Using Oil-Based Drylok To Block Mildew & Seal Cinderblocks

Ok, we’re back on speaking terms with the basement. After it gave us quite a hard time when we began our Dryloking-interrupted-by-oh-no-is-that-mildew adventure (read all about that right here), we’re feeling victorious after conquering the first step towards turning our cinder block insect shelter into clean and functional storage space.

If you recall, we had already faced the grueling disappointment of mildew spots making their way through our first coat of white latex-based Drylok (which is like painting with Elmer’s glue, btw)…

So with our second round of bleach-treatment having tamed the mildew a bit more, we crossed our fingers as we broke out the powerhouse oil-based Drylok (as recommended by the experts at True Value for being even more protective and durable).Talk about stinky. Sheesh. Thank goodness for our professional grade gas masks (we’ve read about people passing out without them when it comes to the oil-based formula). When it came to the consistency, it was like we had traded Elmer’s glue for natural peanut butter (you know, the kind that you have to stir to mix the oil in?). But we furiously trudged ahead as quickly as possible while October graced us with a convenient little “heat wave” last week (Drylok has to be applied at 50+ degrees so last week’s highs in the 70’s were a blessing to our otherwise unheated basement).

After two 5-hour days and eight additional gallons of Drylok (yes, eight!) we finally finished slathering a second coat on the walls and floor plus two complete coats on the ceiling. And with that we officially sealed our beige box of a basement (yup, that’s 13 gallons all together, totaling 325 beans- thank goodness for our True Value gift card!). And a few hundred bucks is still a small price to pay for a weatherproofed basement that can now serve as usable storage forevermore (in fact after the first coat we had about a week of rain and nary a drop of moisture seeped through, so the second coat convinced us even further that our basement was completely waterproofed for the long haul). And despite the premixed tan Drylok color being a little fleshy for our tastes (they offer it in white, tan, gray and blue- we went with tan to make it feel a bit less stark down there), it actually looks pretty good- especially compared to the raw cinder block “before.”

But the best part by far is no mildew (!!!) – even now, a week and at least two rainstorms later. Zero. Zilch. Nada. I guess the guys at True Value were right… that oil-based stuff is way better than the latex version.*

So with our Drylok finally packed away, this weekend we took care of the last bit of painting prep: the floor. See, we opted to use tan Drylok everywhere instead of painting with tan latex paint over white Drylok because painted Drylok can’t be re-Dryloked, which is recommended every 15+ years or so. But we wanted to bring some color to the floors to break up the big beige box of a basement (all of our moisture problems stemmed from the porous cinder block walls, not the concrete floor, so we’re confident in painting over it without worry that we’ll need to re-Drylok the floor in a decade or two).

And in the spirit of being cheap using what we have, we broke out some leftover chocolate brown porch and floor paint from our sunroom floor-painting project (Valspar’s Oil-Based Porch & Floor Paint in “Brownstone” in case you’re wondering), slapped on one thick coat, and called it a day. We love that the dark color will hide dirt and outdoor footprints (since it’s a separate entry basement that’s always a plus because we’ll always be trudging in from outside) and we also appreciate that the rich tone works with the rest of our home’s mocha flooring to make it feel like a part of our casa, even if it is a bit disconnected.

But of course this is all still just the beginning of the big basement overhaul. Once that floor paint has a few days to dry, we’ll be back in there planning how to minimize eyesores like the big water heater in the middle of the room, brainstorming some storage solutions, tidying up a few more areas – including the access to our crawl space – and hopefully finishing this basement makeover before the whole lack-of-heating-down-there thing really makes this project uncomfortable.

Oh and while we’re on the subject, tell us what you guys use your basements for. Are they storage only? Completely abandoned? Livable square footage with extra bedrooms and bathrooms? Man caves? Rooms where monsters live like in Home Alone? Spill it.

*I also mentioned our basement project to my very-expert-in-construction friend last weekend (at his wedding – I know, great “you just got married, but let’s talk about Drylok” conversation skills on my part). First question he asked was “you used oil-based, right?” I quickly responded “of course,” too embarrassed to admit our first coat mistake. Lesson learned.


  1. says

    We don’t actually have a basement, but we do have a walk-in crawl space. We’ve been thinking about “finishing” it off sometime in the near future – at least sealing off the floor so it is more than just exposed dirt, and maybe adding some storage space so that we don’t have to come up with creative ways of storing things like our wet vac, air compressor and other large items (right now our guest closet is home repair central… nice thing for our guests to see when they open the closet to hang something up!) I also like the idea of sealing it off because, well, I hate little critters like the spiders that are so rampant in South Carolina and I would love to have an area that I could keep on top of webs and stuff a little easier. Anyways, love what you are doing with your basement, it is looking fantastic!

  2. Katie says

    What a difference! It looks great already, especially with the beautiful floor color.

    We don’t have a proper basement, but the ground-level floor of our house is the garage. There’s a storage area at the back (I don’t know the exact dimensions, but I’m guessing 8 feet wide by however long a 2-car garage is). We moved in six weeks ago, so currently it’s just filled with Christmas decorations and bikes, etc., but we have plans to finish it out and maybe turn it into a very skinny exercise room with some weights, an elliptical, and a TV.

  3. CarMaj says

    It looks amazing already! I am a bit jealous becasue I wish we had a basement… we have a crawl-space and it seems to work ok for now with storage… You are doing a great job!!

  4. Sandra says

    Our basement is essentially our den. We’ve got our computers down here, the TV, couches, and exercise equipment in the “main room.” Guests are hardly down here, so I don’t feel as pressured to keep it in pristine condition and instead we get to focus on comfort. No knick-knacks to dust or impress guests with!

    We have room for a bathroom down here, which we hope to build soon. Our laundry room and workshop are also down here, behind doors.

    I think I’d like to have a finished basement in all my future homes.

    • cyber terrapin says

      I am with Sandra. As long as the basement is reasonably dry (minimal water encroachment with a dehumidifier), it is the perfect place to do day to day living. This includes office, hobby, man cave, and dressing room. All of that living that can get messy and it is inconvenient to abandon what you are doing and tidy up because the world calls. The drawback is that it can be difficult to heat in the winter, but cooling is not necessary unless you get a long heat wave.

      Many people have entered my basement and said, “You really should finish this!” Well, IT IS A BASEMENT! When I am down there, I am so focused on what I am doing I don’t notice the cinderblock and floor joists. Plus, leaving it unfinished allows you to keep an eye on the plumbing and services while allowing you to spread out as you need to, like tax time and season changes.

    • says

      Rebekah- You caught us. John actually wrote the post a few days ago and yesterday I snuck in and took pics since the floor was finally fully dry. It feels like a totally different room already!

      LauraC- Yup that weird little wooden trap door in the wall next to that terrible water heater is the entrance to our crawl space which runs under the rest of the house. It’s a pretty big design challenge (especially with that old taped up water heater) but we’ve got a few ideas that just might work. Stay tuned…


  5. Liz says

    I can’t believe how much better it looks with that Drylok and paint on the floors! What a difference it made.

    Can’t wait to see what you do with the water heater.

  6. Carmen says

    Our basement was finished by the previous owners in a very rustic style. Pine plank ceilings and doors with wrought iron hinges and latches. I personally think it’s what sold my husband on the house. He has his “lovely room of death” (Ace Ventura)full of stuffed and mounted wild life down there along with our home theater system and playroom. My only gripe is that there was no bathroom put down there. So we have the toilet stump thingy (that’s the technical term) sticking up out of the floor between our computer desk and filing cabinet. Putting a bathroom down there now would require a lot of tearing up and expense and we don’t plan to be there more than another five years anyway, so we just trudge back upstairs whenever nature calls.

  7. Ellen says

    Looks great! I really like the addition of the chocolate brown – makes it look like living space.

    Our basement is 2/3 finished, with a 3-piece bathroom, open living area, and a nook (finished with closet) that just needs to be closed off to make a fourth bedroom.

    The unfinished-ish 1/3 houses a very functional and not too unattractive laundry room, as well as a storage/workout room.

    We love the functionality of the basement and are slowly making adjustments to up its use and attractiveness. Basements are wonderful things!

  8. says

    We don’t have a basement – hence the need for creative, OPEN storage ideas (we don’t even have an extra closet – just two tiny bedroom closets). We are thinking of turning our detached garage into some kind of organized storage area instead of having it hold our cars. We’ll see. I am excited to see what you come up with for your basement – maybe we can “borrow” a couple of your ideas! :)

    Oh, and our dogs would definitely want to be friends with Burger – especially Rufus – I think they might be related…we should introduce them if you’re ever in the K.C. area…..maybe they are third cousins or something! :)

  9. LauraC says

    WOW!! Looks fantastic now, esp with the mocha floors! The duck tape covered water heater made me smile though. With the rest of the room so nice it does stand out a bit more than it did. :=) Is that your crawl space beside it?

    As far as basements go though, ours is a mix of unfinished workshop, storage, laundry and mostly-finished family room. There is one door that opens up to the outside, and the last two weeks we’ve battled a flooded porch area which lets water flow under the door and on into the basement. Not fun. We think we’ve jerry-rigged a temporary solution (painted plywood “roof” over the porch + steps), but we might have a big project for this next summer if drainage really is the problem. But I still love our house!

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