Asked on Oct 19, 2016

How to clean exterior stone

P.  Collier
by P. Collier
I live in Tulsa and my house has a stone exterior that had become darken in some areas. Does anyone know how to clean this stone? Sorry, I don't know the name of the stone I moved from illinois and I never saw stone like this. Thanks for your help!!
q how to clean exterior stone, cleaning tips, concrete masonry, house cleaning
  24 answers
  • Pam Lewandowski Pam Lewandowski on Oct 19, 2016
    It's beautiful. I'd use a pressure washer. I would think they could be rented at Home Depot or Lowe's. We're here in Tx and we used it to wash bricks and concrete. Best of luck!!! :)

  • William William on Oct 19, 2016
    Don't use too much pressure so you don't affect the mortar. You can also apply a sealer after cleaning.

  • Norma Norma on Oct 19, 2016
    I agree -- rent a power washer (some Home Depots rent them) but don't use the hardest tip. Practice in a unnoticeable corner. You can get cleaner to use but truthfully I've never noticed a difference when its used vs. water. I have 2 garden walls and a stone patio that my son built years and years ago and every year he power washes them and they look like new. It'll be a little tedious tho because to do it right, you have to do each stone individually and that'll also protect the mortar. Good luck!

  • Md24576932 Md24576932 on Oct 20, 2016
    I put bleach in a spray bottle and sprayed the blick.Then I scrubbed the brick with a stiff brush.Rinse off with water .That's all u got to do

  • Marsha McMichael Stutts Marsha McMichael Stutts on Oct 20, 2016
    When we had our stone patio built, I asked the stone mason what to clean the stone with. His answer, "White vinegar and water, mixed half and half." You can use large sponge (Lowes has them in the paint section). You can also use a stiff bristled brush with the vinegar/water mixture. Be careful if you decide to use a pressure washer. It will remove the mortar from between the stones. Use the lowest PSI tip with the pressure washer. Good luck!

  • Jbc9527367 Jbc9527367 on Oct 20, 2016
    On my fireplace brick, I used oven cleaner. I covered the area that I did not want to spray (newspaper), sprayed and let it set for a while. Then using a brush, cleaned it, then wiped with a cloth.

  • FRED RIGGS FRED RIGGS on Oct 20, 2016
    On the outside of the house. I use my pressure washer. Never use the pin point setting, fan spray only. You can take a garden sprayer, put soap, a half cup of bleach, but be careful with it. Spray it generously, scrub brush after 15 minutes or so to loosen heavy stains, then pressure wash. Stay away from windows, you can break them. Stand about 4 feet away. Do one section at a time and take your time. Stubborn stains may take more scrubbing. When you are done and satisfied, rinse with your hose liberally and check results when dry. If some mortar comes out, get some mortar mix and regrout. It was not in good shape anyway. I had to do that in 20 or so spaces. Dampen the joint first then grout and don't do it on a hot day when the water would evaporate quickly. It needs to cure sort of like concrete. Patience is the best cleaner. Take your time. You can even use TSP from the hardware store to scrub with. USE GLOVES, no matter what you scrub with. Wear protective eyeware and very old clothes.

    • Merv Merv on Aug 28, 2018

      Years ago I used TSP on my smoke stained brick fireplace and it dissolved the mortar. As soon as I noticed I rinsed copiously with water, but the chemical reaction left the mortar soft even much later. I knew others who used and recommended TSP, one a chemically say lab tech. I don't know what the difference was. My fireplace was built in 1954 as was hers, both in the same town. Years later the mortar was still soft and crumbly on the surface and I didn't try going deeper. A clean freak friend painted her much nicer brick fireplace white, which actually turned out ok until she had a fire in it. Soot on white is even more noticeable than on bricks.

  • Ag Castor Ag Castor on Oct 20, 2016
    This is just mildew. Spraying with half ordinary bleach and half water will take care of it and avoid power-spraying water under the stone veneer. As a bonus, ordinary bleach, sodium hypochlorite 5%, breaks down into NaCl, table salt, and H2O, water, nontoxic to your environment.

  • Moe Moe on Oct 20, 2016
    Spray wall with bleach, it takes little scrubbing.

  • Peter Kovak Peter Kovak on Oct 20, 2016
    For such a large surface it's only power washer. You can even do it with a sand blower, only that is more expensive and messy for the garden, but the result is astonishing. For the whole exterior of the house...well, forget about manually doing it, you know, with a little sponge, bleach, brush, water spray and whatever. Even with power washer it takes a couple of hours, so think twice before doing it only once! And enjoy!

  • Smu1485110 Smu1485110 on Oct 20, 2016
    I used white vinegar and a scrub brush on my interior fireplace and it removed the black soot and lightened the stone where it had darkened from age.

  • Barbara C Barbara C on Oct 20, 2016
    Soot is not mold. takes a much stronger mix to get rid of mold spores.Strong bleach is best.

    • Ljgordon Ljgordon on Mar 20, 2020

      Bleach only gets rid of the mold stain, it doesn't get rid of mold spores completely. Try Wet and Forget from a big box store.

  • Diane Ward Diane Ward on Oct 20, 2016
    as the wife of a stone mason, i suggest calling a profesional. they use muric acid and have the right equiptment and know how.

    • See 1 previous
    • Kristine Jean-Marie Kristine Jean-Marie on May 31, 2018
      A stone mason. They know anything there is to know about stone and how to care for it.

  • Jen Jen on Oct 20, 2016
    Power washer at low ought to do it!

  • Sharon Sharon on Oct 20, 2016
    It's called fieldstone and power washer will do the job. You also can add DAWN dish soap if your washer comes with that attachment.

  • Terri Farina Terri Farina on Oct 20, 2016
    In Rome they are cleaning the great arena with water and tooth brushes. They expect to be at it for 10 years. I would start with an assortment of brushes (soft to stiff) and a bucket of water with Dawn dish soap. Start with the softer brushes and work up to the stiffer brushes to find the best one. Finish with a power washer starting at the softest spray level.

  • Bernadette Staal Bernadette Staal on Oct 20, 2016
    Usually I would suggest just using a water blaster but that could blow out the compound holding the stones in place which would possibly cause issues with leaks or similar. I would get a professional into spray the rocks with a soft wash / chemical solution.

  • 1268409614 1268409614 on Oct 20, 2016
    You can buy a presser washer that does an okay job or rent an industrial pressure washer that will do a great job just be careful when using it.

  • Helen Rhodes Bodenheimer Helen Rhodes Bodenheimer on Oct 21, 2016
    simple way is to spray the rock with bleach and let it set for a few minutes then wash away with the hose

  • Diane White Diane White on Oct 23, 2016
    First, be sure it truly is rock and not a composite.

    • B. Enne B. Enne on Oct 31, 2016
      If it is rock and you don't have a huge area to do, you can use the aerosol form of the bathroom cleaner Scrubbing Bubbles. Avoiding direct sunlight, wet the area 1st (a regular hose will work), spray SB on lightly, leave on for about 5 minutes and rinse again.

  • Janet Mayer Janet Mayer on May 13, 2018
    I have sandstone on my exterior. We tried power washing. Didn't do a thing to clean it. I talked to a professional who said he didn't know how to clean it and that it was carbon (from all the car emissions after 68 years). I am at a loss. Tried Dawn and scrubbed. Nothing. If anyone knows who to call, I'd love to have it cleaned.

  • Fiddledd224 Fiddledd224 on May 13, 2018
    Power wash with Awesome Orange mixed into cleaning solution

  • Sarah Lowery Sarah Lowery on May 25, 2018
    Hi Janet, I will help you. I own a pressure washing business and can help you. Please give me a call so we can talk, if I don't answer it's because I'm working so please leave a message so I can call you back.
    Sarah L. Owner
    Power Trip Pressure Washing
    My website is

  • Stephanie Jones Stephanie Jones on May 15, 2020

    I have new Mountain Stone that has black all over it and has to be cleaned. Dawn isn’t working. The stuff my Masionery went and got din’t work either. Any suggestions?

    Thank you