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Floor for uneven, concrete basement floor

  • Last Updated:
  • Apr 11th, 2019 9:50 am
[OP]
Member
Mar 1, 2017
241 posts
46 upvotes

Floor for uneven, concrete basement floor

Hi,

My basement floor (concrete slab, sloping towards centre) is carpet, on foam underlayment. No vapour or moisture barrier, although thus far it has been dry.

I'm hoping to change it for something more durable, but still reasonably good looking. The best suggestion I've found on the interwebs is rubber. But all I can find is ugly gym floor. Any ideas or suggestions about where to source rubber tile, or another material that will work well? Leveling the floor is not an option as I'll lose too much height.

MT
12 replies
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Mar 23, 2008
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Edmonton
mikefly wrote:
Apr 8th, 2019 2:14 pm
Hi,

My basement floor (concrete slab, sloping towards centre) is carpet, on foam underlayment. No vapour or moisture barrier, although thus far it has been dry.

I'm hoping to change it for something more durable, but still reasonably good looking. The best suggestion I've found on the interwebs is rubber. But all I can find is ugly gym floor. Any ideas or suggestions about where to source rubber tile, or another material that will work well? Leveling the floor is not an option as I'll lose too much height.

MT
You might want to post what your intended purpose for this space is. Is it living space, that you're using daily? Is it a place you use to store your fallout shelter supplies? And what's wrong with the carpet?

Without some form of leveling, you'll always feel the bumps/ridges. The rubber tiles aren't going to be flexible enough to handle significant deviations, I don't think. The other issue you'll have with your proposed "rubber tile" solution is that it will trap moisture underneath, which could become a mold trap. You say it's been dry "thus far", but what does that mean? So far this spring? The last decade?

C
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Jan 28, 2007
2094 posts
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SW Ontario
Self Leveling Cement, and only enough to fill in the center dip.
[OP]
Member
Mar 1, 2017
241 posts
46 upvotes
The space is intended for the kids to play, to watch movies on a projector, and a space for guests to sleep over.

Trapping moisture is something I didn't think of, but is certainly a possibility and a good reason not to change out the carpet.

Aside from a leak when we redid the driveway and it was gravel-filled, we haven't had a leak in the basement of which I'm aware. Some neighbours a few hundred metres away have had issues.

MT

CNeufeld wrote:
Apr 8th, 2019 2:25 pm
You might want to post what your intended purpose for this space is. Is it living space, that you're using daily? Is it a place you use to store your fallout shelter supplies? And what's wrong with the carpet?

Without some form of leveling, you'll always feel the bumps/ridges. The rubber tiles aren't going to be flexible enough to handle significant deviations, I don't think. The other issue you'll have with your proposed "rubber tile" solution is that it will trap moisture underneath, which could become a mold trap. You say it's been dry "thus far", but what does that mean? So far this spring? The last decade?

C
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Mar 23, 2008
9332 posts
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Edmonton
So what's wrong with the carpet the way it is? And how uneven are you talking about? Is it just sloped, or is there cracks/bumps/ridges?

And I agree with the previous poster... Use enough self leveling compound to fill the low spots. Yeah, you'll lose some headroom in those low spots, but they were the low spots. It's not like you're going to lose an inch in the locations that are already high.

C
[OP]
Member
Mar 1, 2017
241 posts
46 upvotes
I think uneven is the wrong explanation. It’s not that there are lots of bumps and dips - it’s that it is all sloped towards the centre. It is possible the underlayment is hiding some low spots, but they are not terrible or I would have noticed them.

Actually leveling the floor would raise it 3-4” in places - in a 6’ basement, that’s a big deal!

As for the carpet - it’s cheap looking, stained and the underlayment has shifted so it’s no longer smooth on top.
CNeufeld wrote:
Apr 8th, 2019 4:26 pm
So what's wrong with the carpet the way it is? And how uneven are you talking about? Is it just sloped, or is there cracks/bumps/ridges?

And I agree with the previous poster... Use enough self leveling compound to fill the low spots. Yeah, you'll lose some headroom in those low spots, but they were the low spots. It's not like you're going to lose an inch in the locations that are already high.

C
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Jan 28, 2007
2094 posts
1427 upvotes
SW Ontario
mikefly wrote:
Apr 8th, 2019 5:40 pm
I think uneven is the wrong explanation. It’s not that there are lots of bumps and dips - it’s that it is all sloped towards the centre. It is possible the underlayment is hiding some low spots, but they are not terrible or I would have noticed them.

Actually leveling the floor would raise it 3-4” in places - in a 6’ basement, that’s a big deal!

As for the carpet - it’s cheap looking, stained and the underlayment has shifted so it’s no longer smooth on top.
Sounds like there is a floor drain in the center under all that carpet if that is the case.

If it is 3"-4" loss, just how wide an area is this as that seems a rather big difference
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Oct 15, 2007
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It’s probably sloped to a floor drain
Everything has been said before, but since nobody listens we have to keep going back and beginning all over again. - Andre Gide
Deal Addict
Aug 29, 2011
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Mississauga
My basement slab has lots of hills and valleys. I swear the concrete guys must have been hungover when they poured it.
Deal Addict
Nov 9, 2008
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Toronto
We poured a new slab and intentionally graded it very gradually toward floor drains. Laid LVP on it with no issues.
Newbie
Nov 2, 2018
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Pouring down self levelling cement is certainly not a DIY job for most people. If you want the contact for the guy who poured down self-leveller in my basement, DM me. Did it for half the cost of any other quote. Or.....just get new carpeting
Deal Addict
Nov 17, 2012
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Toronto
You say you have six foot ceilings - what is up there? Just the open joists or is there a finished ceiling?

The optimal thing to do is put a subfloor in to keep it warm and dry and then flooring. But, understandably if your ceilings are only 6 foot, you don't want to give up the couple of inches that would consume.

My 100 year old original (not underpinned) basement with a wood subfloor (1x4 sleepers, styrofoam insulation and 3/4" ply on top), 5/8" engineered hardwood and drywall ceiling directly on the joists is a few inches short of 7 feet. So I'm surprised when anyone has a basement that isn't as deep as mine.

You may have inches to gain if there is a suspended ceiling. If I was doing my basement again, I'd leave the joists open, clean up the electrical and plumbing, paint or dry-ice blast the joists to make them look good and leave it open.

Depending on the slope, you still might be able to put those 2 x 2 basement subfloor 'tiles' in which have the egg-crate plastic base and OSB top. Then put laminate or something on top of those. Drill a hole for the floor drain and put a nice looking cover over it.
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Deal Addict
Nov 17, 2012
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Toronto
BTW - now is also the time to have your drains inspected. When I was re-doing my basement bathroom, I had the old clay pipes snaked and scoped. Ended up digging up a chunk of the basement and putting new pipe under the concrete. No point in finishing over a basement that ends up needing to be torn up.

Removable click flooring and those wood subfloor tiles would make life easier if you ever need to lift the finished floor of course. Even better would be the tile carpet used in offices - this is why they do that, so they can replace small sections of flooring as needed.

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