How to raise fireplace floor?

[BPTom]

Hi, I will be installing a Harman 52i into existing fireplace (see picture), need help on how to raise fireplace inside floor:

There is a 7/8 inch difference between fireplace inside floor and the front (marble) hearth; how to raise the fireplace floor by just 7/8 inch and also to be able to mount the 52i frame on the new floor? I was thinking using two pieces of cement backer boards to reach 7/8 inch, would that be Ok? From the manual, there is no R value needed on the floor, i guess just need something the metal frame can be mounted on and stable.

Thanks so much. Have been reading and learning a lot from here.

 

[Irish916]

I'm curious on your solution here as well. Do you need a zero clearance box with this insert? I had an installer out to assess my pre-fab fireplace for this insert. He basically said they would control the elevation of the box by doing just what you suggested. Love to hear how this worked for you.

 

[kennyp2339]

Self leveling cement

 

[Big papa]

I think the accentra has leveling bolts so check before u do a bunch of work and don't have to

 

[hockeypuck]

Self leveling cement is probably overkill. Get the real cement board not the Styrofoam filled crap and call it good. I was going to tell you to cover the hearth with granite, but then I realized that you have a nice marble one. When I looked at your picture from my phone, it looked like concrete.

 

[BPTom]

Don't think I would need a ZC box; will let everyone know what I end up with.

 

[BPTom]

Self leveling cement

Thanks. This definitely could be better than multiple layers of cement boards I thought I might use.

 

[BPTom]

I think the accentra has leveling bolts so check before u do a bunch of work and don't have to

That would be great! Nothing in the manual mentions the leveling bolts. Thanks.

 

[BPTom]

Self leveling cement is probably overkill. Get the real cement board not the Styrofoam filled crap and call it good. Comes the hearth with some thin granite tile...

Is James Hardi backer board real cement board? Don't understand "comes the hearth with some thin title"? you mean cement board+cement+title together? Thanks.

 

[Big papa]

Yeah the manual is biased to having a tech install rather than u so something's aren't mentioned. check with ur dealer before u go out of ur way building up that floor

 

[Big papa]

I found a thread says accentra has 4 leveling bolts and they also can b shimmed under if needed

 

[BPTom]

Yeah the manual is biased to having a tech install rather than u so something's aren't mentioned. check with ur dealer before u go out of ur way building up that floor

Thank you! I think the leveling bolt will be the solution. My bad - didn't read the manual carefully, it does mention "4 leveling bolts .. in the bottom pan of the mounting frame". I would probably still put down a 1/2 inch JH backer board, then use the bolt for leveling.

 

[BPTom]

I'm curious on your solution here as well. Do you need a zero clearance box with this insert? I had an installer out to assess my pre-fab fireplace for this insert. He basically said they would control the elevation of the box by doing just what you suggested. Love to hear how this worked for you.

From Big papa's post, and the manual there are 4 leveling bolts can be used, so my solution would be 1/2 JH backer board with the bolts for leveling.

 

[Big papa]

Sounds like ur on the right track let me know how it goes and send pics when it's done please

 

[BPTom]

Sounds like ur on the right track let me know how it goes and send pics when it's done please

Will do, thanks for the help.

 

[John Fortier]

If you will be pulling the stove out you will destroy the backer board over time. If you are raising it aprox. 1/2" you would be better off with an inexpensive quarry tile and modified thinset to bed them. The floor will have to be cleaned first.

 

[Big papa]

The backer board should b under the rails that the stove slides on so shouldn't damage backer board and I'm a simple guy why put anything down on the floor shim the frame with some pieces of steel secure it and forget it