# Add stone to the top of Jotul Wood stove



## tsquini (Jan 6, 2011)

I have a cast iron stove. It heats and cools off quick. I am looking to find a way to retain more heat. I was thinking of adding a 1 inch think piece of granite stone of the top of the stove to help retain heat. I am not sure if this would be a good or bad thing to do. It seems good. But, it will change the performance of the stove. Has anyone tried it and if so how has it helped or hurt?


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## jotulguy (Jan 6, 2011)

There was a post here recently where someone put a slab of soap stone on top of their steel stove. He has some burn time issues and wasnt getting as much heat off the stove. Not to mention keeping more heat in the stove is a risk. How much space are you trying to heat? Was this stove sized for your install? Tell us about your wood and stove top temps when burning.


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## tsquini (Jan 6, 2011)

It is the primary heat source for a 1,300 sqft house, it does very well. It is a great little stove.  I keep it running around 400 - 450. I can get it to run through the night so in the AM there is still a good bed of coals. The surface temperature of the stove will drop to around 200. I was thinking that a piece of stone on the top would help radiate more heat during the night.


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## bostock (Jan 6, 2011)

i agree with JOTULGUY - probably a stove-size (and burn-time) issue, and not an issue of what material you have. Im no scientist, but i would think whatever heat is "held" and given out later at the back-end of a cycle, is heat that is "stolen" and absorbed during the front-end of the cycle...in which case, material won't matter. BTU's are BTU's....the surface material should only affect WHEN they are given out to you, not HOW MANY are given out to you. Thats just my intuition though, founded in absolutely nothing at all


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## leeave96 (Jan 6, 2011)

You may find that adding a stone to your stove will suppress the heat output - not unlike a blanket of insulation.  I added three soapstones to the top of my soapstone stove and my stove top temperatures dropped over 100 degrees.  If your home is well insulated, rely on that to hold the heat rather than adding stones to the stove.  Try to get the heat off the stove and into the room.  With regard to soap stone stoves, one way to think about them is that the stones sort of act like a thermostat.  They absorb heat to prevent spikes and release heat to prevent dips in heat output.  That's why folks like the even heat from them.  If you add stones to your stove, I think that would be the only benefit you would get.

Good luck,
Bill


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## logger (Jan 6, 2011)

As mentioned, someone on the forum has done this, but I dont recall the outcome making that big of a difference.  Cast iron shouldn't cool off all that quickly, but Im sure with a smaller stove the time is even shorter.  Be thankful you didnt get a steel stove.  Hopefully the guy with the slab of soap will chime in here.  He added it to the top of his Jotul Oslo, so its similar to your setup, but a little larger.


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## firefighterjake (Jan 6, 2011)

tsquini said:
			
		

> I have a cast iron stove. It heats and cools off quick. I am looking to find a way to retain more heat. I was thinking of adding a 1 inch think piece of granite stone of the top of the stove to help retain heat. I am not sure if this would be a good or bad thing to do. It seems good. But, it will change the performance of the stove. Has anyone tried it and if so how has it helped or hurt?



Don't know if I'm "that guy" that folks are talking about . . . but I added a slab of soapstone to the top of my Jotul Oslo . . . knowing full well that it probably would not make much of a difference, but would be unique and pretty to look at . . . I did take the precaution of also putting the slab up on four small 1/4  inch blocks of soapstone so that there is an air gap between the top of the stove and the stone since I was a bit concerned about the stone affecting the insulation of the stove.

The result . . . the stone retains a bit of heat . . . but not much longer or hotter than the actual cast iron. The idea of using this as a heat sink doesn't pan out since there really isn't enough mass . . . however, it is pretty cool and gives my stove a unique look. I haven't noticed any change in the way the stove performs -- good or bad -- but then again as stated I also have the stone sitting above the stove top.

If you do a search you'll probably find some pics of my set up.


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## marine5068 (Jan 6, 2011)

The thick slab of granite or soapstone would be called a heat sink.
This is simply any large dense object such as a concrete floor or brick/stone backer or rear wall near the stove or heating appliance that will warm up slowly and hold and dissipate heat back for a longer period of time.
I have my stove sitting on concrete and stone raised hearth and am building a solid concrete/stone wall behind it for this purpose. Never heard of anyone putting stone on top of the stove but in theory it will work.
Good luck.


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## branchburner (Jan 6, 2011)

My experience is similar to Jake's - not enough mass to make a real difference. If you did have enough mass to make a real difference, it might affect your stove's performance, as your firebox might be too small to burn efficiently with all that mass.

I have two 10x16x3/4 slabs of soapstone I put on my cast iron to bake on. The temps don't get as high as the cast, but the stone hold and radiates the heat very well. Be careful with granite - it is more prone to cracking by thermal shock.


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## firefighterjake (Jan 6, 2011)

Found my original thread . . . with pics.

https://www.hearth.com/econtent/index.php/forums/viewthread/45549/

https://www.hearth.com/econtent/ind...27258_ETs8MnzzpB18rY5seMlo&thumb=1&board_id=1

In looking back at this thread I realized my spacers were 1/2 inch . . . not 1/4 inch.

Also, I have had the fire die out on me since posting that and found that the stone does stay slightly warmer than the cast iron . . . but only slightly warmer . . . the heat it retains and gives off is not notable.


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## Adios Pantalones (Jan 6, 2011)

What would be interesting is a way to couple that heat sink to the output of a blower.  That way the heat definitely gets out of the stove- the stone just acts as a buffer to take up the heat and re-radiate it.


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## geoxman (Jan 6, 2011)

I have a 4ftx2ft piece of marble on top of my defiant/encore and I really like it because of the extra shelf space on top of the stove. It is great for drying things and it still boils the kettle. The only downfall for me was I lost the top load. I got mine for free because someone threw it out but you could get a scrap piece of granite cheap from a counter top maker.


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## Backwoods Savage (Jan 6, 2011)

Rather than placing the stone on top of the stove, why not just place it next to the stove? Maybe even behind the stove. Then it could absorb some heat. However, water works even better than stone for this.

fwiw, I have some small soapstone blocks on our stove top and find the temperature difference to be about 50 degrees lower between where those blocks are placed vs. the bare stove top.


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