Fixing constructional hearth/ fitting a granite one

[norahclare]

(On the boyfriend's insistance) We are fitting a solid fuel burning fire into our house in the second fireplace. My boyfriend intends to fit it himself but I am going to get a HETAS installer in to do the job (or at least finish it off) and make sure that it's safe and we don't die.
However, I want to keep the cost down by fitting the hearth and increasing the opening in the chimney breast and replacing the lintel ourselves.

Two issues-

1) The constructional hearth is damaged a bit with a loose layer on the top. On the advice of my builder (who is now unavailable for advice) we are going to remove the top layer that's beenchipped away and apply a new layer of mortar (?) to make it level with the floorboards.

He recommended a product that we could paint on the hearth before applying the new layer of mortar to make itdamp proof- any ideas what it might have been? and does that sound right?

2) When the constructional hearth is sorted, how do we fit the granite hearth on top? It is split in two halves (solid fuel) and it's kind of 'hollow' behind the sides on show (I hope you know what I mean, can't think how to describe it).

Any advice would be much appeciated.

 

[JerryM]

1) with old mortar chipped away would suggest fitting a piece of DPM (damp proof membrane) before covering with the mortar. only trick is to use sand or mortar to bed the DPM so that it doesn’t get pierced.

2) i use plaster board adhesive to seat and level granite hearths. put at least 4 biggish mounds on the mortar (floor) and lower the hearth onto them. the mounds need to be higher enough to contact the top surface of the hearth as it is lowered into position. try to avoid hitting the marble with anything as it's quite brittle and easily snapped. i've not use a split hearth before put would presume just but them together.

 

[norahclare]

Thanks for the advice. We'll be attempting it over the next couple of days so will let you know how it goes!