Blue Stone

[USMC80]

can anyone tell me what the r-value for 1" thick bluestone is?

 

[USMC80]

tore out old hearth and looking to bring up my hearth to code for a hampton hi300. I have two inches to bring it up even with the firebrick. Was wondering if an inch of mud and some 1" bluestone would work? Heres a pic of the old one torn out

 

[begreen]

I don't know, but would expect it to be pretty low. Stone conducts heat fairly well, especially after hours of exposure. My guess would be below R=0.1 .

(broken link removed to http://www.chimneysweeponline.com/horvalue.htm)

 

[ScotO]

I agree with BG. I'd look into cutting some more of the wood floor out and making the hearth bigger. What is underneath your wood floor? Or, better yet, do you have any room to raise the stove up in the existing fireplace, so as to possibly build a frame out of steel 2x4 studs and build a raised hearth? That would give you airspace under the hearth, which I think you could vent to the back of the fireplace if done correctly....put a layer of durock down on the studs and put stone or tile on top of that, it'd look really nice to boot!

Just pitching some idears your way...

 

[USMC80]

im cutting 7 more inches out in front. I took out the mortar and marble and its still some kind of cement/concrete on bottom as you can see in the pic, then the subfloor underneath that. No room to raise the hearth at all

 

[Don2222]

can anyone tell me what the r-value for 1" thick bluestone is?

Check out this link for R values for a wide variety of materials
http://www.coloradoenergy.org/procorner/stuff/r-values.htm

Probably similar to concrete block. R 0.8 ! ! !

 

[daryl]

That looks like a full masonry fireplace. Most masonry fireplaces do not have floor joists under the hearth they are most often formed and poured in place. If that is the case you already have a non combustible hearth.But I would check first not all masons did it right.

 

[USMC80]

That looks like a full masonry fireplace. Most masonry fireplaces do not have floor joists under the hearth they are most often formed and poured in place. If that is the case you already have a non combustible hearth.But I would check first not all masons did it right.

yes the joists stop on the sides of the hearth but the concrete has wooden planks under neath it (looking up from the basement)

 

[ScotO]

im cutting 7 more inches out in front. I took out the mortar and marble and its still some kind of cement/concrete on bottom as you can see in the pic, then the subfloor underneath that. No room to raise the hearth at all

How thick is that cement substrate that's under the original hearth? What is the requirements for the Hampton's front clearances and under the stove? I'm betting that if the cement substrate is thick enough, you just may be OK with the bluestone...

 

[USMC80]

not sure how to tell how thick it is? Hearth thickness of .5 for hampton and 18 inches from the glass

 

[daryl]

Then two layers of Micore and 1" blue stone should be enough.

 

[ScotO]

I agree with daryl.......
Worst case scenario, if you are within code for the install on the frontal clearances and you still feel like the wood floor is getting too warm, you can always put a hearth rug down in front of the hearth.....

I'm anxious to see your project progress. You do realize (now that you have us "on the hook" here) that you are obligated (by the rules of the members and, 'unofficially', the forum code itself) to provide updates and TONS of pictures as the project progresses, so that us others can live vicariously through you and enjoy the install as well, right?

 

[USMC80]

thanks for the help guys! I'm excited as well, my brother will help me get started tomorrow. Don't think we will finish tomorrow because we have to cut out the front of the floor. I'll snap lots of pics and keep everybody updated.

My brother feels pretty confident that the mortar and bluestone will be fine, and I could always do what Scotty said. I am within code on all side and front clearances and was able to keep the mantle with this particular insert. We will be adding brick where the marble was on the sides and top

 

[USMC80]

ok got the top marble off, all ready for tomorrow

 

[lumbering on]

You've all got me worried now. My set-up looks almost identical to his, and I ripped out some ugly tiles and put in a piece of bluestone in the same place he is putting his.

What should I worry about?

 

[USMC80]

Sorry lol. I really think mine will be fine. Of course I will keep a close eye on it for the first weeks of burning

 

[Jags]

You've all got me worried now. My set-up looks almost identical to his, and I ripped out some ugly tiles and put in a piece of bluestone in the same place he is putting his.

What should I worry about?

Bluestone and tile will have roughly the same R value. Probably no need to worry if the tiled install was up to code.

 

[lumbering on]

Probably no need to worry if the tiled install was up to code.

That's a big if. House dates to 1907 and last remodeled in late 40's. Then abandoned for 3 years.

 

[begreen]

That's a big if. House dates to 1907 and last remodeled in late 40's. Then abandoned for 3 years.

It will depend on the replacement stove you get. Many new stoves just require ember protection. If that is the case, bluestone is fine.

 

[lumbering on]

It will depend on the replacement stove you get. Many new stoves just require ember protection. If that is the case, bluestone is fine.

What about my leyden? Is bluestone an issue with the Leyden?

 

[begreen]

The Leyden is ember protection only. Bluestone with grouted joints would be fine for that.

 

[USMC80]

Brother prepped, cut and did a dry layout of the blue stone yesterday. We were gonna set it but figured we would cut back the front and add another course of firebrick to the front of the firebox. He was worried about the heat cracking the blue stone in the front. So that set us back and will have to set it this weekend after the firebrick is set in

 

[USMC80]

forgot, also installed this bad boy. Moves A LOT of air

 

[USMC80]

back to work yesterday

 

[USMC80]

now just need to wash it, seal it, trim it and install the insert! Trying to get it scheduled for Thursday installation