New woodstove install... Thoughts please...

[kketterer]

Hi Guys,

I have had a whitfield pellet stove in the house for a while now, But I just purchased my first wood stove for my small 20'x20' workshop. It is nothing fancy, Just a standard boxwood BX26E.

1) I plan to install in the corner, the walls are MDF chipboard, I was planning on covering the walls around the stove with 1/2" Durock as a heat barrier so that I can place the stove closer to the walls than 36". Should I leave 1" airspace between the backerboard and the wall?

2) There is no finished insulated ceiling, do I still need to use the insulation shield/chimney support, or can I just transition from the stovepipe to triple wall stainless and go through the roof with the Flashing and roof support??

 

[kketterer]

I found this setup....

I believe it should work well.

http://www.idealtruevalue.com/servlet/the-4233/Detail

 

[RPK1]

Hi Guys,

I have had a whitfield pellet stove in the house for a while now, But I just purchased my first wood stove for my small 20'x20' workshop. It is nothing fancy, Just a standard boxwood BX26E.

1) I plan to install in the corner, the walls are MDF chipboard, I was planning on covering the walls around the stove with 1/2" Durock as a heat barrier so that I can place the stove closer to the walls than 36". Should I leave 1" airspace between the backerboard antd the wall?

2) There is no finished insulated ceiling, do I still need to use the insulation shield/chimney support, or can I just transition from the stovepipe to triple wall stainless and go through the roof with the Flashing and roof support??

1) Yes you should leave a 1 inch air space between the Durock and the MDF board. Is the floor concrete? If not you will need something like Durock on the floor also.
2) You may have to use the insulation shield/chimney support. It may be the only way to transistion between the stove connector pipe and the stainless steel chimney. The stove connector pipe must be at least 18" from combustibles (wood rafters etc.) If you have a cathederal type ceiling you may have to build some type of structure to support the the chimney and stove pipe. If you have ceiling joists you could install cross pieces btween the joists to support the chimney support. Good Luck

RPK1

 

[RPK1]

Hi Guys,

I have had a whitfield pellet stove in the house for a while now, But I just purchased my first wood stove for my small 20'x20' workshop. It is nothing fancy, Just a standard boxwood BX26E.

1) I plan to install in the corner, the walls are MDF chipboard, I was planning on covering the walls around the stove with 1/2" Durock as a heat barrier so that I can place the stove closer to the walls than 36". Should I leave 1" airspace between the backerboard antd the wall?

2) There is no finished insulated ceiling, do I still need to use the insulation shield/chimney support, or can I just transition from the stovepipe to triple wall stainless and go through the roof with the Flashing and roof support??

1) Yes you should leave a 1 inch air space between the Durock and the MDF board. Is the floor concrete? If not you will need something like Durock on the floor also.
2) You may have to use the insulation shield/chimney support. It may be the only way to transistion between the stove connector pipe and the stainless steel chimney. The stove connector pipe must be at least 18" from combustibles (wood rafters etc.) If you have a cathederal type ceiling you may have to build some type of structure to support the the chimney and stove pipe. If you have ceiling joists you could install cross pieces btween the joists to support the chimney support. Good Luck

P.S. I just saw your second post. That pitched roof kit should work well

RPK1

 

[kketterer]

Thank you sir.

When I install the backerboard with the 1" gap, I was thinking... Can I use 1"x1" wood, or do the Spacers also have to be constructed of a noncombustable material, such as a couple of strips of backerboard.

 

[LLigetfa]

Spacer need to be non-combustible. Better not to use continuous strips either but rather small spacers that allow air movement in all directions.

 

[kketterer]

Spacer need to be non-combustible. Better not to use continuous strips either but rather small spacers that allow air movement in all directions.

Good call on the small spacers. I did not think of that.

 

[myzamboni]

I used pieces of 1" aluminum square stock for spacing. Some poeple use cermic insulators or pieces of copper piping.

 

[Gooserider]

Moved to the Hearth Room, where stove installs go...

Be sure to check manual, If you have a combustible floor, you will probably need at least a non-combustible hearth pad of a size specified in your manual, and possibly additional insulation depending on the manufacturer requirements.

Gooserider

 

[CWYfire]

Could someone explain using copper couplings as spacers? Do you just run a drywall screw through the middle of them into the studs? I thought copper would conduct heat straight to the combustible sheetrock surface behind the Durock? I am to that stage of putting up the heat shield behind and on the sidewalls. I thought you had to cut strips of Durock and place a couple 1/2" pieces behind the outer Durock.

 

[Gooserider]

Could someone explain using copper couplings as spacers? Do you just run a drywall screw through the middle of them into the studs? I thought copper would conduct heat straight to the combustible sheetrock surface behind the Durock? I am to that stage of putting up the heat shield behind and on the sidewalls. I thought you had to cut strips of Durock and place a couple 1/2" pieces behind the outer Durock.

Code says that you have to have a 1" gap between the "clearance reduction wall" and the "combustible wall", and that the spacers creating the gap have to be made from non-combustible material, but don't go into detail about just what the material has to be, and list metal as acceptable... The important thing is that you will get a cooling convective airflow through the gap via the (code required) openings at the top and bottom of the wall, which will adequately reduce the amount of heat transferred to an acceptable level - remember that you are primarily blocking radiant heat, so the amount of heat conducted by the copper or other spacer material would be negligible - and the primary heat concern isn't so much the sheetrock wall surface, but the studs behind it.

In other words, your question is a good one to ask, but it doesn't seem to be a problem, so as long as your spacer material isn't combustible, you can use whatever works easiest for you, and fits your budget best. Copper couplings are just one of many options - cheaper yet, but slower to produce is 1" lengths of copper pipe. Other options include blocks of scrap Durock (experience suggests making them at least 1" on a side to reduce the risk of splitting them) metal channels, stacks of washers, and so on - anything that will give you a 1" gap and won't burn... Frankly, if I were doing the job I'd go with scrap Durock, but there is no real requirement to use any particular method (however it never hurts to run your plans by your local inspector and get approval first - their approval trumps code unless you want a battle...)

Whatever sort of spacer you use, yes, you do drive the screw through the center of the spacer into the studs. (Use the special Durock cement board screws if possible to minimize damage to the surface of the cement board) In order to make it easier to line up the spacers on the screws, I've seen some people suggest pre-driving the screws partway into the cement board, and then taping or gluing the spacers in place over the screws to keep them in position while attaching the assembly to the wall.

Gooserider

 

[CWYfire]

Thanks Gooserider

That was my next question. How would be best to keep these copper couplings in place while screwing 40+ screws per sheet of Durock to the wall and not have to worry about the couplings moving or falling off and having to take everything back down to put them back in place.....

I was thinking what might be easiest is ripping strips of Durock (about 2-3" wide) or even cutting those strips into shorter blocks so that air can even move across ways behind the shield and screwing two thicknesses of 1/2" Durock to the studs for the 1" void. Then either screw the larger sheets of Durock to those strips or all the way through to the studs.

My questions:

1. Should I use 1 1/4" Durock screws attaching the Durock sheets only into the strips?

2. Or should I get longer screws (say 2" so at least 1/2" penetrate the studs) and attach the sheets through the strips and into the studs?

3. I was concerned that the longer screws would be a heat conductor directly into the combustible wood studs.

4. I was also unsure if the shorter ones would hold the weight of the sheets that will also have tile if they are only attached to the Durock strips?

I would appreciate any expertise and guidance on these issues as I am planning on building my heat shields tomorrow, (on Sunday).

Thanks
Ed

 

[Gooserider]

Thanks Gooserider

That was my next question. How would be best to keep these copper couplings in place while screwing 40+ screws per sheet of Durock to the wall and not have to worry about the couplings moving or falling off and having to take everything back down to put them back in place.....

I was thinking what might be easiest is ripping strips of Durock (about 2-3" wide) or even cutting those strips into shorter blocks so that air can even move across ways behind the shield and screwing two thicknesses of 1/2" Durock to the studs for the 1" void. Then either screw the larger sheets of Durock to those strips or all the way through to the studs.

First off, I haven't built one of these - my stoves are up against non-combustible walls, so it hasn't been an issue... That said, I'd probably only go with about a 1" square block, rather than 2-3" - big enough to not break when screwing through it, small enough not to impede airflow, and then use some sort of glue to hold the blocks in place, and possibly predriving the screws partway in.

My questions:

1. Should I use 1 1/4" Durock screws attaching the Durock sheets only into the strips?

I wouldn't bother.

2. Or should I get longer screws (say 2" so at least 1/2" penetrate the studs) and attach the sheets through the strips and into the studs?

I would use the longest screws you can get, as the Durock is pretty heavy, and you want to have good support on it. Remember you have about 2" of material to go through - 1.5" of Durock, plus your sheetrock before you even GET to the studs, so I'd probably want at least a 3" screw.

3. I was concerned that the longer screws would be a heat conductor directly into the combustible wood studs.

As mentioned earlier, not a particular issue, at least that's what the code implies. The amount of heat that will actually get to the screw, then penetrate down its length to the stud would be negligible in terms of the thermal mass of the stud.

4. I was also unsure if the shorter ones would hold the weight of the sheets that will also have tile if they are only attached to the Durock strips?

Exactly - you want some serious support for at that sort of weight - 3"+ screws and being the paranoid sort that I am I'd probably go with an 8-12" spacing going into the studs, especially around the edges.

I would appreciate any expertise and guidance on these issues as I am planning on building my heat shields tomorrow, (on Sunday).

Thanks
Ed

No problem - hope your project comes out well, post up some pics when you are done - (We likes Pikshure's here... :lol: )

Gooserider