire a lead-safe certified firm.

Sources

  1. [1] How to Clean Vinyl Siding, CertainTeed. Checked October 26, 2026.
  2. [2] Spring Cleaning Starts at the Top, CertainTeed. Checked October 26, 2026.
  3. [3] How to Clean Siding on Your House, James Hardie. Checked October 26, 2026.
  4. [4] The Care and Cleaning of Vinyl Siding, Soffit and Accessories (Alside Vinyl Siding Limited Warranty), Alside. Checked October 26, 2026.
  5. [5] Pressure Washer Use and Care Manual (part 7110656NOCA, rev. B, February 2026), Simpson Cleaning (FNA Group). Checked October 26, 2026.
  6. [6] A Brief Guide to Mold, Moisture and Your Home, U.S. Environmental Protection Agency. Checked October 26, 2026.
  7. [7] Discoloration of House Paint: Causes and Cures (NCR-134), Purdue University Cooperative Extension Service, with the USDA Forest Products Laboratory. Checked October 26, 2026.
  8. [8] Protect Your Family from Sources of Lead, U.S. Environmental Protection Agency. Checked October 26, 2026.

Want a pro to handle it?

Describe the job once. Licensed local businesses send quotes, and you pay only when you book one.