Hearth removal, how to level floor?

moonpenny

How do I fix (level) this floor after having marble hearth removed?


It is only 100 cm x 35 cm so too small to get someone in to do it.
It is almost level with floorboards both ends though cracked, and dips in the middle so front floorboards are roughly15 mm higher in middle.

I will be laying carpet so doesn't have to be great but no obvious bumps or ridges etc that will be noticeable through carpet after a bit of wear.

I have looked at self levelling compound or some sort of concrete repair but unsure which would be best.
Also, they come in 20kg bags and most need a prima as well so end up really expensive for just a small job. Can I get smaller quantities anywhere?

Am also very confused about the different sorts of primer etc for different materials. 
Would a cement stick to old cement without a primer?  HELP!!!

silvercar

Just a word of warning. I had similar, someone had laid a carpet over it. I stepped on it and it cracked broke and my foot fell into the void. Twisted ankle.

stuart45

silvercar said:

Just a word of warning. I had similar, someone had laid a carpet over it. I stepped on it and it cracked broke and my foot fell into the void. Twisted ankle.

Was it an upper floor hearth?

Eldi_Dos

If it is going to be underlay and carpeted I would not be spending too much time and effort on that.

Clean with a hand brush and get rid of any small particle's then fill in gaps and around broken pieces with a tube of filler. Once that has dried and set just put a couple of sheets of newspaper over the concrete bit before underlay and carpet go down.

Fitting a gripper you should be able to catch it on the floor boards either side but if you wanted a bit of adhesive where it goes across heath would not go amiss.

silvercar

silvercar said:

Just a word of warning. I had similar, someone had laid a carpet over it. I stepped on it and it cracked broke and my foot fell into the void. Twisted ankle.

stuart45 said:

silvercar said:

Just a word of warning. I had similar, someone had laid a carpet over it. I stepped on it and it cracked broke and my foot fell into the void. Twisted ankle.

Was it an upper floor hearth?

Yes, upstairs. The fireplace there had been removed years ago. Had a new kitchen fitted with RSJs downstairs, though left the fireplace and chimney in another room untouched, so there shouldn’t have been a problem. RSJ was sized and positioned by a structural engineer, so he must have been unaware that there was a hearth upstairs under a carpet that needed supporting.

moonpenny

Silvercar, you had me worried but I think it will be pretty safe as it is ground floor.  The concrete seems pretty solid.

moonpenny

Eldi_Dos said:

If it is going to be underlay and carpeted I would not be spending too much time and effort on that.

Clean with a hand brush and get rid of any small particle's then fill in gaps and around broken pieces with a tube of filler. Once that has dried and set just put a couple of sheets of newspaper over the concrete bit before underlay and carpet go down.

Fitting a gripper you should be able to catch it on the floor boards either side but if you wanted a bit of adhesive where it goes across heath would not go amiss.

Thanks Eldi_Dos, your suggestion sounds good.

I was over thinking it and it was becoming too expensive and complicated. 
Will a filler stick to the old concrete? That was the main thing I was worried about.

You mentioned putting newspaper down afterwards, well I was thinking about covering the whole floor with a roll of thick paper (I think builders use it in order not to mess any newly decorated floors)
I used similar years ago and it stopped any dirt and draughts coming up from old floorboards.

Maybe, I could ask carpet fitter to use "no nails" or similar to to stick gripper to that area of floor!  Just thinking aloud!!!

stuart45

moonpenny said:

Silvercar, you had me worried but I think it will be pretty safe as it is ground floor.  The concrete seems pretty solid.

Ground floor hearths are usually reasonably solid, as they should have brick render walls filled with hardcore under them. Upper floors are not as solid. The concrete hearths are usually reinforced and built into the wall, or sometimes have a brick arch from the wall to the trimmers to take the concrete. Some of them are now past their sell by date and are better removed.