Thank you for visiting Rosie On The House, the online home to Arizona's longest running weekend radio broadcast!
[aws_search_form]

What is Efflorescence?

Efflorescence is not a rock band. That’s Evanescence.

Efflorescence is the white, chalky substance that appears on concrete, pavers, brick, and stucco. It is residue that is left behind when hard, salty water evaporates. It can be caused by groundwater, which is notoriously hard in Arizona or caused by rainwater.

Common causes of efflorescence are irrigation sprinklers overreaching and watering the exterior of the house and patio constantly. It can also develop following a heavy rainstorm.

While it is typically a cosmetic issue, according to the International Association of Certified Home Inspectors, it can also be a sign of moisture intrusion that may represent a structural issue down the line. Once it appears, there are steps you can take to rid the surface of what could be deemed an eyesore.

Removal options will differ depending on the surface it has established itself, with concrete being a bit simpler to treat versus stucco. IMPORTANT: Before removing, confirm that the substance is efflorescence and not mold. Mold will typically only develop on organic substances, but it can feed off of dirt within cracks found on brick or concrete. A few simple tests can be done to determine what exactly it is. If you pinch the substance between your fingers, efflorescence will break down into a powdery substance, while mold will not. You can also take a glass of water and drop some of the substance into it. Mold will not dissolve. Efflorescence will. If you have mold, call a professional mold remediation specialist.

Removal from Concrete, Pavers & Brick

There are different solutions depending on how hard you want to work. Sometimes the stains can be removed by simply washing them away with water. However, if they are stubborn, mix a solution of one part vinegar to five parts water before scrubbing it off with a stiff brush. You may also use a power washer to remove stubborn stains that water alone did not wash away. If you go this route, be sure to not exceed 1,000 psi.

Removal from Stucco

Stucco can be a bit more involved. You need to be mindful about not damaging the stucco in the process. Similar to concrete, a power washer can be used. Again, do not exceed 1,000 psi for the water pressure. We recommend using a 40-degree fan nozzle and holding it roughly 15-18″ from the surface. Be careful of flying chunks of material. Stop immediately if you see them. Lower the pressure and increase the distance from the wall before continuing. If stains remain, add diluted trisodium phosphate (TSP) to the washer’s secondary pickup tube, which can be found at any home store.

Regardless of the surface, when removing efflorescence, wear protective eyewear. Small particles or even chunks of the surface can fly around and land in your eyes.

Prevention

Unfortunately, there is no way to completely prevent efflorescence from occurring, but you can limit its severity and frequency. The easiest way to prevent build-up is to eliminate sources of water from depositing on the surfaces on which it forms. This can involve changing the location of the sprinklers throughout your yard to avoid excess water depositing on the concrete or walls.

For stucco, use elastomeric caulking on any cracks you find. Seal gaps around windows, doors, plumbing fixtures, and anything else that would allow water to get underneath the stucco. Be careful to not caulk weep screed found at the bottom of the stucco.

IMPORTANT: Do not cover the entire wall with this type of paint or caulking as they will trap moisture and create more problems. Consider priming the walls with an alkali-resistant sealer that will assist in neutralizing the efflorescence. Following the application of the primer, using a sprayer, apply a good amount of 100% acrylic paint, aggressively working the paint into the surface of the wall with a roller. A sprayer alone won’t ensure every nook and cranny is covered.

###

PODCAST

Our Weekly To Do explains that white, crusty stuff on concrete and stucco called efflorescence. Plus homeowner questions on pool excavation, pool shotcrete, rotten wood feature, window leak, doors not closing flush and the best way to maintain your home with the Rosie On The House Home Maintenance App powered by HomeZada.

Podcast Archive With Expanded Content and Resources

 

PHOTO CREDIT

  • Shutterstock

 

CONTENT RESOURCES

Find Rosie-Certified Contractors in your area today

All contractors are Rosie-Certified for the state of Arizona.

Others Articles from Concrete
Gardening & Urban Farming
Gates & Fencing
Mold Remediation | Water & Fire Damage
Painting & Wall Covering
Restoration
Stucco

Explore Other Categories

DYI Categories Filter
Display More

Leave a Reply

Your email address will not be published. Required fields are marked *

Event Promotion Request

  • This field is for validation purposes and should be left unchanged.