This aint your normal paint job. Painting concrete is a whole other animal compared to painting drywall. Drywall can be painted in a day or two, you will need at least a week to properly paint cement. The trick lies in the cement itself, it breathes, absorbs moisture, and sucks up paint. We think concrete looks fine itself, but if you are set on painting your concrete, here are the steps.
1. Clean the Concrete
Now this involves more than just spraying it down with some water. Concrete is a porous substance by nature and tends to trap dirt, grease and grime. Dirt and grease can be removed by using trisodium phosphate. Remove any vines or moss with a power washer. After you have done this you may notice a white powder on the concrete called efflorescence, which occurs on moist cement. This can be removed with a masonry cleaner.
2. Strip any old paint
If you are painting basement walls, and there is an old layer paint, remove with a wire brush or a paint scraper. If you are working with outdoor concrete this can be accomplished with a pressure washer.
3. Seal Interior Concrete
Still want to keep going? If you’ve made it this far there are only a few more steps, but at this point you have clean concrete so we won’t blame you if you stop here. As previously stated, concrete is porous, and can absorb moisture. If you are painting interior concrete it is vital to seal the concrete. This will prevent moisture from seeping in underneath the paint and causing mold. Use a masonry sealer and follow the manufacturer’s directions on how many layers to apply and when. As well as keeping out moisture, this will also help seal any cracks that may be present, a win-win.
4. Prime the concrete
Almost there. Like painting drywall, concrete needs to be primed, and the type of primer you use will depend if you are painting interior or exterior concrete. Concrete primer, or block primer serves two purposes, it will fill any gaps and cracks, and present an even surface to paint on. After the primer is applied you will want to wait a minimum of eight hours before you paint, but no more than 30 days!
5. Paint the concrete
You’ve made it this far, so don’t mess up the type of paint. Masonry paint is designed to expand and contract with the concrete, whereas exterior paint will crack. You will also need a masonry brush as masonry paint is much thicker than normal house paint. If you have a paint sprayer make sure you consult with someone at the paint store so you don’t clog it with the thick paint.
You made it! Now you have some beautifully painted concrete!