Google Answers Logo
View Question
Q: Cleaning Stocco Coated Concrete ( Answered 5 out of 5 stars,   1 Comment )
Subject: Cleaning Stocco Coated Concrete
Category: Miscellaneous
Asked by: tick-ga
List Price: $5.00
Posted: 07 Jul 2003 11:22 PDT
Expires: 06 Aug 2003 11:22 PDT
Question ID: 226124
I need a way to clean some of the "Stucco" coating that is applied to
parts of my home foundation. Will Muriatic Acid work?
Subject: Re: Cleaning Stocco Coated Concrete
Answered By: pinkfreud-ga on 07 Jul 2003 12:41 PDT
Rated:5 out of 5 stars
I've found several online sources that provide information about
cleaning stucco. Although one of them mentions muriatic acid for
stucco, it appears that trisodium phosphate (TSP) is the preferred

"Cleaning Stucco 
To give a stucco wall a fresh, new look, clean it with a garden hose
and sprayer filled with a very dilute solution of trisodium phosphate
(TSP). Be sure to thoroughly rinse off the mixture."

House and Home: Stucco Siding

" 1 gallon warm water 
  1 quart household bleach
  1 cup trisodium phosphate (TSP) 

Apply the solution to the entire area and lightly agitate with a soft
bristle brush. Then rinse thoroughly with clean water."

ABC Good Morning America: Stuck on Stucco

Similar advice is found here:

"Stucco Cleaning Solution

Stucco finishes that have become soiled may be cleaned by the
following solution:

1 gallon warm water 
1 quart household bleach 
1 cup trisodium phosphate (TSP), available at Home Depot paint dept. 
Apply the solution to the entire area and lightly agitate with a soft
bristle brush. Rinse thoroughly with clean water.

For heavily soiled areas, commercially available products such as
'Wash Down' and 'Finish Up' are available locally from Demand
Products, 770-772-7448.

Whenever cleaning a synthetic stucco surface, it is imperative that
gentle brushing and agitation be used versus forcefulness. All
applications and rinsing should be as gentle as possible, as excessive
pressure may do more harm than good."

The chemicals from Demand Products mentioned in the article above may
be purchased online:

Demand Products

Here's a good article about cleaning stucco (I would be cautious with
the advice about using a power washer, though, since the stucco on
your foundation is likely to be a veneer that could be damaged if
water is driven underneath):

Do It Yourself Network: Cleaning Siding, Stucco and Brick,2058,7649,00.html

Here's some detailed advice:

"Cleaning Stains 

Occasionally, mud stains (typically occurring at the foundation level)
and stains resulting from extractive bleeding of wood trim may require
more than a water cleansing. If these stains are treated at first
notice, they can, in most cases, be removed successfully. To remove
these stains, a solution of Trisodium Phosphate (TSP) and water, or a
very light solution of Muratic Acid and water may be utilized. Both
these items are available at hardware stores or building supply
outlets. Some laundry detergents, such as Tide, contain TSP. With both
of these solutions, a small inconspicuous area should be cleaned first
to test the results.

When using TSP: 

Pre-wet the area and any area below it. 
Make a paste-like solution with water and apply to the area with a
stiff bristle brush.
Allow to remain for a short time. 
Rinse thoroughly to remove any residue. 

When using Muratic Acid: 

Pre-wet the area and any area below it first. 
Mix in a plastic or rubber pail a very light solution. Add 1 part
Muratic Acid to 18 parts water. Do not mix any stronger, as this may
etch the stucco surface. Always add the acid to the water to avoid
splashing or reaction when mixing.
Apply with a stiff bristle brush to the area. 
Rinse immediately very thoroughly to remove any residue. 
NOTE: Muratic Acid is highly corrosive and caustic. Protective
goggles, gloves and clothing should be worn when using this material.
Extra care should be taken to insure this solution does not contact
any areas or materials other than the stained stucco, as unwanted
damage could result. (Consult Material Safety Data Sheet)
If either of these 2 methods fail to clean the area, you should call a

Reitter Stucco

One bit of advice, based upon experience: as you work, try to keep the
cleaning solutions from saturating the grass and soil around your
foundation. Once I carefully cleaned my concrete foundation, only to
find that the chemicals I'd used had created a grass-free zone
surrounding my house. Nothing green (not even crabgrass or dandelions)
would grow near my foundation for several years thereafter.

A second bit of advice: CLR Industrial Strength Cleaner works very
well at removing discoloration from cement, and the label says it's
good for stucco, too. It's available from stores like Home Depot, and
from many places online:

Do It Best

Another commercial product that might interest you is Quikrete
Concrete and Stucco Wash:

"Ready to use, no mixing required. Used for removing mildew, algae,
black mold and light soil stains from concrete, stucco, brick,
flagstone and wood surfaces."
Do It Yourself

Search terms used:

"cleaning stucco"
"how to clean stucco"
"stucco" + "muriatic acid"
"stucco" + "trisodium phosphate"
"stucco" + "tsp"

I hope this helps! If anything is unclear, or if a link does not
function, please request clarification; I'll gladly offer further
assistance before you rate my answer.

Best wishes,
tick-ga rated this answer:5 out of 5 stars and gave an additional tip of: $5.00

Subject: Re: Cleaning Stocco Coated Concrete
From: pinkfreud-ga on 09 Jul 2003 13:06 PDT
Thank you very much for the five-star rating and the generous tip!


Important Disclaimer: Answers and comments provided on Google Answers are general information, and are not intended to substitute for informed professional medical, psychiatric, psychological, tax, legal, investment, accounting, or other professional advice. Google does not endorse, and expressly disclaims liability for any product, manufacturer, distributor, service or service provider mentioned or any opinion expressed in answers or comments. Please read carefully the Google Answers Terms of Service.

If you feel that you have found inappropriate content, please let us know by emailing us at with the question ID listed above. Thank you.
Search Google Answers for
Google Answers  

Google Home - Answers FAQ - Terms of Service - Privacy Policy