Tim’s house is only a year old, but he’s noticed some stubborn stains on his white stucco walls caused by rainwater channeling down from the flat roof. He’s tried a bleach and dish soap solution without success and wants advice on how to remove the stains.
Hi, my house is 1 year old, but I'm getting a stain in a couple of areas from where rain is channeling down from the flat roof capping and along the stucco. I've tried the bleach/dish soap/water mixture, but it doesn't seem to remove it. Any suggestions on how you'd try to get that stubborn deep stain out?



Answer:
Hi Tim! Thank you for your question and the photos. Stains on white stucco, especially cement-based finishes, can be notoriously stubborn because these finishes tend to absorb almost everything. Here are a few things to consider and additional methods to try:
Reassess the Bleach/Dish Soap/Water Mixture
You mentioned trying this mixture, but did you allow it to sit on the stain for about 10–15 minutes before scrubbing or rinsing it off? Sometimes letting the solution soak for longer can help lift deeper stains. You can also try a second application for more persistent spots.
Try Pressure Washing
Pressure washing can be a great option for tougher stains. If you have access to a hot water pressure washer, it would be even better, as the heat can help loosen the dirt and grime embedded in the stucco. Be sure you use a medium pressure setting or tip to avoid damaging the finish.
- Tip: Start with a lower pressure or wider tip spray pattern and test it on a small, inconspicuous area first. Avoid concentrating the spray on one spot for too long.
Specialized Cleaners
There are commercial stucco cleaners specifically designed for cement-based finishes. These cleaners often contain stronger detergents or mild acids to break down stains without damaging the surface. Check your local hardware store or online for options, or look for cleaners labeled safe for stucco.
Understanding White Stucco Challenges
White stucco, while beautiful, is one of the most unforgiving colors for stains. Cement-based stucco, in particular, is porous and absorbs water, dirt, and other debris over time. Stains from rainwater channeled along the surface can be especially challenging to address.
Once you've cleaned the stains, you may want to consider sealing the stucco with a clear water-repellent sealant to prevent future staining.
Let me know if you have tried any of these methods or if you need recommendations for specific cleaning products. Good luck!