Fixing a concrete floor

Problem: A 20 (?) year old concrete floor under pathetic carpet where the wheels on my office chair have quite literally worn a groove through the carpet and into the concrete.

So, how to fix this? Looking at the concrete, it seems to be quite powdery (poorly mixed originally perhaps)? Would the following work?

  1. Get up anything loose then apply concrete stabilizer.

  1. Fill ruts etc with mortar (PVA first to increase adhesion).

  2. Apply levelling compound (how thick ? )

  1. Put down "tougher" carpet such as office grade carpet tiles to provide some protection between the wheels and concrete.

So - is this a plan or is there a better way?

Thanks, Paul DS.

Reply to
Paul D Smith
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I'd lift the carpet, remove all loose debris, PVA washover, then use floor levelling compound.

Just done this in our staffroom, albeit a small patch rather than full floor, and it works a treat .. easy to use, easy to work with, dries quickly, hardens quickly, less than a weekend.

Reply to
Paul - xxx

a 1:1 mix of water:SBR applied by the bucket load (it is very penetrating unlike PVA) will harden the top layer (1/4-1/2" down at least) very effectively. Pour on and broom-brush and add until it cannot absorb more.

Brush out any puddles and leave to dry. Allow upto a week for the floor to fully dry before covering.

Then (later the same day or the next day):

Ruts could be filled with SBR modified mortar. 1:3 cement/sand mixed with

1:1 SBR:water (use less liquid than usual - SBR is a plasticiser). Mix a small amount of cement slurry with 1:1 SBR:water, brush into the ruts and before it hardends or dries, apply mortar. The result will be extremely strong and will not IME crack or fail easily.

I've done a lot of this, dealing with a problem subfloor. SBR is expensive, but you should be looking to get it at around £15/litre at worst (Builders' Merchants often list it at £40/litre but will come down to £15 with suitable arguing). Some bigger B&Qs stock it at the right price and internet purchase is an option (what I did).

HTH

Tim

Reply to
Tim Watts

Is that a slip for "around £15/5 litres" or is there a better variety of SBR than the stuff I've used?

See eg

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Reply to
Robin

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Yes - sorry - it was meant to be 5l.

Pleased to see screwfix and Toolstaion sell it now at a just about sensible price:)

Reply to
Tim Watts

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From your experience, about how much is required per m2 of concrete?

Thanks, Paul DS.

Reply to
Paul D Smith

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I did the bucket-and-pour over 20m2 - hmm, think that was about 5l SBR + 5l water (the dilution is not critical for this part of the job).

Might have had another half of a 10l bucket.

BUT that was over 10m2 of s**te "screed" that was basically 90% brown sand and bugger all else (I had cut out the broken parts and patched - the rest was attached but soft). Massive absorbancy and 3/4" thick.

The other 10m2 was a very hard screed which took up a lot less liquid.

I'd budget for 1 litre SBR doing about 3-6m2 depending on absorbancy. If you're going to do this, it's best to absolutely soak the floor once[1]. If you put a half arsed coat on, then it hardens, it will block the uptake of a second application.

[1] If it gets sucked up, of course you can add more, but do it straight away not 2 hours later. Watch out for holes - you might also think it is absorbing a lot, when it's just running down a crack - noticable round the edges.

The nice thing is this will not make it any worse and will almost certainly make it better - to what degree is a bit pot luck, but it worked for me.

HTH

Tim

Reply to
Tim Watts

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Many thanks. Guess what I'll be doing over Christmas :-(.

Paul DS.

Reply to
Paul D Smith

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