Should we repaint the foundation block before installing drywall in our basement to ensure proper sealing and prevent future damage?
Asked by Babett Edler 
3 weeks ago
Last Updated: November 2, 2024
We’re in the process of redoing our basement. We haven’t noticed any water or leaks, but we’re taking down the wood panels to inspect the foundation and put up drywall instead. We’ve already revealed one wall and found some greenish paint peeling and cracking on the foundation block. Do you think we should repaint the walls with a sealant or put up a plastic barrier before putting up the drywall?
It might be a good idea to drylock the walls before building and drywalling them. What do you think?
Eliminate the mold before anything else
The mirror was the only place where mold was found on the paneling. It has been removed completely. No mold was found on the actual blocks. I think it may have been a condensation problem caused by the mirror.
Great. I hope you’re not intending to directly attach drywall to the block itself.
We planned to reconstruct the wooden framing first, then install the drywall. However, we want to know if we should paint the block with some kind of moisture protection before adding the wood framing. There was mold present, but it was not on the back of the wood paneling; it was only between the front of the paneling and where the mirror was glued. Essentially behind the mirror.
It might be a good idea to apply drylock before starting the construction. I usually leave a gap of an inch or two between the wall and the block when framing a basement.
Dealing with black mold is no joke – make sure to wear a mask when you’re near it and get rid of it as soon as possible.
Na Wells, the mold was only on the paneling where they attached a mirror. It has been completely removed and there was no mold on the actual blocks. I’m guessing it could be a condensation issue due to the mirror.
Hey , just a heads up – avoid putting a vapor barrier directly on the concrete wall.
Hey , I saw your photo with black mold on the blocks. I know you’re familiar with it, but a family member of mine got really sick from black mold in their home – he ended up in the hospital! I just want to caution you about any mold, especially black mold spores as they are very dangerous.
Na Wells The mold problem was immediately addressed when we removed the paneling. The dark area in the picture isn’t black mold, it’s just unpainted block. I agree it does look dark in the photo. Sorry about the confusion.
That’s great!!! Mold can really take a toll on your health!! Best of luck with the renovations!
Na Wells Hey, the first thing we did was take down the mirror attached to the wood paneling with the plan to paint over it. But when we discovered the mold, we opted to demolish the wall to ensure it wasn’t due to a leak behind the panels. After taking down one wall, we decided to remove all the paneling and switch to drywall. This allowed us to inspect all the basement walls for any hidden issues. However, as I mentioned, the mold was only present on the front of the paneling between where the mirror was glued. We also cleaned the block just to be safe, which got rid of whatever was painted on it. So, our question is, should we replace the painted section or try something new?
Had some great questions! I suggest consulting with a moisture specialist for your space. In the past, I had concrete block basement walls painted with concrete paint and added a small bottle to the gallon for sealing. However, there are likely more cost-effective options available now that won’t lead to moisture issues. Consider getting free estimates from a few companies and doing some research on YouTube to handle household issues yourself without spending a lot of money.
Avoid putting up plastic, as it can lead to condensation and mold within the wall. Consider tuck pointing the cracks and sealing them with dry lock. Additionally, I recommend adding 1” foam board between the block and your wall for insulation and breathability.
Wow, thanks a lot for this incredibly useful information!
Waterproofing is best applied on the exterior of the foundation wall rather than the interior. If there is no water or moisture inside the foundation walls, frame the walls, add insulation, and a vapor barrier on top. Finally, install drywall.
So, I started by applying drylock, followed by using 1 inch insulation foam board and gluing it properly. Then I proceeded to put up my walls and installed electric wherever I wanted. After that, I rolled out insulation with the brown backing facing away from the drywall to act as a vapor barrier. Finally, I added the drywall and it looks beautiful.
Begin with an oil-based primer followed by drylok
Start by cleaning the walls, apply a water barrier to the basement walls, and build a 2×2 stud wall for the drywall. Finish!
Roll on 2 coats of dry lock using a 1.25 nap roller sleeve. Fill in cracks with tuckpoint caulk from osi
Definitely, drylock and 4 mil poly.
I’m not entirely sure what the right solution is, but our basement had a similar appearance. It was finished by the previous owners. We never experienced flooding, but there was definitely moisture leading to mold behind the finished walls with foam insulation. After extensive research, I felt lost because some sources advised against sealing the concrete due to its eventual breakdown from moisture. Additionally, finishing the walls would make it difficult to detect mold growth. Since our house is well-established, an exterior plastic barrier was not feasible. I also learned that exterior drain tiles are not very effective in preventing water damage and often lead to starting over.
The solution I opted for was installing a water vapor barrier with an internal drainage system and pump. This system allows water/moisture to pass through but collects it behind the vapor barrier and pumps it out of the house. This seemed like a better option than sealing the cement blocks and waiting for the sealant to deteriorate. We plan to insulate the walls using a combination of foam and fiberglass where the house meets the cement walls as a cost-effective measure. While I’m not certain if this is the best choice, it is worth considering since I found no recommendations for an internal drainage system around the perimeter with a vapor barrier. It’s crucial not to install a plastic vapor barrier without a means for the moisture to escape, hence the internal drainage system and pump. Disregard the notion that vapor barriers cannot be placed inside a house; this is only true if there is no way for the water to exit. This is why I believe that dry lock/painting the cement does not effectively address the issue, as it is ultimately influenced by natural elements and the passage of time.😊