First floor concrete hearth repair

[bobo29]

Hi all

First floor bedroom previously had a fireplace (removed a long time ago) and the concrete hearth was broadly level with the floor and was previously carpeted over.

I’ve noticed that a part of it was cracked and not lying totally flush with the surrounding floor so I’ve removed the damaged part (carefully as I don’t know what it contains). Have attached photo.

What would people advise as the best way to repair this damaged section? Once complete I would be fitting carpet and underlay. I don’t fancy using a standard concrete as I don’t know how secure the frame is in the event something were to drip through.

Someone on another forum used repair mesh and premixed fire cement. Is this thicker and less likely to drip through the frame in the event there is an imperfection with the frame? Any other suggestions? Underneath the removed section the concrete isn’t totally flat so I don’t think it would be easy to lay wood without removing even more concrete.

 

[foxhole]

Just mortar mix thick enough to not drip thru any gaps.Or dig it all out and put in timber .

 

[Burnerman]

As above, these hearths were traditionally cast into the wall with timber bearers underneath - a sort of a cantilever effect.
A stiff mortar mix to replace the existing failed screed will be fine.
John

 

[dazlight]

Dig the top layer out the prime and use a smoothing compound like ardex NA