I have a concrete floored crawlspace which I’d like to do an epoxy finish on but the concrete pour is pretty bad in spots. It’s soft, dusts terribly, and can be scratched with a fingernail in some areas. Before I resign myself to grinding or cutting out areas and repouring them I’d really like to get some opinions about whether that’s necessary. I kinda think I already know the answer but maybe you folks have better ideas (hopefully).

I have some concrete hardener I haven’t tried on these areas yet but I suspect they’re too bad even for that, but maybe not.

Video here (this sub doesn’t allow video posts I guess, or maybe I didn’t see the option, posting from my phone):

Acceptable-Start2

1 | 9 hours ago

That’s incredibly weak concrete by design because it’s cheap and doesn’t need to be strong. What’s the purpose of coating it?

Budget-Ambassador203 [OP]

1 | 9 hours ago

Makes sense, doesn’t need to be structural, but I think this was mostly just from a bad mix/pour as a lot of it is at least strong enough that it doesn’t scratch or dust, this weakness is only in a few spots (pretty large spots, maybe 30-40 SF total spread across different pockets, but not the whole floor).

I’d like to coat it because we use it as a storage area and I’m in and out of it all the time. It’s a pretty high crawlspace (like 42”) so I have a ton of stuff stored in there and would like it to be a clean space. Partially the motivation is to stop the dusting but I think I have to fix that before I can even coat it.

I really just want it to be a place we can go into without worrying about getting dirty.

Acceptable-Start2

2 | 7 hours ago

I’ve done repairs in crawlspaces, the nicest ones to work in had gotten super cheap carpet and laid it on the floor, not necessarily under bins and boxes and stuff but in the “aisles” the carpet makes it easier on the knees too.

Budget-Ambassador203 [OP]

1 | 7 hours ago

I’ve been in a few with carpet scraps too, definitely easier on the knees! I made a couple rolling carts though and I like using those to move stuff around and I want a smooth surface for that.

Plus we get mice occasionally and I think carpet might just get kinda gross over time. Working on sealing everything, foamed the sill plates and all penetrations so they’re mostly kept out as far as I can tell, but winter will be the real test.

Maybe a really thin pile carpet is the in the future, that’s not a bad idea.

ihaxr

2 | 6 hours ago

Look into getting it encapsulated, they roll out these rubber mats on the floor and walls. I had it done at my old house before I sold it and I would’ve slept down there it was so cozy afterwards.

[deleted]

2 | 10 hours ago

Budget-Ambassador203 [OP]

1 | 9 hours ago

Thanks, I appreciate it! This is what I suspect too but just want to see if anyone has dealt with this or has any other suggestions/insight before I go that route (not really looking forward to the grinding and patching hah).

[deleted]

2 | 9 hours ago

Budget-Ambassador203 [OP]

1 | 9 hours ago

Definitely not the funnest job. I did the whole basement with a 7” angle grinder already (should’ve just rented a unit) and have all the dust collection stuff but it’s still just not a great job.

You’re right, I’ll throw down the hardener in those spots and see if it does anything.

Honestly I probably have to grind the crawl anyway before epoxying I was just trying to avoid cutting and repouring whole sections. I think the pour might be bad all the way through in spots, like they watered down the concrete way too much to get it flowing, and the crawlspace slab is an inconsistent thickness and has a plastic vapor barrier embedded in spots (there’s a spot where a little bit is sticking out of the concrete). So patching is almost definitely in my future.

Thanks again for your insight, I appreciate it.

Epoxy over bad concrete?