Hi, my name is DennisP. Just heard about this website and was interested in getting some information on how to build a floor/pad to put a wood stove on. We looked at some stone and tile at one of the local stores. I’ve got quite a few books at home on home repair and maintenance, but none that discuss installation of flooring for a wood stove.
Anyone have any idea on where I get get some information on how to build one of these babies?
Thanks,
Dennis
Replies
Dennis .... Provided your subfloor can handle the load..... there are prefab slabs of heat resistant material that both spread the load over the subfloor and act as a fireproof subflooring. The are approx 4' x 4' x 1.5" high & have a nice finish (faux brick) on the top with a black synthetic wood border. I laid my on top of the carpet , placed the stove on top (Heavy duty Jotul) and installed the chimney pipes. Very easy, looked good and was in code for Marlborough, Mass.
Good luck
Dennis. Many years ago we heated entirely with wood. Used several floor coverings as material permitted. For an old coal stove that would get cherry red on the face, we had a sheet metal base, then concrete block laid sideways with a cap over the top of brick. The brick got warm but never hot enough to concern us about combustion. In another application we picked up from an old hardware, a wood stove "pan". Decorative painted metal that was pressed around 3/8's inch of something. Could have been a non flamable material, don't really know. That one had a Fisher stove on top of it. Stood up maybe on 6" legs. The under side of that never got too hot either. Most of the heat goes up or radiates to the sides. With the air movement under the stove and the firebrick on the bottom of (inside) the combustion chamber, the metal pan was there to protect from burning embers falling outta the door. We used some salvaged sidewalk sandstone under another. Whatever you do, be sure to give it room in your bare feet. And pay attention to weight you put on the floor. Additionally, be concerned with distance away from combustibles to the back and the sides.
__________________________________________
Remodeling Contractor just outside the Glass City.
http://www.quittintime.com/
Dennis, the prevab units work great and are the proper dimensions. Remember that the dimension are specified by code. there will be a metal label on the back of any new woodstove that will specify stove placement. If you want to build the hearth yourself you must start with a solid sheat of wonderboard (cement board) so any ember don't slip thru the cracks of the finish material and onto the subfloor. You can then build up with brick, tile or any non-combustable. Masonary fireplaces must have a hearth extending 20" beyond the opening. Woodstoves might be 16" but check your local code. I don't have mine in front of me.
Dave
If a tree falls in the woods and nobody hears it is it still lumber?
I heat our place with wood; I run a Jotul #3 and burn between 7 & 10 cords a year, depending on the temperature.
The hearth is constructed directly on top of the finish floor in the following manner:
You will also probably want to build a heat-shield on the wall behind and/or next to the stove, depending on its placement. This allows you to reduce the distance the stove must be from the flammable wall from 48" to 24" (check your stove's homologation certificate and local regulations for the exact distances). The heat shield must not touch the wall and must have air circulation behind it to remove heat build-up.
One suggestion I'd make is to build the hearth a bit bigger than code requirements if you've got the room; it's nice to have the space to dump snow-covered logs, wet winter boots & so forth near the stove to dry out. Do also take the trouble to seal your slate or tiles (if they're not a gloss finish); it will make cleaning the ashes off a lot easier.
Dinosaur
'Y-a-tu de la justice dans ce maudit monde?
I'd like to bring this back to life.
I need to construct a 30 sq ft pad for a woodstove in our large, old home. The pre-fab units may work, but we'd like to pick the tile. Does anyone know how they supposedly reach the ~2.22 R factor in an inch and a quarter in these things? They must use some fabric between the particle board on the back and the tile/Durock(?) sandwich on the front.
I'd like to make something that will float on our 113 yr-old flooring, but not be 3" thick. The guy at the stove store said "two sheets of Durock beneath tile should be fine." My friends at the lumber store aren't so sure, and they don't know what the k or R values of their materials are.
Is there some fabric (asbestos replacement) that is used in the sandwich? Anyone know what it's called?
thks a bunch--Larry, Butte MT
It doesn't have to be 3" thick; just 2". I use 1.5" patio tiles rough cut to fit in a form made of finish-grade trim; then I fill to 2" thick with concrete/Full-Flex and set the tile/slate/whatever on top of it flush with the form. Finish the form as trim any way you like.
If you want it to 'float' on top of 113-year-old floors, you're gonna need some way to prevent it cracking as the floor moves. This is not gonna be easy; nothing I can think of will be guaranteed. You might try setting rebar grids into the concrete (no patio tiles here; full pour 2" deep); I don't know how that would affect heat transmission, tho. You might also try floating several lifts of concrete with a few layers of Fibreglas mesh set into it. Maybe just four layers of Fibreglas-reinforced ½" backer board glued together (or not!--there's a thought) with Full Flex or similar. All this is brainstorming for the 'float' problem. Take your pick....Dinosaur
'Y-a-tu de la justice dans ce maudit monde?
Thanks for the reply. Problem is... I wonder how to meet the R or k rating asked for by the stove manufacturer? I don't know what the values are for a cement mixture and patio blocks, but Durock has a k value of 1.92. That translates to needing 4.25" of the stuff to reach an R value of 2.22 requested by the stove (Quadrafire). My guess is that portland cement products are not very different. (I am sure that if I followed your design, I'd not torch my house, even if it didn't meet the R value spec!).
I'm on something of a quest to figure out what product will give the higher R rating... my friends at the lumber store suggested 1/2" hard foam (R 7 per inch) beneath 2 or 3 layers of Durock, but they realize that wouldn't meet the spec for non-flammable materials.
I've still got some calls to make before I punt and use a pre-fab slab. I think I'll convince my stove guy to slice a sample of one in half! Larry
The best information on stove and fireplace installations is contained in a 28-page booklet published by the Association des professionnels du chauffage à combustibles solide. Their phone number is (514) 270-4944; the fax is (514) 270-5488. (This info comes from my 1989 edition which is somewhat out of date.) I assume the booklet is published in English, but my edition is in French. Someone there should speak English, if your French is not at the functional level--they're in Montréal, also known as Québec's English Ghetto....
This is the reference we use here for intallations that meet both the NBC and the insurance companies' requirements--which are sometimes stricter, BTW. Below is a scanned spread illustrating two different ways to built a sub-stove fire floor, depending on the homologation of the stove in question and the distance of the bottom of the stove to the floor (ie, length of legs).
Remember that circulating air in the heat shield is important to keep it cool, whatever it is. The solid 2" concrete job I described is appropriate for modern stoves with integral bottom heat shields. These illustrations show how to deal with an older stove that throws off too much heat through its bottom plate.Dinosaur
'Y-a-tu de la justice dans ce maudit monde?
I don't know the R value of rock wool but it is fire proof. You can direct the flame from a propane torch directly on rock wool with a penny laying on the rock wool and it won't catch fire but the penny will melt.
An obvious addition to my posts would have been that AIR seems to be the only way to reach a higher R value. Clearly, setting open concrete blocks on their side is the way to go (thus a higher hearth). The problem with rock wool, is that all of the air will squish out of it if you lay 500-700 lb of stove and tile on top of it!
Still looking for air packaged in a thin, non-flammable substance!
Larry
I found what I was looking for, now I have to find someone who can get it for me. The product is Micore, it comes in 160 and 300 versions in thicknesses from 3/8 to 3/4", made by US Gypsum. I guess it's a non-flammable, sound deadening panel product used for cubicles and stove hearths(!) The 160 version is only 16 lb/cu-ft, has a k value of 0.35 giving an R value of 1.43 in 1/2". The 300 version is 24 lb/cu-ft, has a k value of 0.458, giving an R value of 1.09 in 1/2". I think that the 300 version is most likely used for hearths, as it's harder and stronger. Just over 1" of the stuff with a tile cap is what I'm looking for--the equivalent insulating value of 4.3" of Durock or brick.
Hope this helps someone else.--Larry