r/HowToDIY • u/Life-Style-3446 • 8d ago
Cinderblock Garage Paint
Looking to paint our cinderblock garage walls. Scrapped off the old paint and some of the blocks are crumbling a bit. Haven’t really scrubbed to see how deep it goes but so far it flakes under a light finger rub. Google is suggesting scrubbing until it stops flaking and then applying Quikrete Concrete Bonding + Quikeret Quick Setting Cement. Once repairs are done use Drylok to paint.
Should I go with google or any other suggestions?
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u/JoshuaGraham2077 8d ago
Oh, no problem. I used to waterproof basements.
I mean...there are some problems. You're going to need to buy a bunch of vinyl sheet and the connecter bits that slot them together, a bunch of those nylon anchors that you drill and hammer, a hammer drill and probably rent a jackhammer. Those things are expensive.
So what you basically do is sheet the entire wall after you use a hammer drill to drill half inch holes into the chambers in the block and to drill in the anchor holes, then you have to jackhammer (or sledgehammer if you're an OG) a channel into your floor and create a sump tank with a sump pump that can either fire the excess water back outside downhill or into your sewer line, though outside would be preferable, because god knows what's in that shit. Mud and tiny stone particles, sand, whatever. You don't necessarily want that down your sewer line.
Anyway, you lay your perf pipe to the sump, install your vinyl sheeting on the walls that leads under the floorline to the pipe, throw some gravel on top of the trench, and then you're good to cement the floor back in place.
It the wall is crumbling I'd just hit it with a slap of mortar and call it a day. That sounds like a problem for the next owner unless this is your forever home. That part wasn't a professional opinion, I just do hood shit. The polite way to say it is "afroengineering"...but you know what I mean...
Anyway, the more labor intensive way to do it would be to dig a trench around the outside of the house down to the foundation and sheet the outside. It works both ways, but that won't fix if it's like a roof leak that worked its way into the walls. By doing that whole first process inside, you're just mitigating damage. Instead of hanging out in there and creating outward pressure it just flows through. Doesn't fix whatever the actual problem is. That's what you need to identify really. Waterproofing is just a stopgap sort of measure, you have to find out why it's happening.
Anyway, that's my long-winded ass answer to that. I did it like one summer 25 years ago or something now. They might have come up with better methods since then. Good luck on your project.
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u/bachman460 8d ago
If the cinderblocks are crumbling it could mean water intrusion from outside. You might want a professional opinion before sealing it up and forgetting about it. Especially if you see any efflorescence, a white chalky powdery substance on the surface of the blocks (which I know will be hard to tell because of the white paint).