Building a Hearth

My hearth pad is made of Indian Silver Slate and it does chip/scratch easy. Here is a site that gives some good info on care! With this in mind I still went with slate! Love the feel/looks!

http://www.baneclene.com/articles/slate.html

Just ooc - what stove did you select?

I had a new floor put in my living room which is where my insert is.

We replaced the tile that made the hearth with different tile.
Huge mistake. After three years every tile is cracked.


Getting a new fireplace later this month and getting a new hearth built s well. Only heav duty stone this time.

This site gives the info on what you would need for enough heat resistance http://www.hearthclassics.com/thermal_protection_thermashield.php

The Republic 1750 only needs a non-combustible surface, 0.018" thick (26 gauge).

leftyscott said:

I had a new floor put in my living room which is where my insert is.

We replaced the tile that made the hearth with different tile.
Huge mistake. After three years every tile is cracked.


Getting a new fireplace later this month and getting a new hearth built s well. Only heav duty stone this time.

Click to expand...

It is likely that the tile used wasn't to blame as much as the installation. If not set properly they will crack, even "heavy duty"tile.

I concur with the above comments on tile. Both of our hearths are tiled and there has been no cracking whatsoever even under the substantial weight of soapstone stoves. The only cracking I've yet encountered was the grout seam along the chimney on the studio's hearth. And since I am rank amateur with respect to tiling and grouting I suspect the fault lies in my own failing, not the products used.

Our two hearths are both raised and well framed with 2x10s, plywood, and topped with cement board. We paid particular attention to beefing up the area that would support the 550 lb. stoves.

I believe Micore 300 has a very high R-value. I priced out a 4'x8' board 1/2"thick for $31. I will double it up as two 4'x4'. Then some wonderboard and tile. Durock has introduced styrofoam so it has lost some rvalue.

My slate hearth has held up one season so far and I see many more in it's future.

https://www.hearth.com/econtent/index.php/forums/viewthread/19556/

i sell Avalon stoves, my undestanding is 3/8" non combustible material.

here are some examples of r values for various materials
Gypsum or plaster board1 1/2″ r0.45
Wallboard, Wonderboard, or
Durock1
1/2″r 0.20
Ceramic board (Fiberfrax or Micor)1 1/2″ r1.10
Nominal solid clay brick1 1″ r0.20
Ceramic wall or floor tile1 1/4″r 0.01
Mineral wool insulation2 1″r 3.12
Cement mortar2 1″r 0.20
Horizontal still air2 * 1/8″ r0.92

Would suggest you leave a space about 1/4" to 3/8" between the slate and the back wall. Fill this space with acrylic latex or other unsanded paintable caulk which matches or contrasts color with the new grout, the tile or the back wall. As Bobbin said, grout in this space will probably crack because of slight movements or expansion/contraction between the wall and the hearth. "Distance to combustibles" should not be a concern with the caulk because this section of the hearth and wall should already be farther than the required minimum setback. Silicone caulk will also work in this application but is not paintable.

Good luck with your project.

John_M

We used natural multicolor slate 12 x 12 x 3/4" thick approx. and sealed it with a stone/tile sealer with low gloss look. It has held up for two years with no cracks and I have dropped many logs on it. I framed the hearth with 2x6 and covered it with 2 layers of 1/2"cement board and high temp rated mortar. Slate was tough to cut(wet saw only) and much heavier so doing the wall with it was more challenging to keep it from sliding. its very durable.