Hearth pad

[mikemc53]

OK, gonna be a first time wood burner. Expect some really dumb questions - and the first has to do with hearth pads.

I've skimmed through a few pages of the forum and looked at some questions in this regard already, but I'm still pretty foggy on this. Can one of those (very cheap) Imperial stove pads that are sold at Lowes and other stores for around $60, actually serve the purpose of a protective hearth pad, or would you need something else to go along with it?

The stove is an Englander, or actually a Summers Heat by England Stoves model 50-SNC13LC. The room that the stove is going in has hardwood floors so obviously there is a need for a pad. Just wondering about the pad that I mentioned (above) because I had seen in a thread about cheap temporary pads that a few members had mentioned that particular method.

Is it doable?

Thanks
Mike

 

[crazy_dan]

does the Manuel say anything about r-values or just ember protection?

It would work for a PE as it says for ember protection only.

 

[Alan Gage]

I've got the same stove and the manual calls for an insulation value of R2 under the stove; which seems a bit much to me but hey, it's what they want.

I laid down some steel studs that give a 4" air space, put a layer of dura-rock on top of that, then finished it off with 12" brick paving stones. First year burning and so far so good. Doesn't seem to get hot enough under the stove to warrant all that R value but it's better safe than sorry I guess.

Alan

 

[alexei27]

I have a summers Heat. Buried in the instructions are the words " for ember protection"...and it says a specific "r" value is not needed. I had to really search for this...but it's in there.

 

[bmwloco]

My "hearth pad" is a nice slab of granite, secured from a secret site near my home in the mountains of North Carolina.

It serves two purposes. First, it keeps the embers from falling onto the floor and scoring the hardwood. Secondly, it keeps our 16 year old chocolate lab from getting her head stuck under the stove, something her sister was very apt to do. They love to get as close to it as they can.

 

[edthedawg]

Since granite doesn't seem to have much of an actual R-value, the obvious questions are: 1 - what's under that granite? and 2 - what's above it?

 

[bmwloco]

Underneath, just a few patches of anti-scuff padding for the floor. Above, the shelf on the VC Resolute II. The stove actually sits on the fireplace hearth stone, behind it, the decommissioned and utterly useless gas logs my wife insisted on.

Three winters, no problems.

 

[Danno77]

I'm reading through the manual right now and I find the following regarding "floor protection"

You will not need any floor protection if your floor is constructed of a non-combustible material such as brick or concrete. If your floor is constructed with a combustible material such as hardwood, carpet or linoleum, you must place protection between the stove and the combustible material.
There are many floor and wall board manufacturers, and you should be very cautious in choosing the proper protection. The type board you choose should be U.L. rated and listed. After examining the area you plan to place your stove and determining it requires a board, the next step is to select the proper size. The stove you choose will determine the size board that is required. The approved protector board should be large enough to provide a minimum of eight inches (8”) behind the unit, eight inches (8”) on either side and sixteen inches (16”) in the front where the door is located. This stove requires a minimum of 48” x 48” floor protection.

If the appliance is to be installed on a combustible floor or a combustible floor covering, it must be installed on a 1” thick non-combustible millboard floor protector or a durable equivalent, with a “R” factor of no less than “2.” The pad must be installed beneath the unit, extending 16” (U.S.) on the side equipped with a door, and 8” on all other sides. The pad must cover any horizontal chimney connector runs and extend 2” beyond each side.
Alternate Floor Protection:
An easy means of determining if a proposed alternate floor protector meets requirements is to follow this procedure:
1) Convert specification to R-value:
i R-value is given – no conversion is needed
ii k-factor is given with a required thickness (T) in inches: R = 1/k x T
iii C-factor is given: R = 1/C
2) Determine the R-value of the proposed alternate floor protector:
i Use the correct formula given in step 1 (above) to convert values not expressed as “R.”
ii For multiple layers, add R-values of each layer to determine overall R-value.
3) If the overall R-value of the system is greater than the R-value of the specified floor protector, the alternate is acceptable.
EXAMPLE:
The specified floor protector should be ¾” thick material with a k-factor of 0.84. The proposed alternate is 4” brick with a C-factor of 1.25 over 1/8” mineral board with a k-factor of 0.29.
Step (a): Use formula above to convert specification to R-value. R = 1/k x T = 1/0.84 x .75 = 0.893
Step (b): Calculate R of proposed system.
4” brick of C = 1.25, therefore R brick = 1/C =1/1.25 = 0.80
1/8” mineral board of k = 0.29, therefore Rmin.bd. = 1/0.29 x 0.125 = 0.431
Total R = Rbrick + Rmineral board = 0.8 + 0.431 = 1.231
Step (c): Compare proposed system of R of 1.231 to specified R of 0.893. Since proposed system R is greater than required, the system is acceptable.

 

[edthedawg]

R2 is fairly easy to obtain without breaking the bank or your construction skill set too badly. Steel studs, Wonderboard/Durock, Versabond mortar, and some cheap HD tiles, and you're well on your way for probably $150...

 

[MontanaBob]

I too have an Englander 13. I built this pad using 3/4 " plywood then 1/4" air space then 1/2" durock then 1/4" air space then 1/2" durock and finally 1/4" slate tiles. Encased in Oak trim. Total cost about $165. Supposedly the air space gets me to the R2 value. This air sapce was created with 1/4" durock cut into furring strips. Everone told me I overbuilt it, but......

 

[ChipTam]

I considered using that Imperial stove board for my hearth pad but re-thought it and made my own hearth pad. You can figure that the 1/2" Imperial stove board has an R-value of around .42. Trying to find out information regarding R-values from Imperial is frustrating to say the least. The company gives no information about R-values at their web site and several messages left at their 800 assistance number were never returned.

I purchased one of their stove boards and, only then, did the installation information say that one layer of their stove board equals the R-value of one layer of 3/8" asbestos mill board (which is no longer made). Since my 20 year-old stove called for two layers of 3/8" asbestos mill board and requires an R-value of .84 I figured that the Imperial board has an R-value of about .42. As I mentioned, I returned the Imperial stove board and made my own pad. I must have required a larger size pad than you needed for your stove since I paid $130 for one pad. Two pads would have worked for me but I was able to make my own for much less.

ChipTam

 

[Pagey]

There's a section in this .pdf that will give you some good pointers on constructing your own.

(broken link removed to http://www.woodstove.com/guidepdfs/Plan) your hearth.pdf

If you want to go with something prefab (can get pricey), check out these folks:

(broken link removed to http://www.americanpanelhearth.com/Product) Line/default.htm

 

[Danno77]

I was hoping to use a homemade pad made of durock with bricks mortared on it. I’m getting the impression my R-Value wouldn’t be enough using that. Intuition tells me that should be adequate, but the numbers don’t look right to me.

Another nice thing about having a brick hearth would be the thermal mass of the thing. Is that something I should even worry about?

Advice? opinions? I'm looking at the same stove that the OP is.

 

[edthedawg]

3" brick + 1/2" Durock would give you about R 0.8. Thermal mass = yes. Insulation = no. Kinda makes sense - wouldn't want your insulation to have great heat retention properties...