We’re finally back on speaking terms with the basement. After a rough run-in with mildew during our first Drylok attempt, we feel accomplished having completed the first major step toward turning a cinder block insect shelter into a clean, functional storage area.
If you remember, mildew broke through our first coat of white latex-based Drylok and left us disappointed. After a second round of bleach treatment to tame the mildew, we moved on to the oil-based Drylok that True Value staff recommended for stronger protection and durability.
The oil-based formula is potent—very smelly—so we used professional-grade respirators while working. In consistency it felt nothing like the glue-like latex version; it was thicker and more like natural peanut butter that needs stirring. We raced through the work while October treated us to a brief warm spell, which helped since Drylok needs temperatures above 50°F to adhere and cure properly.
Over two long days we applied a second coat to the walls and floor and two full coats on the ceiling, using eight additional gallons of Drylok. In total we used 13 gallons, which sealed our beige basement and gave us real confidence that the space is now weatherproof. After the first coat we had a week of rain and didn’t see any moisture seepage, and the second coat reinforced that the walls are protected for the long term. We chose the premixed tan color to soften the starkness of the space (Drylok comes in white, tan, gray, and blue), and while it’s not a dramatic color, it looks much better than raw cinder block.
The biggest win: no mildew. Even a week and two rainstorms later there’s been zero mold regrowth. That confirmed what the experts had said—the oil-based formula is superior to the latex version for blocking moisture and mildew.
With Drylok finally tucked away, we finished the last bit of painting prep: the concrete floor. We decided to use tan Drylok on the walls rather than painting latex over Drylok because once painted, surfaces can’t be re-Dryloked easily. Dryloking the walls preserves the option to reapply a moisture barrier in the future. The concrete floor, however, wasn’t our main moisture concern, so we felt comfortable painting it for color and durability.
To be resourceful we used leftover chocolate-brown porch and floor paint from a previous project (Valspar’s oil-based porch & floor paint in “Brownstone”) and applied one thick coat. The darker floor color will hide dirt and outdoor footprints—handy for a basement with its own outside entry—and helps the space feel connected to the rest of the house by echoing our home’s mocha tones.
This work is only the beginning of the larger basement overhaul. Once the floor paint cures we’ll tackle visual clutter such as the large water heater in the room’s center, plan built-in storage solutions, tidy access to the crawl space, and address other finishing touches. The goal is to complete this makeover before cooler weather makes working without heat uncomfortable.
We’d love to hear how you use your basement. Is it strictly storage, mostly ignored, finished living space with bedrooms or bathrooms, a man cave, or something out of a movie where monsters live? Share your basement setups and tips.
Side note: I mentioned this project to a friend who’s a construction pro (yes, at his wedding—bad timing) and his first question was, “You used oil-based, right?” I was glad to say yes and a little embarrassed about our first latex coat mistake. Lesson learned: for cinder block basements and mildew issues, oil-based Drylok is the safer choice.