Is staining concrete before laying wood or vinyl flooring a bad idea due to potential condensation and mildew issues caused by blocked pores?
Asked by Ella Macdonald 
7 months ago
Last Updated: May 2, 2024
So, we were considering staining our concrete floors and then putting wood or vinyl on top later. The worker at Home Depot told me that it might not be a good idea. He said that staining concrete can clog up its pores and prevent it from breathing, which could lead to issues like condensation and mildew. Can anyone verify this for me?
Haha, that’s a new one for me! I actually oversaw staining the entire floor of a 200×600′ dealership I worked on as the foreman electrician in my town, and it turned out really nice.
Hey, did ever get around to putting a floor over the stained concrete like they mentioned?
I’m not entirely sure about that project, but I’ve seen it done on other projects. I’ve never heard of it being a problem. And honestly, I wouldn’t rely too much on what Home Depot employees say. Most of them aren’t very helpful.
Haha, nope. Stain actually allows concrete to breathe, as do certain types of paint. On the other hand, regular paint fills pores and prevents breathing. Staining concrete is completely safe.
This is accurate when using a sealer that prevents concrete from breathing, such as paint. However, mixing it into the concrete is harmless.
They apply a sealant to concrete regardless of whether it is stained or not.
I’m a bit confused by their comments. I frequently paint concrete floors using water-based enamel, polyurethane, acrylic, or water-based epoxy.
I’m guessing he mentioned this because you’re considering putting a floating floor down the line? I understand his point, but I don’t necessarily agree. If your concrete slab is already sealed, then what he’s saying would apply to any house built on a slab🙄. When it comes to staining, though, I recommend using a semi-transparent stain
If you decide to go with wood flooring, it’s a good idea to use a vapor barrier. Staining might not come out evenly on a sealed concrete surface, especially if it’s been there for a while.
Do you know how old this concrete is? Is it a newer home or an older one? New concrete usually takes about a year to fully cure, especially if it’s in a basement. I would wait until it’s fully cured before staining it. If it’s older concrete, you might not have a moisture issue. To test, tape a clear 3’X3’ piece of heavy plastic to the floor for 48 hours. If the concrete changes color or condensation forms, you have a moisture problem. If it stays dry, you’re good to go. Reactive stains shouldn’t be an issue, as they chemically change the color without closing the pores. However, they may cause uneven color on older concrete. Non-reactive stain is more like paint and provides a consistent color, but it may cause issues like flaking or peeling. If you’re planning on staining for just a year or so, I would wait until you apply your finished floor. If it’s going to
He’s at Home Depot for a reason. Give an epoxy coat company a ring, and they’ll get you on the schedule for next week.
Big box employees just don’t have the expertise, which is why they’re not contractors.
My husband works with concrete and he confirms that you can stain existing concrete. Make sure to properly prepare your floor before applying any stain. Look into specialized concrete stain products, which might not be available at Home Depot, but you could possibly order through the Pro Desk.
Can we talk about whether it’s a good idea to put floors on top of stained concrete later on? I’m worried about what the guy at Home Depot said about potential moisture problems.
Russell, you probably wouldn’t have issues with moisture if you seal the concrete after staining. However, tile might be a problem because the thinset might not stick properly to the sealant.
We’ve personally used floor paint on all our basement floors to control dust until we can afford laminate or carpet. It’s always worked well for us in the past, even after moving multiple times in 40 years.
Hey Kristen Zdonczyk
Kristen Zdonczyk