Cracks in concrete floor

sjoh0961

warmhands.coldheart wrote: »

Chances are there may be no DPM under the concrete so leading to rising damp. Also in olser houses the cement/screed floors don't tend to be as thick as they would put in now-a-days and also sub-base of compacted stones/hardcore which is usual now-a-day wasn't always put in in those days either especially where sub-soil was clay.

Personally I'd rip the lot up but then it will cost but in the longterm if you put insulation etc in when re-instating you could make the money back..

How much do you think that kind of thing would cost?

Do you think it sounds like the sort of thing we can just live with?

sjoh0961

RDG wrote: »

With the cracks and joints it may be ok to just seal them up with a reasonable thin sealant, like i said a high visocosity resin would be ideal - but the floor needs to be dry at the time of sealing or it wont work. This will prevent water to the surface but it will still get in the cracks. Seen as the floor was dry when you moved in I dont think that is a major problem.
A resin system is probably over kill so a water based resin floor paint will probably do the trick as long as it is thin enough to penetrate the cracks and joints.

By raised up what do you mean?

I mean that the concrete on one side of the crack is a few (maybe 4 or 5) mm higher than on the other side. This crack is probably about a foot long. Whereas, with all the other cracks, there is no difference in level.

RDG

Whereabouts on the floor is this? Is there any damp around the crack?

Is it a crack or a joint?

sjoh0961

RDG wrote: »

Whereabouts on the floor is this? Is there any damp around the crack?

No sign of damp near this crack. It's in the hallway, probably about a metre from the front door, near the entrance to the lounge, so about 6 inches from what appears to be the edge of the slab.

sjoh0961

Hopefully I have attached some photos, not sure if they're any use. Two show the cracks, the other shows where the fireplace was.

sjoh0961

RDG

The crack about a metre from the front door probably means that the foundations upto the door from that point were lower during construction so at some point it cracked. How sharp is the top edge of the crack?

The bit in front of the fire place looks like 2 seperate additions to me. The large square cloest to us and then the thin strip against the wall. My suggestion will work fine as the concrete looks good and doesnt appear to have any other defects. You will need to wash the floor and try and get any stuff out of the cracks and then piant over the cracks. That will seal them and prevent water ingress for a good while.

warmhands.coldheart

sjoh0961 wrote: »

How much do you think that kind of thing would cost?

Do you think it sounds like the sort of thing we can just live with?

I think what you do depends on how long you see yourself in this house. The House I'm renovating will be (probably) my "house for life" if there is such a thing, so I bit the bullet and dug out the whole ground floor and am having it replaced (costing just over £5500) but I'm in Northern Ireland and doing a lot of the donkey work myself at weekends.
My brother and myself dug out the floors and put in the hardcore subbase. Leaving builder to do the concrete slab, DPM, insulation, and screed.

If money is tight or you don't see this house as one you'll be in for the long term, maybe just stick with the shorter term fix...

sjoh0961

warmhands.coldheart wrote: »

I think what you do depends on how long you see yourself in this house. The House I'm renovating will be (probably) my "house for life" if there is such a thing, so I bit the bullet and dug out the whole ground floor and am having it replaced (costing just over £5500) but I'm in Northern Ireland and doing a lot of the donkey work myself at weekends.
My brother and myself dug out the floors and put in the hardcore subbase. Leaving builder to do the concrete slab, DPM, insulation, and screed.

If money is tight or you don't see this house as one you'll be in for the long term, maybe just stick with the shorter term fix...

Blimey, that all sounds a bit hardcore. I'm hopeful that it won't come to that, as I think it would cost a fair bit more in London, and we're living here.

Good luck, though

tony6403

Apparently depends on where you live, but you might want to have a look at this document.
Sulfate damage to concrete floors on sulfate-bearing hardcore
https://www.communities.gov.uk/documents/.../pdf/703049.pdf