Start with freshly-cleaned concrete walls. Use a brush to scrub into basement wall crevices.
To keep moisture from seeping through and to inhibit mold growth, prepare sealer according to the package's directions. Spread the sealer on the wall and let it cure for about a week before applying a second coat.
Apply a layer of block-primer to prepare the walls for paint, then wait a minimum of eight hours before painting.
Apply masonry paint with a masonry brush or high-capacity paint roller. Let the paint dry completely then add two or three more coats as needed.