Stucco, a form of siding made from a cement mixture, can be a fantastic choice for your home’s siding. It provides a seamless look that is relatively low maintenance. However, due to its porous texture having tons of small rigid edges, stucco can trap a lot of dirt and dust making it appear dirty if not cleaned regularly.
A common question people ask is, “Can you pressure wash stucco?” The answer is, yes, you can pressure wash stucco. However, stucco is prone to cracking which can allow moisture to seep into the wall. The key is to make sure you have all cracks properly addressed before pressure washing.
Pressure washing can be one of the most efficient and effective ways to clean your stucco exterior if done properly. Continue reading this article to find out how to properly pressure wash stucco without damaging it and several other effective ways to keep your stucco siding looking the best it can. Let’s get started!
Problems with Pressure Washing
There are a lot of misconceptions out there regarding pressure washing stucco and the damaging effect it might have. This is largely due to the belief that stucco is too brittle to handle the force of a pressure washer. While it is true pressure washers are capable of putting out some serious pressure (most can put out over 2,000 PSI or over 200 mph!), stucco is actually quite resilient and normally does fine under this type of pressure.
The problems arise when there are existing cracks or chips in the siding prior to pressure washing. Cracks will allow the water to seep past the siding and into the underlying wall where it will be trapped and cause wood to rot and leaves the potential for mold to grow. To avoid this pitfall of cleaning your stucco siding, all cracks need to be filled prior to cleaning.
Prepping Stucco For Cleaning
To properly prepare your stucco to pressure wash, visually inspect the entire surface area that you will be spraying and note any existing cracks or chips that would allow water to get through.
When you have identified the areas you need to fill in, use a stucco repair caulking to fill in all the gaps you can find and let the caulking dry. The caulking will start to harden within a few minutes so make sure you get it properly set in the crack. Allow the stucco to fully dry and harden over the course of the next couple days.
Here is a super helpful video about how to properly seal cracks in your stucco using stucco repair caulking. (Repairing cracks and chips in your siding should be regular practice and not just when you intend to pressure wash).
https://www.youtube.com/watch?v=H8o6ADu6T3c
Properly Pressure Washing Stucco Exterior
Once you have completely sealed all visible cracks throughout your stucco’s surface. Begin by loading a mold and mildew fighting detergent into your pressure washer and applying that to the section of wall you will be washing. Spray the detergent evenly going from bottom to top.
Give the detergent about five to ten minutes to start working its magic before you begin pressure washing that section of the wall. However, DO NOT give the detergent time to fully dry otherwise you will need to repeat the process over again.
Use a 20 degree pressure washing nozzle and set your pressure washer to spray around 1,500 PSI and test it on the wall. If it appears you will need more spraying power, start adjust the PSI up slowly until you can confidently remove all dirt from the wall. Stand approximately 2 and 1/2 feet away from the wall and spray from a 45 degree angle. Start rinsing away the detergent from top to bottom until the wall section has been completely cleaned.
Then, move to the next section of your wall and repeat the process over again until you have made your way around the entire surface area you intended to clean.
NOTE: Avoid spraying windows as the pressure washer is very capable of damaging them.
For heavily stained areas or areas where rust is present, it is best to scrub by hand with a moderately stiff bristled brush and a soap and water mixture (Dish soap works great!) to loosen up the dirt and grime before using the pressure washer.
Be careful when scrubbing the stucco to not apply too much pressure. Vigorous brushing can start to wear away the texturing and cause the stucco to chip. Work in small circles, applying moderate pressure throughout. It’s a very similar motion to brushing your teeth.
There is also a scrub brush handle attachment for your pressure washer that works wonderfully but is not completely necessary.
If you are dealing with an extremely bad stain that is still not coming off with detergent or soap, experts recommend creating a mixture of Trisodium Phosphate.
This chemical is a common cleaning agent and can be found in most hardware stores. Simply mix a combination of TSP in a bucket with water (Use a ratio of 15:1, water to TSP) and apply the solution to the problem area with a scrub brush. Allow the solution to set on the area for an hour or two and then proceed with the cleaning techniques described in this article.
Before using Trisodium Phosphate, make sure you ventilate the area well and wear gloves when applying to avoid the solution making contact with your skin.
If You Don’t Have a Pressure Washer
If you haven’t quite made the plunge and bought a pressure washer yet, that’s okay. Pretty much all of this article still applies. You can use a garden hose with a spray nozzle that allows you to adjust the stream similar to the nozzle of a pressure washer.
You might have to put in a little more effort scrubbing problem areas beforehand but if you don’t have a ton of surface area to clean, you can get away with this method just fine.
Obviously, if you are cleaning interior stucco, you won’t be using a pressure washer anyway! (or a garden hose for that matter). If you are cleaning interior stucco, this article still applies you will just need to use a different method to rinse the cleaned area.
A clean, soft bristle brush works great. Just continue to rinse the brush in clean water and lightly scrub the area where your cleaning agent was applied until the solution is no longer visible. Then, simply let it dry.
Stucco Maintenance
As previously mentioned, one reason why stucco has been such a popular choice of wall covering alternative for so long is it can be extremely low maintenance. It’s durable and provides a seamless look that responds well to most climates.
The key to keeping your stucco in peak condition is maintenance. Repeat the steps discussed in this article as often as necessary and make sure to visually inspect your stucco regularly.