Help with Hearth Issues

[MichaelJ]

Hello, so we had a wood burning stove installed in place of our Gas Fireplace, in October 2019. By the end February 2020 we had noticed that the front piece of hearth which they had installed was moving away from the back, so we raised this with the company we purchased from, who (long story short) ignored us for a bit, then said we'd need to deal with the installers, then after a long back and forth (mainly us constantly chasing them - and yes we appreciate by this point COVID was a factor in the delay), eventually the installers agreed to come out and remove the fireplace and reinstall. By this point not only has the front piece of hearth moved over 1cm forwards, but the back (tail) piece had also warped / bowed upwards and a hairline crack had appeared down it. They suggested that the movement was due to the cement holding the hearth in place failing / expanding due to damp. So we had some work done outside to divert water away from the external wall, a damp proof membrane installed in the chamber, and (again after chasing the installers for a long time) had everything reinstalled eventually in November 2020 (all work carried out was done at our cost - including paying them for new pieces of hearth and re-installation).

Now I am noticing that the grout in between the pieces of hearth is failing. This time they put in one front piece of hearth, and a tail piece split into 3 sections. One of the back sections has broken away completely from the rest (it's not particularly moved from where it should be but the grout is cracked / crumbling all around). And the grout right across where the front piece joins to the tail pieces also is cracked.

My question really is - Is there anything we can do? Can we just re-grout the hearth to keep it in place, or is this going to be the same issue again that our hearth is going to fail? Does anyone have any ideas why this might be, I can't believe it's down to damp over such a short space of time when we had the area treated and a damp proof membrane laid before re-installation. Is this just a case of poor materials used by an untrustworthy installer? Any help would be really appreciated! We were so excited and happy to get this installed originally, but it's now been over a year of stress and frustration since! Thank you!

 

[rwhite]

Do you have an overview pic of the whole area?

 

[vatmark]

I wonder if this is due to expansion and contraction due to the heat of the stove.

 

[MichaelJ]

Thank you for your replies. I've attached some more pictures of the fireplace, and 2 pictures of the hearth from back in March when we had the previous issue - the hearth warping and cracking. You can see there it was just one solid tail piece, so I'm hoping that because this time the tail piece is cut into 3, we wouldn't have the same issue? (there's more room for expansion / contraction)

@vatmark this is what I'm hoping, and could well be the case. I'm probably (hopefully) overthinking it just because of the issues previously we've had with the same installer. But might be nothing to worry about. Thanks again for the comment.

 

[moresnow]

What make and model is the stove? What is the floor under the tile and grout composed of?