It looks like my only option from local home improvement stores is durock next gen 1/2", or hardiebacker. I picked up the next gen, but read it's not made for hearth construction, but is okay for a wall shield. Is this true?
Rear clearance for hearth with cement board?
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Durock NexGen is cement and pumice. I can't see anything there that would not work for hearth or wall shielding. Hardibacker board has cellulose in it. That would not be my first choice for backer board though some have used it without issue.
So NFPA states:
1⁄2-in. (13-mm) thick noncombustible
insulation board with ventilated air space. Minimum clearance as wall protector 6". Maximum allowable reduction in clearance 66%. So could I go 6" clearance in the rear or stick with the 12"? Thanks.
1⁄2-in. (13-mm) thick noncombustible
insulation board with ventilated air space. Minimum clearance as wall protector 6". Maximum allowable reduction in clearance 66%. So could I go 6" clearance in the rear or stick with the 12"? Thanks.
Grisu
Minister of Fire
12". That's the minimum distance allowed by NFPA guidelines for an unlisted stove. If you want to get closer than 12" you need to get a different stove that has been tested with less rear clearance.
From which version of the NFPA are you citing?
From which version of the NFPA are you citing?
NFPA 211. So for an unlisted stove, does 18" front and sides with 12" in the rear sound okay. I've got my durock and plan on building the pad and shield tomorrow.
Grisu
Minister of Fire
Yes, that sounds ok. 12" in the back is ok with a ventilated heat shield. With 18" in the front and sides you mean the size of the hearth or is that an alcove?
I was asking for the NFPA version as that citation was not in the 2003 and 2006 editions I have. Have you been looking at the 2013 version?
I was asking for the NFPA version as that citation was not in the 2003 and 2006 editions I have. Have you been looking at the 2013 version?
Grisu
Minister of Fire
I could not find this one:
But I think you were looking at the wrong section. The table on page 27 is for connectors. You need to look on page 38, paragraph 12.6 for solid fuel-burning appliances. Floor protection is in figure 12.6.2.1(b). Minimum clearances in table 12.6.2.1.
But I think you were looking at the wrong section. The table on page 27 is for connectors. You need to look on page 38, paragraph 12.6 for solid fuel-burning appliances. Floor protection is in figure 12.6.2.1(b). Minimum clearances in table 12.6.2.1.
I had another question. When creating my shield with 3" wide strips of durock doubled up as spacers, how many should I space between my 60" wide shield? Does it need to be entirely empty space between the two strips of durock on each end, or can I put a few more vertical strips to increase the strength of the shield?
Ceramic insulators are best. (for fencing or available in kit form) If you prop up a piece of cement board near a heat source you will find it gets very hot on the back as well. This is because it transmits heat very well. Its resistance to flow is very low. Also don't put any in the center line of stove. You set the heat shield on bricks, spaced for air circulation under it, (air intake) so the spacers do not support weight, they only hold it from the wall. Simply run a screw in to hit studs.
https://www.hearth.com/econtent/index.php/articles/stove_wall_clear
https://www.hearth.com/econtent/index.php/articles/stove_wall_clear
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Grisu
Minister of Fire
If you look closely at NFPA 211 you will see that the spacers should not be directly behind the stove but off to the side. The same should be true when you use several layers of cementboard. I second Coaly's suggestion of putting some bricks or other support under the wall shield that the spacers do not need to carry the full weight then you won't need to worry about having them only on the side.
Thanks for your replies! I was wondering about supporting the load of the wall shield. Instead of bricks supporting the bottom of the shield, what about using the entire sheet of durock, and cutting 1" air gaps along the bottom? Leaving maybe four 3" wide "footings" of the durock shield to sit atop the pad?
Also, where is the best place to buy ceramic spacers? Do local places like home Depot or lowes sell them? Thanks again!
Also, where is the best place to buy ceramic spacers? Do local places like home Depot or lowes sell them? Thanks again!
Yes that should work. Making a 1" thick spacer out of two 3" x 36" furring strips snapped off the Durock sheet is fine. Maybe make the bottom air slots a little more generous at the base, like 1.5-2" high.
Thank you. Also, in determining my shield height, is it correct to assume since my stove requires 36" distance from unprotected wall, the height of my shield must be 36" from the rear top height of my stove?
12" rear distance to the shield, 36" unprotected requirement = 34" on top of my stove height using a^2+b^2=c^2.
27" stove height, means 61" shield height? A bit tall for my liking, but I understand if that's my only option.
12" rear distance to the shield, 36" unprotected requirement = 34" on top of my stove height using a^2+b^2=c^2.
27" stove height, means 61" shield height? A bit tall for my liking, but I understand if that's my only option.
6" above the stove top should suffice unless single wall stove pipe is used. That has an 18" clearance requirement.
PS: The stove manual is located here:
https://www.hearth.com/images/uploads/Earthstove100_manual.PDF
PS: The stove manual is located here:
https://www.hearth.com/images/uploads/Earthstove100_manual.PDF
I've decided to go with the Englander Madison stove. The manual states it only requires ember and spark protection only. So I'm confirming I don't need to bother with a ventilated shield anymore, and a sheet or two of durock flush against the drywall is fine. Also, the manual states double wall chimney distance from combustibles is "N/A" does this means there is no distance requirement, and my double wall chimney can be 7" from the wall?
Thanks.
Thanks.
Grisu
Minister of Fire
I was wondering about that one myself. This post and the following may help: https://www.hearth.com/talk/threads/madison-in-my-burn-trailer.128150/page-2#post-1742182 but it would probably be best to contact @stoveguy2esw directly.
That's for the hearth underneath.
Even drywall by itself is fine but you will need to have the minimum distance between wall and stove as listed in the table in the manual. The durock won't reduce your clearances but you can still do it for looks (e. g. with tile on top) and added peace of mind.
I have taken N/A to mean "not applicable". That is the minimum stove clearance requirements do not change in correlation with the clearances of the double-wall connector pipe. There is no gain in clearance reduction due to the double-wall pipe.
Note that it does not hurt at all to exceed minimums
stoveguy2esw
Minister of Fire
On ES Stove install I'm going with galvanized corrugated roofing with recycled garage door track fastened to the wall for my one inch space all the way the chimney.
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