NEED ADVICE ON LAYING BRICK FOR HEARTH PAD

[plenzlerjm]

Hey, the saga continues...I'm nearing completion of my hearth pad.

Does anyone know what the best way to set 1/2" thin brick on 1/2" Durock?

I hear that you can't just use any old grout since heat is a factor...ie don't want weird fumes from polymers heating up in certain grouts.

Also, I used a few screws to attach the Micore to the plywood around the periphery. Is there any concern here about heat transfer from the screw to the plywood?

Any advice on "how to" is much appreciated


My hearth pad is constructed thus:


1/2" thin brick
1/2" Durock NextGen
30 gauge galvanized sheet metal
5/8" Micore 300
1/2" Plywood
Hardwood Floor
Wood Subfloor

 

[amkazen]

Hi,

Let me describe the hearth I built and see if it helps you move further along.

Original floor:
wood subfloor
2" of gypcrete
soundproofing for 1/4" thick click together laminate floor

Hearth:
removed laminate floor
removed soundproofing
created a hearth base using steel studs: did not screw studs to gypcrete..just set them down, to avoid the chance of screwing into radiant floor piping..so, you could consider it a "floating" hearth
screwed 1/2" cement board/equivalent to steel studs, which tied studs together
screwed 1/2" cement board/equivalent 6" on-center to 1st cement board
laid 2" thick cultured stone slabs in thinset mortar on top of 2nd cement board
grouted stone slabs on top of 2nd sheet of cement board/equivalent
nothing special about the grout or mortar in regards to heat resistance
hearth is about 2" or so above remaining laminate floor

Personally, I do not think you have anything to worry about in regards to the mortar, grout, or screws. My hearth does not get hot at all as there is plenty of air floor under and around the stove.

I got the idea for my hearth construction from reading the cement board/equivalent ( I forget what I used..Wonderboard? Durarock?) specs for heat purposes, the stove manufacturer's website for required clearances, and the local code book for fireplaces & wood stoves to see if there was anything in them of interest for this project.

We have never had any issues, and my "floating" hearth looks great and will take 800 people to pick up & move if needed! LOL

I hope this gets you moving along instead of waiting for an answer...as I am having to do on my door gasket issue..... But, it is not like I do not have a bunch of other projects to keep me busy the next few days.

 

[Hogwildz]

For what you are doing, good ol mortar should do.
Not sure how the galv screws will affect the Durok if at all. I used screws made for fastening durok. Prolly not an issue as it won't be seeing any moisture.

 

[plenzlerjm]

Hi,

Let me describe the hearth I built and see if it helps you move further along.

Original floor:
wood subfloor
2" of gypcrete
soundproofing for 1/4" thick click together laminate floor

Hearth:
removed laminate floor
removed soundproofing
created a hearth base using steel studs: did not screw studs to gypcrete..just set them down, to avoid the chance of screwing into radiant floor piping..so, you could consider it a "floating" hearth
screwed 1/2" cement board/equivalent to steel studs, which tied studs together
screwed 1/2" cement board/equivalent 6" on-center to 1st cement board
laid 2" thick cultured stone slabs in thinset mortar on top of 2nd cement board
grouted sone slabs on top of 2nd sheet of cement board/equivalent
nothing special about the grout or mortar in regards to heat resistance
hearth is about 2" or so above remaining laminate floor

Personally, I do not think you have anything to worry about in regards to the mortar, grout, or screws. My hearth does not get hot at all as there is plenty of air floor under and around the stove.

I got the idea for my hearth construction from reading the cement board/equivalent ( I forget what I used..Wonderboard? Durarock?) specs for heat purposes, the stove manufacturer's website for required clearances, and the local code book for fireplaces & wood stoves to see if there was anything in them of interest for this project.

We have never had any issues, and my "floating" hearth looks great and will take 800 people to pick up & move if needed! LOL

I hope this gets you moving along instead of waiting for an answer...as I am having to do on my door gasket issue..... But, it is not like I do not have a bunch of other projects to keep me busy the next few days.

Perfect! Very helpful. Many thanks!

 

[plenzlerjm]

For what you are doing, good ol mortar should do.
Not sure how the galv screws will affect the Durok if at all. I used screws made for fastening durok. Prolly not an issue as it won't be seeing any moisture.

Thanks!

 

[CTguy9230]

if the screws that are holding your durarock to the plywood are that hot...


you have a much bigger problem then your woodstove

 

[begreen]

I think Joe gets that pretty well. Not an issue. His hearth sounds like it is going to be really skookum and far above the requirements for his Encore.

 

[Gooserider]

The hearth proposed sounds pretty good to me, and I doubt that the screws will be a problem, especially given the sheet metal which will tend to dissipate any heat the screws pick up.

For what it's worth, a few years ago I posted an article on hearth construction in the Wiki section, based on when I built a hearth extension to make things legal for the Encore that I was installing in place of a side-door only stove. I forget offhand just what I used for mortar and grout, but there were some specific formulas recommended by one of the resources I used as to what would be most heat resistant and so forth... I used slates on my extension, but I would expect that the same stuff would work with thin bricks...

Gooserider