2 inch difference height between hearth and floor

[edyit]

Can you please tell me what kind of board?

this link should help you out a lot on figuring out what to get for R values

Sweep's Library - R Value of Hearth Materials

My wood stove requires floor protection with a certain R value. Where do I find this rating?

hearth.com

 

[tathspts]

can someone please advise why they have shown the floor protection starting at the bottom of hearth slab in picture 1 and from the top of hearth slab in picture 2? (picture attached)

Is this an error or this means something?

Thank you.

 

[rwhite]

can someone please advise why they have shown the floor protection starting at the bottom of hearth slab in picture 1 and from the top of hearth slab in picture 2? (picture attached)

Is this an error or this means something?

Thank you.

The easy answer is that it shows a level floor vs a raised floor. If the insert and hearth is less than 5" from floor level you need "B" to be 23" with an r value of 1 or higher. If it sits 5" or more higher than the floor you need "B" to be 16" of non combustible materials. That's why I mentioned how intrusive it would be. If you have 5" of stove outside the masonry wall then 23+5 gets you 28" of hearth. If its raised you will only have 21". Either can be easily done but it costs money. I would guess you'd be 2-300 in a DIY project to build it either way. May research other stoves that have lesser requirements. It could be a wash just to but a different stove.

 

[tathspts]

I seriously do not get the logic behind it. What difference the hearth level makes from the floor?

Say someone's hearth is 4 inch from the floor instead of 5. He now needs to extend it out to 23 inches? Stove itself has to be 3 inch out (look at value C). That mean a total of 26 inches from the wall. That will look ridiculous.

The easy answer is that it shows a level floor vs a raised floor. If the insert and hearth is less than 5" from floor level you need "B" to be 23" with an r value of 1 or higher. If it sits 5" or more higher than the floor you need "B" to be 16" of non combustible materials.

 

[rwhite]

I seriously do not get the logic behind it. What difference the hearth level makes from the floor?

Say someone's hearth is 4 inch from the floor instead of 5. He now needs to extend it out to 23 inches? Stove itself has to be 3 inch out (look at value C). That mean a total of 26 inches from the wall. That will look ridiculous.

That's how I read it. If you dont want a raised hearth the solution is to remove all the tile. Cut into the wood floor to accommodate another 8" of tile. Then build it back up with correct r value. It would probably end up 1/2" or so above floor level. Do you have access to the purlins under the floor?

 

[rwhite]

I'm no engineer so take this for what its worth. If you can determine what is used for under laymentand how thick it is. You can remove the tile and run stringers between and slightly lower than the joists so that the new underlayment is level with the top of the joists rather than on top of them. That may gain you another 3/4" . I know that some of the clearances seem overkill but once you get a fire going you will realize why. I had a very similar Osburn insert and the way it directed heat was such that directly in front of the stove stayed cool. 16" out on the hearth got very warm.

 

[rwhite]

Here is the only old pic I can find of my insert. As I recall it was 3/4" plywood, 2 layers of micore then hardiboard. By the time I tiled it was around 2.5". It was free floating. There was around 16" of tile underneath it which transitioned into hardwood floors. Almost the exact same as yours.

 

[EbS-P]

Are you getting the 2020 model. I am seeing some differences. Between what you posted and he 2020 manual I found.

 

[tathspts]

where did you find this manual? Can you please link me?

This is what I am looking at, https://sbiweb.blob.core.windows.net/media/2608/45931a_25-01-2019.pdf

this is directly from SBI website and is mentioned on their product page for drolet 1800-i. It does say EPA 2020.

Are you getting the 2020 model. I am seeing some differences. Between what you posted and he 2020 manual I found.

 

[EbS-P]

From the Costco website.

https://a.sellpoint.net/a/Escape+1800-I+owner%27s+manual.pdf?spworld_assetname=zGm9J31G.pdf&spworld_download=1&spworld_filename=Escape%201800-I%20owner%27s%20manual.pdf

where did you find this manual? Can you please link me?

This is what I am looking at, https://sbiweb.blob.core.windows.net/media/2608/45931a_25-01-2019.pdf

this is directly from SBI website and is mentioned on their product page for drolet 1800-i. It does say EPA 2020.

 

[EbS-P]

where did you find this manual? Can you please link me?

This is what I am looking at, https://sbiweb.blob.core.windows.net/media/2608/45931a_25-01-2019.pdf

this is directly from SBI website and is mentioned on their product page for drolet 1800-i. It does say EPA 2020.

I’d go with you sbi link. It looks like the newer one.

 

[tathspts]

yeah.

I’d go with you sbi link. It looks like the newer one.

 

[Stonehousekennels]

I had to build up my hearth for my insert. It just had the small red tiles like yours. I also wanted to make it wider and longer. I ordered a custom cut blue stone slab. I laid it on bed of mortar and it turned out awesome.

 

[tathspts]

I have decided to cut back the floor and make a 26 inche out hearth and keep everything at the floor level.

Decided to use a micore 300 underneath a marble of granite slab. Meeting the R value, dimensiona for hearth and keep everything including hearth at the same floor level to avoid any intrusion.

The way I see it I would need a 6 x 2.2 feet marble slab.

Next steps now are to figure out how to cut the floor just right so it is clean and straight cut, make sure I am not cutting the plywood underneath and make sure I am not chipping any corners of the floor that will stay while I am taking out the cut floor. Lastly where to get a piece of marble that size.

Any input are welcome.

 

[bholler]

I'm no engineer so take this for what its worth. If you can determine what is used for under laymentand how thick it is. You can remove the tile and run stringers between and slightly lower than the joists so that the new underlayment is level with the top of the joists rather than on top of them. That may gain you another 3/4" . I know that some of the clearances seem overkill but once you get a fire going you will realize why. I had a very similar Osburn insert and the way it directed heat was such that directly in front of the stove stayed cool. 16" out on the hearth got very warm.

That would not meet code at all.

 

[rwhite]

That would not meet code at all.

What would be the issue? I can't see where you would lose any structural integrity if for instance there were 2x10 joists and you sistered 2x8 along them that was 3/4" low. You could then box the sisters in to create additional strength.

 

[bholler]

What would be the issue? I can't see where you would lose any structural integrity if for instance there were 2x10 joists and you sistered 2x8 along them that was 3/4" low. You could then box the sisters in to create additional strength.

A hearth extension in front of an open fireplace has to be a self supporting concrete slab with no combustible materials touching the bottom of the slab

 

[rwhite]

A hearth extension in front of an open fireplace has to be a self supporting concrete slab with no combustible materials touching the bottom of the slab

So you cant have underlayment followed by micore or hardi board then tiled?

 

[bholler]

So you cant have underlayment followed by micore or hardi board then tiled?

Not for a permanent hearth extension in front of a fireplace no. Would it be safe as long as you met 4 requirements? Absolutely.

Would most inspectors catch it? Probably not.

But it doesn't meet the code requirements.

 

[rwhite]

Not for a permanent hearth extension in front of a fireplace no. Would it be safe as long as you met 4 requirements? Absolutely.

Would most inspectors catch it? Probably not.

But it doesn't meet the code requirements.

Had no idea. Thanks. So how are 2nd floor hearths constructed? Or what/how do you supports the concrete?

 

[bholler]

Had no idea. Thanks. So how are 2nd floor hearths constructed? Or what/how do you supports the concrete?

It should be a self supporting slab poured along with the main hearth. With either noncombustible forms or wood forms that are removed

 

[rwhite]

It should be a self supporting slab poured along with the main hearth. With either noncombustible forms or wood forms that are removed

Thanks bholler. I did find this reference.

Hearths and Hearth Extensions

www.nachi.org

So, another question. Once you convert an open fireplace to an insert does the open fireplace code apply or does the the requirements for the appliance apply?

 

[bholler]

Thanks bholler. I did find this reference.

Hearths and Hearth Extensions

www.nachi.org

So, another question. Once you convert an open fireplace to an insert does the open fireplace code apply or does the the requirements for the appliance apply?

If it is permenatly attached to an open fireplace it needs to meet code for that. Insert manufacturers generally required a compliant fireplace for installation. If you do a nonpermenant extension it only needs to meet insert requirements

 

[tathspts]

Bholler,
Will what I proposed up meet the code?

Had no idea building hearth extension would be so much trouble.

I am going to be first to admit, I drove in this fireplace game with head on without thinking it through.

Oh well let's see how it goes. I will keep you all posted. Thanks a lot for all the inputs, really appreciated.

 

[begreen]

Bholler,
Will what I proposed up meet the code?

Had no idea building hearth extension would be so much trouble.

I am going to be first to admit, I drove in this fireplace game with head on without thinking it through.

Oh well let's see how it goes. I will keep you all posted. Thanks a lot for all the inputs, really appreciated.

This is why I proposed considering a hearth extension board in post #23. If what you propose is not permanently attached to the existing hearth, then it would be ok.