How To Paint Cinder Block Walls In The Basement
If you are talking about painting BARE cinder block, and are looking for water resistance, we exclusively use latex-based DRYLOK. It is an extremely heavy, gritty product compared to a regular paint. You will need to prep the surface by cleaning it as well as possible with a metal wire brush, and make sure that the wall is perfectly dry before applying the sealer. We suggest a very thick, (1 inch or more,) roller cover, so that you may press the material into the cracks on the cinder block, filling it completely. Back-brushing while the paint is still wet will help work the coating into the block, and water resistance only happens if all the little areas are completely filled in. A 4″ brush works best for this. DRYLOK makes a brush specifically for this application (it is lightweight and helps reduce hand fatigue, which WILL happen during this process) and is worth investing in if you are lucky enough to find a store that carries it. Please expect a great deal of paint spritz with this product / roller combination, and use butcher block paper to completely cover the surrounding floor. This product dries rock hard, so we never suggest using a drop cloth or any other re-usable floor covering.
One downside of this product is that is it not tintable and only comes in a flat sheen. If you are looking to add some color and/or sheen for a smoother appearance, we suggest adding a high quality exterior paint as a top coat. Exterior paints are less likely to crack or flake out over time due to their high build (thickness), durability, and mildew resistant properties. Valspar Duramax is our go to product for this application, and Sherwin Williams Duration or Benjamin Moore Aura are great alternatives.
Please be aware that when using either of these products that an organic vapor respirator should be used, and any downstairs / indoor areas should be vented as much as possible. These are strong, industrial level paint products, and produce strong fumes. (Though both are still latex based, so are at least easy to clean up!!) And lastly you will only get about 80 square ft of coverage per can with DRYLOK compared to 350-400 square ft of coverage from a standard topcoat, so make sure to measure your walls before making your purchase and plan accordingly.
DRYLOK can be found at the larger box stores like Lowe’s and Home Depot, and also most other hardware and paint stores, around $25/gallon.
Please like and follow us at https://www.facebook.com/justaddpaint