Hearth

[ukcat]

Hi I'm in the process of fitting an inset stove. I have a thick concrete constructional hearth but need to raise it by about 30mm. The stove will then sit on this hearth. I've read up and my stove (as per most inset stoves) can heat the hearth to over 100 Deg so I'm just concerned over what material to use to raise the hearth.my initial plan was to use a sharp sand and cement mix for this but will the heat cause it to deteriorated.ive added a pic to show the current hearth. The bricks are roughly placed to show where I will be building the enclosure up to create a smaller opening and where the Trowell is will be the base for the stove when uve decided on the best product to use. Any advise will be very much appreaciated

[markc]

Damp Sharp sand and cement will work well.

[ukcat]

1 hour ago, markc said:

Damp Sharp sand and cement will work well.

Would this be ok for the whole area ie even under the stove 

[markc]

43 minutes ago, ukcat said:

Would this be ok for the whole area ie even under the stove 

Yes, absolutely fine under a concrete, stone or slate etc. hearth. I wouldn’t ‘cast’ the hearth surface using just sand and cement but definitely ok under a solid hearth. If you don’t have a hearth to fit then cast in concrete and top with tiles or similar.

[ukcat]

8 minutes ago, markc said:

Yes, absolutely fine under a concrete, stone or slate etc. hearth. I wouldn’t ‘cast’ the hearth surface using just sand and cement but definitely ok under a solid hearth. If you don’t have a hearth to fit then cast in concrete and top with tiles or similar.

Yeah what's there already is solid concrete but the level is too low and therefore I need to add another layer to raise it up by about 30mm and I was concerned that I might need to add some sort of heat proof layer 

[crispy_wafer]

If you are unsure go to vitcas and see any products that might suit.

[ukcat]

38 minutes ago, crispy_wafer said:

If you are unsure go to vitcas and see any products that might suit.

I've checked it out and they have a heat proof render that is suitable.however I only really need the heat protection in the recess so would like to try and use normal mix on the front area but not sure whether putting it in as 2 separate parts is the best option or whether it would be better to do the whole area in the same product

Edited April 26 by ukcat

[markc]

4 hours ago, ukcat said:

Yeah what's there already is solid concrete but the level is too low and therefore I need to add another layer to raise it up by about 30mm and I was concerned that I might need to add some sort of heat proof layer 

Ahh, looks like I misunderstood, I thought you wanted to put something under a hearth to raise it, hence the almost dry mix. If you are putting it on top then mix more like concrete or stiff mortar and compact it down well. Compact/tamp using a piece of timber or board and a hammer or mallet.

[ukcat]

12 hours ago, markc said:

Ahh, looks like I misunderstood, I thought you wanted to put something under a hearth to raise it, hence the almost dry mix. If you are putting it on top then mix more like concrete or stiff mortar and compact it down well. Compact/tamp using a piece of timber or board and a hammer or mallet.

Wondered if it would be possible advisable to basically put the top layer in in 2 stages or use normal sand and cement for the front area and use a heat proof render for the rear (smaller area) it will all then eventually be tiled but wondered if better to just do it all at once in the same material 

[markc]

1 hour ago, ukcat said:

Wondered if it would be possible advisable to basically put the top layer in in 2 stages or use normal sand and cement for the front area and use a heat proof render for the rear (smaller area) it will all then eventually be tiled but wondered if better to just do it all at once in the same material 

If you are tiling over anyway then sand and cement is fine, the render stuff is likely to be cement and a high silica sand similar to fire cement. 

Edited April 27 by markc