How to seal a crumbling concrete floor?

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insane

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#2937968 3-Jul-2022 19:56

tweake:
self leveling will have the same issue. its to thin.

you either do a thick enough pad on top, or just rip the old concrete out. if its falling apart that much its a fairly straight forward job.

Well ripping it out completely is out of the question for now. It's supporting one room above it.

The slab is probably 20-25cm think, and has no other cracks in it that I can tell.

I could try self-levelling compound and put ply or Vinyl over it. I've used it before and it's fairly strong but does crack if too thin - it was quite expensive for just a small tub of Dunlop so hopefully it comes in bulk.

I do have a few bags of Portland cement I had planned to use for a different job. Do you think I could wet the floor and create a slurry with that and add those fibreglass pieces they use to add strength to concrete?

tdgeek

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#2937969 3-Jul-2022 19:58

blackjack17:

Wouldn't it be easier simply to put a false wooden floor over the top? 18/20mm ply leveled with some 10mm strips underneath?

Perhaps but if you glued it, it will come away from loose stuff. Same if you screwed it. I like the idea of a layer of levelling compound/expoxy to stabilise it.

insane

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#2937970 3-Jul-2022 20:00

tdgeek:
Would pouring epoxy over it not provide a good base? As in it will bind the existing concrete?

That was my initial idea, I've seen a few YouTube folk epoxy their garages (granted on a good substrate), so assuming I could get enough of it cheaply I'd give it a go! I like the idea of a smooth surface that's easy to keep clean.

blackjack17

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#2937977 3-Jul-2022 20:35

tdgeek:

blackjack17:

Wouldn't it be easier simply to put a false wooden floor over the top? 18/20mm ply leveled with some 10mm strips underneath?

Perhaps but if you glued it, it will come away from loose stuff. Same if you screwed it. I like the idea of a layer of levelling compound/expoxy to stabilise it.

Few dynabolts will hold it in place, plus the weight of the timber and benches.

What ever he does it will be lipstick on a pig, replacing the slap will be costly.

Hell even just gluing down a layer of vinyl would be better than nothing. Will stop the dust.

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insane

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#2938646 5-Jul-2022 20:59

I'm going to try something for kicks and giggles to begin with before going further:

1. Will test a can of CRC spray on glue over a small spot and see if that will lock the powdery layer down.

2. Test a small amount of concrete slurry to act as levelling compound.

3. Test a bit of epoxy resin.

I think you've all confirmed that covering it up is the best approach, so will do my best to get a level surface and hide it / lock it in with Vinyl or similar as I can manage jacking up the benches etc to get a roll under them all. Just wish I had done it years ago when I first moved in.

Thanks for your help!

itxtme

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#2938703 6-Jul-2022 09:17

insane:
I could try self-levelling compound and put ply or Vinyl over it. I've used it before and it's fairly strong but does crack if too thin - it was quite expensive for just a small tub of Dunlop so hopefully it comes in bulk.

Buy it by the bag not premixed. Either tile shop or Bunnings Mitre10. Feel like bunnings Cemix was the best priced one when I was doing heated tile floors last year

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