raised hearth dilemma for Enviro M55 pellet insert

Hello all,
We just got a Enviro M55 pellet stove insert.

I have a little issue I'm facing with respect to the the hearth pad (extension) and my fire place.
The base of my fire place is about a whopping 8 inches raised off the floor.
Based on what I'm reading here, it appears this is not a common situation.
When looking for buying a hearth pad we were shocked to find out that it costs upwards of $400

Looking at the manual it doesn't specify any R value or anything like that for the hearth.
I have no idea how hot it gets at the base of the stove when running it at high say in the middle of January when it's really cold.

Based on some research online, one idea seems to be to:
build a basic frame out of a 2x6 or a 2x8 (this will give some height)
lay some plywood on top, and screw on a concrete backing board.
And lay some tiles on top.

I've never done any tile work before.
I'm also concerned that the plywood and the 2x4 are not exactly non-combustible.
Not also sure what a safe tile that will meet the proper safety codes will be.

I was initially hoping to just lay some paving stones but they seem to be extremely heavy and I'm worried about putting so much weight on the floor, on top of which the already heavy stove will rest on. It takes a quite a few stones to cover the area given the stove dimensions and the 6 inch clearance as suggested by the manual. It amounts to about 48"x20" for a height of 8". Controlling the height to get it to flush with the base of the fireplace is another issue.

I'm not exactly a handy person, but I need to solve this problem soon as I've scheduled the install in a few weeks and this is really stressing me out.
I don't want to screw something up either in terms of safey while trying to save money.

Thank you for any advice you can provide.

BTW, there does exist a hearth on the floor currently that is flush against the floor level.
Whatever solution I come up with will go on top of this to provide both the raised support and also serve as the hearth for the front of the M55.

Thank you hwdemers.

Does the ember protection minimum mean the ceramic tile+cement board on plywood safe enough?
Not sure how hot the M55 gets at the base where the contact is made on the tile (I assume it does and it's not free standing).
Would be great if some M55 insert owners commented on that.

Yes bluestone is very much an option. In this case I would assume I'd put the bluestone on top of the cement board (over plywood over 2x6 frame)?

I will try to get some pictures and post when I get home.

Thanks again - I appreciate the help.

Thank you Aquion - your reply got posted while I was composing mine.
That's great to hear that the exterior doesn't get too warm.
I was just concerned especially when looking at the manual where they show the base of the stove insert (the part that's outside the fireplace) resting on quite a bit of masonry and it specified a 6" clearance in the front ON TOP of that.

Any idea how much weight the stove (the part that's outside the fireplace) will put on the hearth - about 100 or so pounds? I assume the bulk of it is in the back that's INSIDE the fireplace?

Thanks again.

Thanks, Papelletman.

Would you recommend a specific kind or thickness of tile to use, porcelain vs ceramic, outdoor vs indoor?
Or am I overthinking this?

hwdemers said:

I measured the tem at the ash pan today on high for 30min. Got a 82. I've never seen it even get hot to the touch. The heat exchanger is a the top sucking all the heat out of it not radiating it out into the room. That being said I looked in the Manuals and it must be steel framed with 1/4 backer board plus tile or masonry. Tot a l over kill but the rules are the rules

Click to expand...

Wow, that's very helpful of you, hwdemers. Thanks so much.
Could you please point me to which manual you got this info from and perhaps the page numbers.
I've been poring over the "technical manual" and the "owners manual" - no mention of anything of this sort unfortunately.
I presume you also own an M55 insert.
If you could please point me to a pdf of the section you're referring to I'd really appreciate it.
Thanks so much again.

Also hwdemers, this being only still early October and not the peak of winter yet, is it possible your reading might be higher than 82 say in the cold of Jan or Feb?
Perhaps the stove may run at a higher setting than now and run hotter?
Forgive me I'm such a newbie at this but just wondering out aloud.

skinanbones said:

Your situation is a bit of a grey area. But because your are building a hearth that goes under the unit, i would use the information that Enviro supplies for the Insert model to allow it to be installed as a zero clearance unit. Take a look at page 22 of your manual where it has a diagram of how they want the hearth built, with steel studs, cement board, and than tile and grout.
Here's a link to current manual on Enviro's site. http://enviro.com/custom_content/docs/manuals/C-13794 Instruction M55C-FPI Domestic Owners Manual.pdf

Click to expand...

Thanks skinanbones - that makes it very clear!
You're right in my case the stove is pretty much sitting on the pad I'd put down.
Probably all of the hot parts I'd imagine.
You've made me think now (and a lot nervous).

Papelletman said:

I used some left over ceramic tile from when I did my kitchen with a boder of a darker color, they are about 3/8" thick.

View attachment 138444 View attachment 138445

Click to expand...

Wow that's really nicely done!! Looks great!