It's a contentious issue. Half of the designers, paint contractors, and homeowners vehemently say that brick should be left in its natural state–unpainted. The other half says that not only can poor quality brick be painted over, but good brick will look better when painted.
Painted Brick and Its Permanance
In the end, it has less to do with the look of it than with permanence of the project. It is difficult to remove paint from brick: sandblasting; laborious manual stripping; or pressure-washing.
Consider that painted interior brick is even more permanent because it rules out the possibility of pressure washing or sand-blasting the paint, should you decide to reverse the project.
Undertake this project with much consideration and care. View it as irreversible.
One tip right off the bat: this is one project where it is more about materials than technique.
How To Do It
- Efflorescence is that white, chalky stuff that appears on brick. If you have any efflorescence, then you need to remove by hand wire brushing without water. If this is exterior brick, try lightly power-washing. Careful: washing with too much power will etch the brick.
- Does your brick have large cracks? Brush them out with the wire brush so that any loose material is removed. Seal with pure acrylic or silicone/acrylic caulk designed for exterior use.
- Often, the mortar is crumbling or even missing. This means that you need to repoint your mortar. Deeply inset or missing mortar means that your painting job will be that much harder. So, while repointing may seem unnecessary at this point, it will save you work later in this process. See also this video about tuck-pointing brick mortar.
- Scrub down bricks with mild detergent and scrub brush. Or use a power washer, if you haven't done this in an earlier step. If you have mold and/or mildew, remove by adding 1 part of ordinary household bleach to 3 parts water. Moss is relatively simple to kill with a spray-on fluid such as Bayer 2-in-1 Moss and Algae Killer.
- Wait for brick to dry. We mean dry! Let bricks dry thoroughly before attempting to paint. Because brick is very porous, it may feel dry to the touch but is wet inside. You may want to let a day or two of dry weather pass before attempting to paint.
- Roll, brush, or spray on coat of conditioner paint such as Sherwin-Williams Loxon.
- Let the conditioner dry for 3 hours. Be careful not to let too much time pass or the surface will get dirty and need to be recleaned.
- Paint with coat of 100% acrylic elastomeric wall coating similar to Valspar Duramax.
- Let dry thoroughly.
- Paint second coat of elastomeric wall coating.