"ember only protection"

[trucha]

Hi guys,

I am looking to install a woodstove in my house which would include a new hearth area since there is none there now. I've seen several mentions of "ember only protection" needed and I don't know what this is but I can guess that it would just be a non-combustible material. The current floor is hardwood and I don't want to rip it up. So I am thinking of a piece of metal or glass laid over the wood would do the trick. Am I right?

Also, is there a way to see the R values required for floor protection for certain stoves? I found that the hearthstone catalog lists it but Jotul and morsi do not. After googling for hours yesterday trying to find that info I finally decided to watch a you tube video of stoves burning and I clicked on one from Jotul. There the guy from jotul described the stove and said it required ember only protection.

 

[begreen]

Hearth requirements vary with the stove, even within the same company. If the stove requires ember-protection-only then you would be ok with tempered glass or metal as a hearth pad as long as it meets the hearth pad size requirements.

 

[firefighterjake]

Hi guys,

I am looking to install a woodstove in my house which would include a new hearth area since there is none there now. I've seen several mentions of "ember only protection" needed and I don't know what this is but I can guess that it would just be a non-combustible material. The current floor is hardwood and I don't want to rip it up. So I am thinking of a piece of metal or glass laid over the wood would do the trick. Am I right? Yes . . . you are correct . . . if it states only ember protection is needed. That said, I feel much better with a bit of R value under my stove, but that's me being a worry wart since the manufacturer clearly states only ember protection is needed.

Also, is there a way to see the R values required for floor protection for certain stoves? I found that the hearthstone catalog lists it but Jotul and morsi do not. After googling for hours yesterday trying to find that info I finally decided to watch a you tube video of stoves burning and I clicked on one from Jotul. There the guy from jotul described the stove and said it required ember only protection. Can only speak to Jotul . . . many of their stoves only require ember protection . . . it seems that many manufacturers that require a certain R value will contain that information in the manual . . . which can often be found on line.

 

[farmboy05]

I've seen several mentions of "ember only protection" needed and I don't know what this is but I can guess that it would just be a non-combustible material. The current floor is hardwood and I don't want to rip it up. So I am thinking of a piece of metal or glass laid over the wood would do the trick. Am I right?

Yeup, same what as FFJake said. So any pre-built pad would work if you wanted to go that rout. One note on this though, if you decide to lay some tile yourself, some codes will require some kind of cement or fire board under the tile. This is to make sure there is ember protection incase you have some grout crack/break apart and an ember gets in there.

 

[trucha]

Thanks for the replies. I'd rather not lay down tile as that would require cutting and removing the old wood floor and I would like to leave that there. I saw a picture online just black metal the same color as the stove for a hearth pad as well as tempered glass and I thought it looked really cool. Maybe I will get the metal and put it on some sort of insulating material then.

 

[Heatsource]

i've always considered ember protection to be a min of 3/8" thick non combustible material.
maybe i'm wrong?

 

[trucha]

good question. What is the definition of "ember protection". Any non-combustible material? Only certain ones? Is there a thickness requirement?

 

[ccg36]

you are correct trucha, ember protection is any non-combustible material. Morso sells tempered glass hearth "pads" for their stoves, they look really slick.

 

[jeffesonm]

I installed a Jotul F55 and used a piece of 1/2" tempered glass for protection on top of my wood floor. It has worked out well and you can see pics here: https://www.hearth.com/talk/threads/new-jotul-f55-installed.115534/ It barely gets warm under this stove... the cat sleeps under there all the time.

I had a local glass place get it for me and it was <$100. I got exactly the size needed to meet code, but if I was to do it again, I would probably go another 2" out just to catch more dust/debris.

 

[trucha]

Thanks for the info guys. I still can't find out if there is a thickness requirement. I did read one document that said 24 gauge for steel but I forgot where I read this. Also, I still can't find any mention of hearth requirements for the Morso or Jotul stoves. I looked at the brochure and the individual stove manuals for both. Hearthstone has a lot more info in their brochure than the other two.

 

[Holzstapel]

The Jotul hearth requirements are stated in the owner's manual. Here is what Jotul says about the F55.

"4.1 Floor Protection


The Jøtul F 55 requires one of the following forms of hearth protection if not installed directly on concrete poured on earth:

1) Any UL, ULC, or Warnock Hersey Listed Type 1 hearth board.


2) Any noncombustible material.


No Bottom Heat Shield is required in either case."

 

[firefighterjake]

Trucha . . . If you post the exact make and models that you are looking at we might be able to give you a little more guidance rather than general statements on the hearth requirements. Brochures will not typically have the info you are looking for . . . manuals typically will.

 

[trucha]

I have looked at brochures and manuals and not all list an R value requirement for the floor especially Morsi. I think the Morsi stove I am looking at is the 3610 which is their largest stove. Maybe all Morsi models are ember only? The other models I am looking for are the Jotul F series line (45,50 and 55) as well as the jotul Oslo or Castine(much smaller). I also think hearthstone makes a nice stove that doesn't have the soapstone (not really into the look of soapstone) but that does require a r value rated hearth.

Another consideration is that I would like to have the stove stick out as little as possible from the wall so a stove that is wider than it is deep would help.

I am definitely leaning towards a ember only hearth as I would like to just put a sheet of metal under my stove and not deal with making a new tile hearth or ripping up the floors underneath. If that will not work I want to just take a piece of durrock and attach the metal to that.

Thanks for all of your help and interest! The last stove I bought I did no research and just bought the one I liked and found out later that there were better options. I don't want to make the same mistake again.

 

[begreen]

Morso 3610 hearth requirements are on page 9

For Installation on Combustible Floors
Non-combustible floor protection must be placed beneath the unit. The floor protection in front
of the stove must have a minimum insulative R-value of 0.8 (English units). The floor protection must
extend as follows.
U.S. installations: 16-in beyond the front and 8-in beyond each side of the fuel and ash
doors, beneath the chimney connector and 2-in beyond each side.

 

[trucha]

I still haven't found any thickness requirements. Anyone know what they are? I was at the stove shop yesterday and the person helping me found the manual for the jotul F55 and pointed this out to me.

The Jøtul F 55 requires one of the following forms of hearth protection if not installed directly on concrete poured on earth:

1) Any UL, ULC, or Warnock Hersey Listed Type 1 hearth board.


2) Any noncombustible material.

He took that to mean that you need an R rated hearth. I am not so sure. He said that type 1 hearth is one that has a R value of 1.0 or greater. I thought that was type 2. Anyway, any help? Thanks.

 

[Holzstapel]

I take that as meaning if you want to use the Type 1, you can. If you want to just use any non-combustible material, you can do that too. The manual is giving you a choice. I don't think there is a thickness requirement when dealing with 'ember protection'. If the ember protection is made out of a non-combustible material, then you are covered with choice #2. I was at my Jotul dealer last night and asked him if the Morso Steel Hearth Plates can be used under the F55. These hearth plates are 2mm thick and provide ember protection. He said they are ok to use.

 

[ccg36]

Type 1 is ember protection only, R value is 0.


Any non combustible material. Stone, tile, steel, glass. If tile or stone with grout lines, underlayment needs to be non combustible in case grout cracks. Cement board for example.

Oslo is ember protection only. Mine sits on my bluestone hearth with a piece of .078" steel 19" wide in front on the floor.

You can find the manuals with requirements on Jotul's and morso's website. Just takes a little research on your part.

 

[begreen]

A typical commercial type 1 hearth pad will be a base of plywood, then cement board, then grouted tile. The cement board will have an R value of .26 or .39 most commonly and 1/4" tile has a minor added R value of .02.

 

[firefighterjake]

As mentioned . . . non-combustible is just that . . . non-combustible . . . no R value, specific thickness, etc. needed . . . only that it be a solid (i.e. no cracks) surface and not be combustible -- glass, cement, metal, stone, tile, etc. would all work.

 

[Holzstapel]

My wife and I went out and got a piece of 11g steel and had it powdercoated red. This was going to be our hearth for the F55. It satisfied the requirements in the manual, it got the "OK" by the stove installer and the building inspector gave it the go ahead. I cost us $200 in total and we thought we were good to go.

The Mason who did our stucco took one look at the hearth plate and thought it was a joke. He insisted that we recess tile into the floor and have a flush mounted hearth the width of the chimney. He said he would cut out the floor, install the tile and grout for $150 if we bought the materials. We gave him the go ahead and he did a great job on the hearth.

After firing up the F55, we realized that having such a small hearth under that beast would have been scary. The tile under and around the stove is well over 125F when its running and I measured 150F on the tiles in front of the stove. The tile hearth wins by a longshot.

A $200 mistake, but we will find a use for it somewhere - perhaps under the Chimnea.

 

[jeffesonm]

I too have noticed it gets quite hot in front of the stove. Not so much the glass hearth extension, but the wood floor just beyond. I think it's all heat radiating from the glass, as directly under the stove never gets that hot. That's actually the cat's favorite spot to sleep.

 

[begreen]

I would expect that 150F in front of a stove is within tolerance for an ember protection only hearth. It's not that uncommon to see that as a wall temp behind stoves either.

 

[Bobde1234]

On a sort of related topic, I spoke with jotul a technical person today regarding combustible wall, and he told me that without a shield, the unprotected walk could reach 117°f + ambient temp ( 117° + 62° Room temp example = 179°f) and still be safe. He said it could be uncomfortable to touch. So 150°f on the floor seems to fall inside that zone. Does that sound acceptable to the experienced guys/gals here?

 

[begreen]

What happens if the room temp is 72ºF? Is 189º safe? I don't tink so Lucy. Pyrolysis occurs over time. 90º over ambient is what I have heard for a safety limit.

 

[Bobde1234]

Yeah that was straight from the guy at jotul North America. Adding a metal plate 1” off the wall seems like a very cheap form of safety. Btw, what do you think about me making a 5x10 notch in the bottom of the wall heat shield for the furnace heat register (not a return unfortunately)?