4 Reasons You Should Never Pressure Wash Your House

By Scott Sidler August 31, 2015

never pressure wash your houseEverybody pressure washes their house. But few people know that the way it’s usually done is NOT good for your house.

You may just be going with the crowd, but in this case, the crowd is wrong, and you’re likely causing big damage that you have no idea about.

Pressure washing is usually the first step in getting a new paint job, so I see a lot of painters doing it and doing it wrong.

It’s not just unknowing homeowners doing this, it’s the professionals as well! Painters and pressure washing companies walk away from a house with a clean exterior, but the work they did has caused untold damage inside the walls of the house and other places.

There are four main reasons you should never pressure wash your house. Four ways that pressure washing does more harm than good. At the end, I’ll discuss the right way to way wash the outside of your house, but first the bad way.


Reasons to NOT Pressure Wash


#1 Water in the Walls

To me, this is the worst kind of damage you can do with a high pressure washer to a house. Commercial pressure washers shoot water at pressures starting at 1500 psi which isn’t too destructive, but they can go upwards of 3300 psi, which will blast through solid wood, asphalt, and even concrete (I’ve done it) if they’re close enough.

If you have a wood frame house with any kind of wood siding (clapboards, shiplap, board and batten, shingles, etc.) there is an excellent chance that washing your house with a high pressure washer will shoot water up under the siding, potentially soaking wall cavities, insulation, wiring, flooring, plaster, etc. Nothing is beyond the reach of these powerful water guns.

[Tweet “Your house is full of gaps and cracks and high pressure water will always find its way in.”]

Once the water is in the wall, it is often difficult for it to evaporate. Often, in the painting process, a house is pressure washed, then caulked and patched and finally painted. Essentially, the painter is soaking the inside of the walls and then sealing the water in with a fresh coat of caulk and paint.

I have seen moldy insulation, crumbling plaster, and cupped flooring all from a pressure washer’s work. Nothing in your walls likes to be wet so keep it dry.

#2 Missing Mortar

A lot of people think that since they have a brick house, they are safe to pressure wash. Think again! Old brick and mortar are softer than the new stuff today and can be easily blasted away with high pressure water.

I’ve seen brick houses with the mortar almost completely blasted away by pressure washing. And the expense of repointing a brick house is probably 10 times what the pressure washer charged you to wash your house.


#3 Gouged Wood

When pressure washing, a lot of painters will get right up close to the surface to try to blast loose paint off. They often succeed and then that 3000 psi water is blasting right into bare wood. It digs holes in the surface and furs the wood grain up damaging the siding.

Unless you’re into carving your name into the side of your house with water, this is yet another reason not to pressure wash.

#4 Lead Paint

It’s always there lurking beneath the surface on an old house. We all want it gone, but removing paint with high pressure water is not the solution.

It causes lead paint chips both small and large to be blasted all around the yard and get mixed into the soil where the kids can potential ingest it.

If you don’t have kids, think about the neighbors or the next folks. Lead paint is everyone’s responsibility. Read more about lead paint safety here.



When You Should Pressure Wash

Don’t think that I am against pressure washers. They are a great tool, I just see them being misused way too often. There are times and projects where a pressure washer is the best tool for the job and I want to be sure to mention those as well.

Some projects work best with high pressure (2000-3000 psi) and others with lower pressure (1250-2000 psi)

  • Decks (Low pressure)
  • Railings (Low pressure)
  • Wood Fences (Medium pressure)
  • Vinyl Fences (Medium pressure
  • Asphalt (Medium pressure)
  • Concrete Driveways & Sidewalks (High pressure)
  • Metal Patio Furniture (High pressure)
  • Stone and Pavers (High pressure)

So, if pressure washing is dangerous for your house what can you do to get things clean?


The Low Pressure Option

I’ve found that using a homeowner grade pressure washer allows me to safely wash a house with the pressure low enough to be relatively safe and I’ve outlined my methods in an earlier post Pressure Washing an Old House.

Ultimately, the safest way to clean and prep the exterior of your old home (especially wood houses) is to use a regular garden hose and spray nozzle along with an extension pole with a nylon scrub brush.

It takes longer, yes, but it actually does a better job at cleaning the house and preparing for paint in addition to being a hundred times safer for your house.

I’m not sure how many of you will follow this advice, but I would be remiss to not tell you the dangers. What you decide to do with the information is up to you!


Share Away!

84 thoughts on “4 Reasons You Should Never Pressure Wash Your House”

  1. Had house power washed by painter and left Windows a mess. Should he have cleaned or rinsed those . Never thought to ask

  2. Only one causing damage to a house is the guys not knowing what they are doing, pressure washing companies have moved to soft washing houses because of many reasons. It is still very safe to wash a house with no signs of damage being done. Just have to stop hiring those 99$ house wash guys ,

  3. This is great information! Thanks for sharing it. I live in a mobile home and was considering having it pressure-washed. Thanks to you, I now know better than to do that. Getting my elbow grease ready to go….

    1. So glad we could be of help and help preserve the integrity of your home! Have a great week!
      -Alyssa at The Craftsman Blog

  4. My house is white brick and it was pressure washed. The brick was washed so hard that the white coating on the brick was washed away in some areas. Now some bricks are the yellowish color with no white color. How can I get the white color back?

    1. Depends I have cleaned brick for 20 years, most white brick is super soft and has to be washed with very low pressure to protect the integrity of the brick, very easy for someone to blow the face off if they dont know anything. Stains depends on what they used ? Certain acids can stain white brick , they do make a product called 800 stain remover that works against alot of stains

  5. The truth is you should never pressure wash your house, but everyone does it. Learn why you shouldn t right here!

  6. You make some valid points but I dont completely agree. A correctly done pressure cleaning job can extend the life of a home.

  7. Hello. Help! How long after pressure washing should you paint your house? We pressure wash our house and on the sun facing side now it’s uneven looking. I think it needs to be repainted on that side. Unless you have another suggestion?

  8. Hello,

    Could you please help me with some info.
    I am interested in start up a small business washing fasades and stone in my town. I would like to ask you which power water pressure is required, is it ok around 200 bars? or 250 is needed? Also what is better for work electric one as Karcher Profesional HD 10/23 4 , or benzin models? What is the best option for the start? Thank you in advance!

  9. I am glad that you pointed out that it is not a great idea to use a pressure washer to clean brick sections of your home. That is good for me to know because a section of my home is brick and I have been wanting to clean the siding part of my home recently. I will have to make sure that the pressurized water doesn’t hit the brick. //www.ablasttothepast.com/residential

  10. I think the title of your article is your perception and misleading. I could point out a dozen issues with your statement. There are so many variables with power washing as you misapropriately listed above.

    I will offer you a challenge instead of insulting a profession try to bring a positive article.

  11. Soft Wash. “pressure washing”. Doesn’t matter what the situation is, algae, mold, mildew, paint preparation. Use the correct chemicals for the job. Add rubbing alcohol to your mixes to evaporate anything you think would be left behind. I have mixes for everything including snow removal, it also helps in prevention of snow to stick to any surface. 1 quart water, 3 drops of dish soap, and 1 ounce of rubbing alcohol. Simply stating use the correct mix for what ever job you need accomplished. I absolutely agree with the siding cleaning. There are correct ways to pressure wash siding at 4,000 PSI, but there are correct ways of cleaning siding at 40 PSI. Depends on the amount of money you have and obviously time. If you are pressure washing at 4,000 PSI you must have absolute attention at all times, follow the lay overs of the siding. Use your mix from bottom to top so it does not leaves drip stains. And fully rinse. As for the 40 PSI machines, I normally use an algaecide or concentrated bleach. Some key things you want to do prior to using this is severely water down and plants and grass in surrounding areas, this will allow the bleach/algaecide to not stick to the plants or harm them. Ensure you wash in a downward angle for high and low pressure washing. And finally allow the bleach/algaecide to do its job for about 10 minutes before rinsing it off. They are really not hard concepts, all achieve roughly the same cleanliness, I’m going to be completely honest even soft washing with hot water will not remove everything. You need a heavier PSI to get all of the mold/mildew/algae off. And if you’re not getting everything off I honestly see no good in washing at all as it will grow right back. Just some basics to follow so you don’t have to hire a professional. For my business I personally soft wash everything first, however when everything doesn’t come off the roof, or sides no matter what type of siding you have, it still needs to be removed. Hand scrubbing is very good where you can reach it, but doing so on a heavily pitched roof is absolutely unsafe and absurd. Grab the extension pole and 5 minutes later everything is clean.

  12. Help! A company just pressure washed my house and i think they painted too soon (about a day later). Two days after the job, my home now smells like mildew/mold! What should I do? Is this dangerous for my health?

    1. Yes that is too soon. Try running some dehumidifiers in the house and setting out some packages of damp rid. The smell will go away and the moisture eventually drop but with the house now sealed up on the outside with paint it has no where to evaporate but indoors.

  13. We have recently purchased a beautiful property with a cedar cider sided cottage. The siding is in excellent structural shape (about 6 years old) but has never been stained or otherwise treated. It’s darker than we prefer and I thinking of low-pressure washing it, then using a transparent stain. Any thoughts?

  14. Ok got it. Thanks for letting us know. Great! I think 1250-1500 psi would be best for cleaning wall. If you suggest the best one that will be great!

  15. We have an old house with asbestos siding that is in good condition. We are getting ready to have the trim work around windows painted. The house needs to be cleaned outside, though. I am reluctant to have someone power wash it because I don’t want the paint flaking off the siding. My biggest concern is under the eaves where it really needs to be cleaned. There is mesh wire that opens into the attic to keep the attic cool and I don’t want water getting into the attic. My question is: 1) should I skip the power washing and just use hose and 2) how to keep the water from going into the attic because under the eaves is where I really need to get clean! Any help would be appreciated!

    1. Sandy, I would use a hose and scrub brush. And to keep the water out of the attic which a pressure washer will definitely do. Cover up those openings with plastic during washing.

      1. Thank you for the information, Scott. I had that dreaded feeling the more I thought about it that power washing was not the way to go….I don’t think it will hard at all to wash with the hose and scrub brush. I have a helper so I think between the two of us, we’ll be able to do a good job….then on to the cleaning windows and painting! This old house is going to look really good………and I’ll be following your blog for ideas!

  16. What about a mobile home that has green stuff on it, being on the shady side of the house? Should it be low or medium pressure? Also if I do it with a hose what cleaning products would be recommended?

  17. Please help…my husband and I are rehabbing an old completely cinder block home. He wants to pressure wash the inside walls before we frame for sheetrock. I’m nervous that it may cause more damage than good. Is it safe to use a homeowner grade washer?

  18. Thank you so much for this information. What you said makes tons of sense. I will use the hose with extension pole brush to clean the siding. You save me from a future headache!

  19. Looking for a way to clean a second-story stucco wall. Have tried an ineffective hose-attached washing solution and pressure washing. Problem is access. Would need to walk on a 14 year old roof to get close enough to the wall. Any suggestions?

    1. On stucco, if the brush doesnt work you could use a telescoping wand or an extension pole for your wand and a quick connecting pivoting coupler. Dont spray any cracks or chips unless you patch them first and then you have to wait a week before you pressure wash. I wouldnt get the tip any closer than 2 Ft. unless you are using low pressure. Oh and another thing to remember when washing stucco make sure you alays pre wet the surface before washing so the dirt rolls off easier dry stucco like to grab the dirty water rolling off.
      Good luck

  20. Very good advice here, allot of people dont know how to pressure wash. I used to pressure wash professionally, and we would not pressure wash any wood siding unless they were going to paint it. Then we would use really low pressure and deck brushes with very long extenda poles, and the man on the wand would only shoot the house at a (low pressure) downward angle. If we were on a vinyl job we would mainly use the deck brushes and medium pressure shooting the water downwards and angle towards the overlap. If we couldnt use a jlg lift we would use ladders and ladders with scafolding planks. If we couldnt do it safely then we would have to turn the job down.
    I have been living in my vinly sided house for over 20 years and I have probably pressure wahed the entire house like 8 times. I just last year replaced my bedroom window with a sliding double glass door and guess what everything under my siding was completely dry and mold free. You just have to know what your doing.
    You never want to shoot vinyl siding from below because they have drain holes all over and you will shoot water right up in there. You never want to shoot vinyl towards the underlap or you will be shooting water right under the siding. On wood siding you never want to shoot it straight on because all the joints or cowboyed together and you never shoot it from the bottom either or it will go straight up under the wood siding.
    We turned down quite a few wood siding jobs because some home owner/diy’er or painters that didnt know what they doing chaulked all the over laps, which causes big problems because the water has no where to drain from rain and the wood will start to deteriorate and mold behind the siding.
    Anyway good luck to all and all there power washing needs

  21. What about pressure washing the exterior of a house that has areas of mold, but underneath, the paint job, we’ve been told, is still good–is power-washing okay, and is there a way to do it without damaging the paint? Power washing was done two years ago, but the mold is back, and a 5-year old paint job (at that time) had some areas where the paint was stripped exposing the wood.

  22. Help! What can you do if a painter DID powerwash your wood siding house, and blasted off tons of paint chips that did show to have lead?

    1. I’d like to know the response to this question as well! I live in Pennsylvania, I am a widow and on my own, I put in a modular home three years ago and this summer I noticed a slight film of black on the vinyl. Help! This is my life-end home and needs to last for me for years to come!

  23. What is your opinion on pressure washing a house that has paint in some areas? Without having the paint chip off as well as the psi power?

  24. Had my home pressure washed last week and now the basement is randomly taking in water. Plumbing company came out and said there is no leak. Any suggestions or advice?

  25. My exterminator just came to my house for a springtail infestation (tiny bugs that jump and like moisture). I live in Michigan and my roof/shingles are covered with moss and algae. It is growing up the side of my brick home above parts of the roof. She suggested getting the entire exterior of my house and roof power washed to get rid of moss, mold, algae etc. What are your thoughts on this? If you don’t think a low pressure wash is a good idea, do you have any suggestions?

  26. As a pro pressure washer, I find your article refreshing. Power today can equal pain (in your pocket) tomorrow.

  27. We live by an airport and have black grime on white plastic window frames. I believe the black grime is jet fuel among dirt and other things. If I wanted to pressure wash these window frames, what psi would you recommend?

  28. I’m getting ready to hand wash and hand paint my two story wood siding house. I may spray the primer on but everything else will be done by hand. I am getting a lot of pressure to use a pressure washer but I’m not budging. It’s an especially bad idea here in Alaska. I’m not wasting the premium paint I bought by bad prep work.

  29. Scott,
    I now need to clean the bricks on my Mom’s house — the lower ones on the sides of her house that have no gutters. The house is brick & mortar and was built in 1957. There are some new, small cracks in mortar from all the earthquakes Okla has experienced the past few years. Again, power washing has been suggested, but after the bad experience on my house (see my response to Mano), I am resisting my siblings’ insistence. Even if I have to do it alone, I’m going to use only a garden hose rather than a pressure washer.
    MY QUESTION: What product(s) should I use? What soap or cleanser? Do I scrub or just leave on awhile and rinse off with a good jet of water? Specifics please — name brands, etc. THANKS!

  30. Hi I’m selling my house and it has wood siding which totally needs cleaning. Don’t want to re-paint, just want it to look presentable and clean for when the buyers come to preview. What do you suggest?

  31. I really would like to know of one example of pressure washing causing mold damage. The little bit of water that will make it thru the cracks will surely evaporate over time. Mold needs a constant supply of water over time to start working its way. Plus, there is nothing air tight when you paint over a wall since what’s behind the paint is stucco mix crete, and chicken wire. I would
    have to see it to believe it.

    1. I see people use pressure washing as their prep for paint. So when you blast water into the walls then seal up the exterior with caulk and paint the next day that’s a recipe for disaster.

      We added vinyl siding to cover the old wood siding on our home. We added good, thick panels of insulation under the siding. 3 years later, the north and east side of our house was covered in spots of mold or mildew — it was awful and got worse.
      ——-Our house is 1943 lath & plaster. The siding is good quality and has weep holes. We added extra attic vents to the soffit and added another whirly-gig vent to the roof. There should be no problems with mold — but after pressure washing the siding – the mold move inside! — We live in Okla where the humidity is NOT as bad as it is in Houston or New Orleans! And we have lots and lots of wind to dry things out. We even had a drought —- but the spots got worse.
      Four years after adding the siding, we were talked into having the north & east OUTSIDE vinyl siding pressured washed to remove the mold/mildew. Within 5 months of the pressure wash — dark spots appeared on the INSIDE north wall of the house and grew and caused the interior wall paint to blister and fall off. Of course, the dark spots were mold or mildew or both. I didn’t bother to have it tested. I just used diluted bleach several times to be sure it was gone and then put 1,000 coats of sealer/primer that had a mold deterrent in it on the entire interior north wall before repainting.
      ——-We have lived in this house for 25 years and the ONLY thing that had changed was having it pressure washed. This INTERIOR mold problem did not appear during the 4 years after having the siding added — it appeared within 5 MONTHS after pressure washing the outside! ———- If I’d known that the siding was going to have to be HAND WASHED every 3 years or so, I would not have added siding. I would have just repainted — which has to be re-done only every 5 to 8 or more years depending on the quality of the paint.
      Also, the guy who did the pressure washing is a professional and, before painting our detached garage to which we had NOT added siding–he pressure washed it to remove peeling paint – instead of hand scraping & sanding. He did what Scott mentioned — he got too close with too much pressure and cause some of the wood to fur badly.
      A year later, when I was repainting to fix his crappy work, I had to drag out the sander, then prime the now bare spots and then paint – 2 top coats — as it should have been done to begin with. The ‘professional’ used Behr paint & primer in one — it sucks. I’d like to used the pressure washer on the ‘professional’ who caused so many additional problems!

  32. Im looking into staring at power washing buisness im new to the field and would like some tips, what type of pressure washer should I get? Gas or electric? How much p.s.i , what are things I should be aware of when starting good a pressure washing buisness such as is their any laws on the water use? Pls help

  33. I have a Spanish style plastered house which really needs pressure cleaning before painting, but we have severe water restrictions prohibiting the use of municipal water. There are many layers of paint needing removal, as the surface is chalky from paint failure. Are there any suggestions on how to clean the exterior walls?

    1. We usually clean with a wet scrub on a firm bristle brush then, scrape and sand any failing paint. Even with a water restriction you still have to wash the dirt and debris from the building before painting or the paint will not adhere.

  34. While pressure washing is a great tool to clean many surfaces; you are correct about houses. You need to adjust as a homeowner on how you want to go about cleaning the surfaces of the house. A big thing that I have witnessed some homeowners doing is pressure washing their house and have some made the mistake of washing the roof at the expense of the destruction of the shingles on the roofs. I love your tips on different pressure levels for specific surrounding areas of the house and I would have to agree of this garden hose being the primary tool for the cleaning of the walls of the residents house. Great and educational article.

  35. I moved into a red brick Victorian home built circa 1880. The cream coloured accent bricks on the house, above windows and doors and stone window sills have been painted over with white paint. Can I pressure wash the accent bricks to remove the white paint or should I consider a gentler method like soda blasting?

  36. Great article, really appreciate the post. I just bought a 90 year old home and am about to power wash. Quick question for you: our covered side porch has cobwebs and dirt. We have old columns with nice woodwork at the top that attracted lots of the grime. Should we be okay to use a power washer on a lower spray in the area, including spraying at an upward angle? The bottom side of the roof is also all wood and filthy. Want to house the whole thing down. Any thoughts? Thanks for your time , Scott!

    1. Greg, you can certainly use a pressure washer at a distance to resolve those issues. Try keeping the pressure at no more than 1500 psi and keep the tip at least 3-4 feet from the surface. That should clean off the dirt and cobwebs but not force water into places it doesn’t belong.

    2. You need a low pressure soft wash using bleach it will eat all the cobwebs and black mold. Just using water won’t work.

  37. As a pro pressure washer, I find your article refreshing. Power today can equal pain (in your pocket) tomorrow. No short cuts folks. I see lots of people who don’t get this. Treat your home with respect and a little TLC and it will treat you back well.

  38. Just added brick pavers, new step & retaining wall plus landscaping walls to my home. Caused a lot of dust. Paid 900.00 to lightly pressure wash my tile roof and house being that it is only 4 yrs old. I am now left with some white residue all almost on my whole house! Especially the front porch and the pavers are a complete mess! I paid 14k for the pavers and now they look old and gross!
    Can you tell me how to fix this? I am in shock……………….
    Thank you.

  39. The sad thing is, most people get caught up in thinking that more PSI=clean. Your cleaning agent will dislodge the dirt. As for staining, there are options for that, and high pressure isn’t one of them. With the right cleaning agents, you can apply the soap, let it sit, then rinse with a water hose; letting the soap do its job.

    1. High PSI destroys what most are trying to clean. The correct cleaners and low psi or soft washing with a little elbow grease is the answer. TLC and work always works better. I worked for a company as a regional field manager and I have seen first hand what psi and lack of experience will do and it can cost thousands to fix. I no longer work for that company because they considered themselves professionals and were making hundreds of thousands of $ destroying properties and always had fine print contracts to weasel out of responsibilities. I now have my own company and we never PSI wash homes , we soft wash and use soft brushes with eco friendly cleaners. Investigate, read and then use elbow grease , you will enjoy the outcome !

    1. If its dirty pressure wash it! Soft wash. Bleach does all the work. No high pressure and it will be all good!

Leave a comment!

Keep the conversation going! Your email address will not be published.