How To Paint Exterior Concrete

A step by step tutorial to paint your outdoor concrete walls like foundations, stucco, and mortar.

Have you ever completed a project and afterwards thought, “Wow! Why didn’t we do this sooner?!” This is one of those!

How to Paint Exterior Concrete, Stucco, and Brick Foundations

We are rolling along in the remodel of my childhood home as we prepare to put it up for sale. The house exterior has been stained, a new budget friendly walkway put in, and we rebuilt the front and back decks. It’s really starting to come together, friends!

The exterior mortar needed a bit of a refresh and the sealer had deteriorated. I wanted to brighten it up, while also removing stains and cracks.

Although this home is log cabin style, this process is exactly the same for areas like cement or brick foundations, cinder block walls, and mortar stucco style walls.

Materials

Pressure washer (optional)
Strong Degreaser if you have greasy stains. Deck or House Exterior cleaner will do if you don’t have greasy stains.
Handheld grinder if you have uneven places or large cracks to repair. You may be able to rent one from the hardware store.
Patch filler – since this is filling walls. I recommend buying powdered mortar or cement to match to fill in cracks.
Adhesive roller and Painting pole
Paint brushes
Paint (Behr Waterproofing Paint or Exterior Masonry Paint – see below)
Large stir stick

How To Prep Concrete for Painting

For most uneven parts, a handheld plug-in grinder with a 4-inch diameter diamond bit grinder blade work well.

Prepping a Concrete Wall – Stains & Cleaning

There are several issues you may encounter while painting exterior masonry and concrete. Here are some challenges we had to navigate:

BIG cracks
Stains from spills
Previous patches that didn’t match color or texture

Step one is beginning with a clean surface area; properly clean and dry the concrete. Since we stained the entire house as well as painted the mortar, a pressure washer and exterior house cleaner or mold remover worked very well. It was amazing how much grime and mildew came off!

Filling Cracks

If I had this to do over again, the one thing I wouldn’t do is use pre-mixed tubes for patching concrete. It is cumbersome to work with. Half of them broke out of the back, creating a terrible mess. The texture is goopy and too thin for successful wall application. We tried several brands without better luck.

LESSON LEARNED: DO NOT USE PRE-MADE CONCRETE PATCH ON WALLS!

Normally, I would’ve mixed up some mortar to the consistency of thick peanut butter and filled cracks that way. If you have small cracks, you can use a grout bag like this one. It’s sort of like a piping bag you use for frosting cupcakes.

You can also use a fast setting hydraulic cement like this one to fill cracks in walls. As an added bonus, it acts like a waterproofer for leaks.

Best Concrete and Masonry Paint to Use

There are several choices when deciding on a paint for exterior concrete walls and foundation walls. I will explain the difference.

Behr Dry Plus is a waterproofing paint that helps with any moisture issues. It can resist up to 12 PSI of water pressure. This paint is perfect for a basement that is underground or any area prone to dampness. Paint isn’t a substitute to repair leakage problems, but this paint is a quality waterproofer. The one drawback? This product comes in a limited color selection.

One the other hand, Behr Masonry, Stucco and Brick paint is excellent for exterior applications where waterproofing under pressure isn’t needed. It has excellent hide, coverage, adhesion and water repellency. This is the product we chose for our exterior application and we are thrilled with our results.

The last consideration is Behr Elastomeric Masonry, Stucco and Brick Paint. This product is mostly used to even out a surface. It will fill in hairline cracks (cracks that don’t go very deep or are tiny) but it won’t perform miracles. You’ll still need to patch anything larger.