filling drilled hole in concrete floor. HELP!

17 Nov 2005
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United Kingdom
Ok I drilled 10mm holes into my downstairs cloakroom concrete floor in wrong place. I am sure I measured it right. So I remeasured and the correct position is alongside the hole I drilled. As it is next to it I have weakened the hole where I would push the raw plug in to hold a the frame of a wall hung toilet frame so a long bolt screw would be holding it firmly to the floor.

What can I use to fill both holes and start again? Drilling into the one hole I have filled? It has to be a liquid cement something runny to fill the 10mm hole. I have been to my local builders yard and they sell alsorts of cement. Also in tubs where you mix a bit of water. It has to be the right consistency to flow into the drilled holes ready for redrilling so this means they have to be solid to redrill to hold the raw plug. Or is there an alternative to concrete cement as they are only drilled holes about 8cm deep. Please any suggestions? Thank you. :rolleyes:
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8cm deep? That must be a heavy loo! You can fill with many things, just push in as much as you can. Once filled you can push a plug in and save more drilling.
Smileysmile, Hi.

You could consider filling the holes with something like, car body filler? but this tends to be quite thick.

How about an epoxy resin? that is a bit more fluid? BUT it is imperative that any dust in the original holes is removed, this can be achieved by the use of a bicycle pump or similar, if you do not remove the dust, the resin will not grab and bind with the concrete floor.

I'm not an expert but I would use epoxy resin mixed with some sand. Add just enough sand so it's still fairly runny and will flow into the hole.
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Thanks guys. Yes 8cm deep. It's a Geberit frame for holding a wall hung toilet that doesn't sit on floor. I need to refill with concrete. Push it down there and bind with existing concrete. The correct holes are drilled. The incorrect holes are next to them with a very thin wall separating them. So if I fill the incorrect hole with something solid then when I place the raw plug in correct hole the thin wall won't crumble. Get me? Ok I am uploading a photo.

Correct hole now drilled but need to refill the other one. That needs to be solid so when I push raw plug in correct hole and tighten screw but then it will be solid and not crumble. Any suggestions please? :rolleyes:

I could put a dowl in correct hole then fill incorrect hole with cement slide out dowl and wait for cement to set?
I'd go with the Epoxy suggestion, I've nothing but good experiences with re-drilling next to areas I've had to fill with epoxy.
Smileysmile, hi again.

Having now seen the two holes, how about finding a length of Dowel same diameter as the hole, but a lot longer, wrapping it in a bit of cling film or similar, enter it into the good hole and fill the un-wanted hole.

Allow all to set, withdraw the dowel, it should come away clean with the cling film protection and carry on?

or you could just cling film your plug directly into place in the filler and save more drilling
10mm dia holes, 80mm deep? :eek:

The frame rests on the floor - what kind of lateral forces does it transmit?
Why not fill it with concrete? Or rather just a strong mortar mix.

Not only is it cheap and easy but it also will match the existing floor.
lol thanks for all your comments.
The dowel suggestion is good but i am maybe swinging towards filling with smooth cement push it down to fill both holes and start again. Will it be just as hard as the existing concrete?? So when I redrill it won't be soft like drilling through thermalite blocks? So many cement/mortar mixes out there I am confused? :rolleyes:
The mistake people make when assuming that a repair (with water based products) will be as good as the original, is the way the repair binds to the existing.

A large body of concrete or mortar will have a fair bit of water content which is vital in the curing process and is the lifeblood and strength giving addition to any cement based product.

You would need to thoroughly damp down the hole and try and keep it from drying out too quickly otherwise your concrete 'plug' will be useless.

I would suggest using a strong gritty (not gravelly) screed type sand mix, if you do decide to repair with a 'wet' product.

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