How to Paint Over Efflorescence?


Have you noticed white patches all over your walls? This is a typical painting problem that homeowners and managers experience, and if not treated properly, other issues might occur.

Let’s learn about the causes, consequences, and solutions to fix efflorescence quickly and effectively.

What’s Efflorescence?

Typically, bricks are bonded with a mortar and other binding materials that contain calcium carbonate, and when rain occurs, sometimes the water passes through the walls. Then, the water comes back to the surface and evaporates while the acid and salts dissolve. As a result, crusty white salt deposits arise in the form of steady patches or drip marks.

Efflorescence Causes 

There are three main reasons why efflorescence develops and why it is visible internally and externally from concrete:

1. Water Infiltration

If you notice damp patches on walls after heavy rains, there must be water seepage on your home. Therefore, you have to find the source and fix it.

2. Unprepared Surface 

Before painting or renovating walls, the surface needs to be clean by removing all previous salt deposits and fully cured. If you don’t follow the right procedure, issues such as efflorescence might take place.

3. Thermal Difference 

When this happens, not much can be done. If you live in high-places, keep your home ventilated by opening your windows and doors often.

Efflorescence Effects  

The white deposits (or soluble salts) can appear on concrete, brick, block, stucco, mortar, and other masonry surfaces, creating an unattractive appearance. Besides, deposits might grow and cause adhesion problems, if not properly removed before repainting.

Other effects are physical damage to the structure and property value’s reduced value.

Remove and Paint Efflorescence Surfaces

The first thing to keep in mind is not to use any liquid substance other than a clear coating or efflorescence-cleaning products.

You could remove the efflorescence and all other loose material (dirt, unbound sand, and deteriorated paint) with a wire brush or pressure washer. We recommend to use the following solution:

  • One part phosphoric acid to seven parts water. For safety, always add the acid to the water, never add the water to the acid.

Then, rinse thoroughly and allow the surface to dry completely. Moreover, make sure that the moisture source has been removed and proceed to repair and repaint the walls, with a premium-quality acrylic finish.

Top-Quality Painting Services 

If you’re interested in painting over efflorescence surfaces, contact Gilbert’s Painting. With over 27 years of experience, we’re Arizona’s best full-service, licensed, and insured painting company.

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