Quick hearth question ...

[Crisnnik]

I'm new on here, and have been perusing the forums for a while while in the decision making process about installing a wood stove. Oil is too expensive now, and I want to help curb my consumption of it. I had settled on the Englander 30-NCL, but I just had a GREAT conversation with Mike at Englander, and I am now opting for the smaller 13-NCL. Should be enough to complement my heating situation in this 1800 ft2 house. My question is this; for the hearth, I plan on using metal studs to create a frame, then insulating inside it with fiberglass batt. Is this the same as what you use for walls, or is there another type I need? On top of this, I will put (2) 1/2" layers of Durock, then cover with tile. This should far exceed the R-value of 2 that is required. Any insight would be appreciated.

Thanks!

 

[Harley]

I think you would be OK without the bats, but if you are going to put them in, I would think most any unfaced insulation would do the job.

Here's a thread that DonCT starting showing his construction of a hearth similar to what you are planning:
https://www.hearth.com/econtent/index.php/forums/viewthread/1837/P0/

 

[Crisnnik]

Thanks for that thread - actually it kind of freaked me out!! That is exactly what I am doing. Removed a junk fireplace from the corner, tore down the wall, installed Class A chimney 25 feet up the chase (Excel pipe - heavy, but very nice), and my footprint is almost identical! I will make sure I get DUROCK )

 

[Crisnnik]

Another thought. I was going to do 1/2" Durock spaced an inch from the wall to gain closer tolerances. But if the smaller stove still fits nicely on the hearth with Durock and tile attached directly to the wall, can I skip the spacing? The manual says "combustible clearance is 13.5", so if I rock and tile the wall directly, and stay "at least" 13.5" from the surface of the original sheetrock wall, shouldn't I be OK?

Thanks again.

 

[nshif]

Yes you only need to be 13.5 from the combustable not the over layment of non combustables.

 

[stoveguy2esw]

thanks for the plug chris, told ya these guys would pull the right thread right up, great bunch in here , ive learned a lot from them myself

 

[Gooserider]

I'm new on here, and have been perusing the forums for a while while in the decision making process about installing a wood stove. Oil is too expensive now, and I want to help curb my consumption of it. I had settled on the Englander 30-NCL, but I just had a GREAT conversation with Mike at Englander, and I am now opting for the smaller 13-NCL. Should be enough to complement my heating situation in this 1800 ft2 house. My question is this; for the hearth, I plan on using metal studs to create a frame, then insulating inside it with fiberglass batt. Is this the same as what you use for walls, or is there another type I need? On top of this, I will put (2) 1/2" layers of Durock, then cover with tile. This should far exceed the R-value of 2 that is required. Any insight would be appreciated.

Thanks!

Welcome to the Hearth... I have to admit that I am not really comfortable with the 2 half inch sheets of Durock over studs - I've been having some conversations with the folks over at the John Bridge tile site (they do for tile what we do for wood stoves) and the experts over there are of the opinion that you don't get enough structural strength w/ a couple layers of Durock.

If you are going to do it that way, I would put the studs on much closer spacing than the standard 16" - possibly 8-10" centers? I would also make sure to put a layer of thinset between the Durock sheets in order to "glue" them together and make a laminated structure.

For the insulation, it may not be needed, but won't hurt to use it. I believe you can use normal house grade fiberglass without any paper facing - either peel it off or buy the non-faced stuff.

Gooserider

 

[Crisnnik]

Thanks alot Gooserider for the input. I actually had the same concern with the steel studs after feeling them today. I decided to get twice as many and pair them up to make a virtual hollow 2x4. They seem so much stronger. I was going to do 12" centers, with a few even closer directly under the stove area. As far as laminating them together, can I use the normal versabond thinset mortar to do that? I have plenty of it, and it sounds like a good idea.

So they way it is now, I have 2x4 metal studs on the plywood floor, I will have 2 inches of uncompressed, unfaced fiberglass bat inside that area. I will then lay 2 layers of 1/2" Durock on top, each layer only secured to the layer beneath it (staggered screws). Probably going to place mortar between Durock sheets now. I will also be sure to stagger the joints on the Durock sheets. Then another layer of mortar with my 1/4" ceramic tile on top. This should, from what I can find, more than cover my needed R-value of 2. On the wall, I am still unsure if I want to go direct to the sheetrock with the Durock, then tile, or if I want to mess with a ventilated airspace. I think (and will double, triple check) that the stove will fit comfortably within limits even if I don't space it.

This is the plan. Won't be actually doing it for a while, as I am off to the Caribbean in 2 days, but I willl tackle it upon my return to the cold. Any further insight is most appreciated.

 

[Gooserider]

Thanks alot Gooserider for the input. I actually had the same concern with the steel studs after feeling them today. I decided to get twice as many and pair them up to make a virtual hollow 2x4. They seem so much stronger. I was going to do 12" centers, with a few even closer directly under the stove area. As far as laminating them together, can I use the normal versabond thinset mortar to do that? I have plenty of it, and it sounds like a good idea. You will have plenty of R-value for certain - you'll get R-0.26 from each layer of Durock, plus R-0.97 an inch for dead air or R-3.33 per inch for the fiberglass bats, so you will have something between R-4 and R-12 on the hearth pad - MAJOR overkill...

So they way it is now, I have 2x4 metal studs on the plywood floor, I will have 2 inches of uncompressed, unfaced fiberglass bat inside that area. I will then lay 2 layers of 1/2" Durock on top, each layer only secured to the layer beneath it (staggered screws). Probably going to place mortar between Durock sheets now. I will also be sure to stagger the joints on the Durock sheets. Then another layer of mortar with my 1/4" ceramic tile on top. This should, from what I can find, more than cover my needed R-value of 2. On the wall, I am still unsure if I want to go direct to the sheetrock with the Durock, then tile, or if I want to mess with a ventilated airspace. I think (and will double, triple check) that the stove will fit comfortably within limits even if I don't space it.

This is the plan. Won't be actually doing it for a while, as I am off to the Caribbean in 2 days, but I willl tackle it upon my return to the cold. Any further insight is most appreciated.

Sounds like you should be doing well on the steel studs, that sounds like a good plan. You might also want to put some short peices on the same centers going crossways so you end up with a grid - it might be over kill, I don't know, but that way you will have no unsupported areas.

As to the thinset - Durock explicitly called out two ANSI standards that they wanted to have the thinset meet, 118.4 and/or 118.1 and their tech support guy said that basically translated to "Latex Modified" - IIRC, the Versabond is a premix tub stuff, and if so it doesn't meet the specs - the guy said none of the premix products were suitable. Flexbond was a brand he mentioned, and it meets both standards. I'm not positive, but I believe the reason is that the Latex Modified stuff is supposed to be better able to handle the thermal expansion / contraction cycles that are going to be associated with a hearth.

On the wall, if you meet clearances then it doesn't matter which you do, however one potential advantage of going with the space is that if you should ever decide to change to a different stove with higher clearance requirements, you will be that much ahead of the game if your walls are NFPA protective rated. Given that it would be no real extra work to include the spacers, I would consider it a good thing - future proofing is nice if it can be done w/ minimal extra cost and effort.

Gooserider

 

[Crisnnik]

The thinset I have is Versabond powder, and it says it DOES meet ANSI 118.4 and ANSI 118.11 without the need for additives. So I guess I'm good to go. This has been quite the learning experience for me - I am really enjoying it.

 

[Crisnnik]

OK - back from the cruise, and it was fantastic! SOoooo warm! Then returned to the cold. I had taken a couple of days off on the back end in order to get the project rolling, and I have made a lot of progress. I settled on the 2x4 steel studs, doubled up to create a "hollow 2x4" for strength. These were installed on 8" centers. I then put unfaced fiberglass batt in the spaces. On top of that I have 3 layers of 1/2" durock, all laminated with ANSI compliant mortar, with staggered seams. Each layer attaches with durock fasteners to only the layer below it.

On top of this I have the same mortar holding my PEI IV Porcelain tile. I do believe I have met my required R-value of 2.0. According to what I find, the insulating layer alone is R-6, if I can trust that ... For the wall, I have installed 1/2" Durock spaced from the sheetrock 1" with copper spacers. There ia also a 1" airgap at the bottom, and both spaces will be left open for air flow. I think this allows me a tighter clearance to the sheetrock, although I will still probably end up about 12 - 14" from the sheetrock at the corners.

Here are some pics. Any input would be appreciated.

 

[Harley]

Very nice work, Chris!

Just out of curiosity... that little "jog" out that the hearth takes on the left hand side of the picture..... what is that for? Is there a door there a little farther to the left that is not shown in the pic?

 

[MrGriz]

Looking great Chris! All that's missing is a big steel box filled with fire!

 

[Rhone]

Very nice work, Chris!

Just out of curiosity... that little "jog" out that the hearth takes on the left hand side of the picture..... what is that for? Is there a door there a little farther to the left that is not shown in the pic?

My guess some space for wood.

 

[Crisnnik]

Very nice work, Chris!

Just out of curiosity... that little "jog" out that the hearth takes on the left hand side of the picture..... what is that for? Is there a door there a little farther to the left that is not shown in the pic?

No door - I just had carpet missing there anyway (tearing out the old fireplace was messy, and did not go well on that side, so I decided to add a bit on that side to keep a couple of pieces of wood on, instead of carpeting the whole room!

 

[Gooserider]

Looks like a good job to me...

Gooserider

 

[Crisnnik]

Thanks guys - here's a pic of the cleaned and finished tile before I left yet again for Turkey Day. Happy Thanksgiving to you all.

 

[BrotherBart]

Thanks guys - here's a pic of the cleaned and finished tile before I left yet again for Turkey Day. Happy Thanksgiving to you all.

Now that is nice. That 13 is gonna be a happy camper in it's new home.

 

[Hogwildz]

That is nice man! When that wall is painted, it will be brochure quailty.
damn fine job! And ya got the ol man BB's approval.

 

[Gooserider]

Looks good to me, I would say it falls in the "done right" category.

Gooserider

 

[Crisnnik]

Well ... almost there! Waiting for the neighbors to come help move it and get it running. Hopefully tonight! One of my neighbors installs these for a living, so I will let him finish up the rest. Crossing my fingers.

 

[Crisnnik]

Quick question - the manual says the corner clearance "To Combustibles" is 13.5" with single wall, no heat shields. It is 8.5" with double wall with heat shields. I have not purchased the side heat shield kit, but I do have the Durock/porcelain tile backer with a 1" air gap between the Durock and the sheetrock wall. The stove currently sits at 10" from rear corner to tile, or 12" corner to the sheetrock. Will this be ok? I assume the 13.5" is with NO REAR WALL. So WITH a 1" gap tile wall, I am almost at, what I assume to be, the NO Wall protection distance. Just want to be sure ...

 

[Gooserider]

Quick question - the manual says the corner clearance "To Combustibles" is 13.5" with single wall, no heat shields. It is 8.5" with double wall with heat shields. I have not purchased the side heat shield kit, but I do have the Durock/porcelain tile backer with a 1" air gap between the Durock and the sheetrock wall. The stove currently sits at 10" from rear corner to tile, or 12" corner to the sheetrock. Will this be ok? I assume the 13.5" is with NO REAR WALL. So WITH a 1" gap tile wall, I am almost at, what I assume to be, the NO Wall protection distance. Just want to be sure ...

Are you sure there is nothing in the manual about just having a protective wall and no shields? IMHO this sounds to me like something that you ought to be OK with, but I can't say for sure. Hopefully it will be something that Mike and / or Corie can / will be able to answer... ("Not in the book" questions can be awkward for them since they aren't supposed to tell you anything that hasn't been tested and listed...)

Gooserider

 

[KWillets]

I was just looking at the same issue. Page 9 of the installation manual adds the following modification to the distance table (Illustration 1 is the clearance diagram and table), so apparently you can reduce to one-third of the listed clearance:

Please see Illustration 1 for clearances to walls. In some areas local codes may require thirty-six
inches (36”) from a combustible, therefore it is very important that you check with local officials. If
you need to place your unit closer to a combustible wall, some protection will be necessary. If an
approved wall board is used this will reduce your clearance by two thirds (2/3); however, a one inch
(1”) air space has to be between the board and the wall.

This is the user manual linked from homedepot.com's page for the stove.

http://www.homedepot.com/catalog/pdfImage/54033b32-b23a-4931-acb4-9e4247959f04.pdf

 

[Gooserider]

I was just looking at the same issue. Page 9 of the installation manual adds the following modification to the distance table (Illustration 1 is the clearance diagram and table), so apparently you can reduce to one-third of the listed clearance:

Please see Illustration 1 for clearances to walls. In some areas local codes may require thirty-six
inches (36”) from a combustible, therefore it is very important that you check with local officials. If
you need to place your unit closer to a combustible wall, some protection will be necessary. If an
approved wall board is used this will reduce your clearance by two thirds (2/3); however, a one inch
(1”) air space has to be between the board and the wall.

This is the user manual linked from homedepot.com's page for the stove.

http://www.homedepot.com/catalog/pdfImage/54033b32-b23a-4931-acb4-9e4247959f04.pdf

Well, one third of 36" is 12" so it looks like Crisnnik should be OK with his one inch clearance.

Gooserider