contractor maybe misled by owners' manual (posted earlier in wrong forum)

[robman]

Hi
I have a 32" deep x 56" wide X 9' tall alcove where there used to be a fireplace and chimney. The chimney had issues so we had installed a lopi patriot stove and chimney liner and now for seismic upgrades have removed the chimney. We now want to reinstall the lopi to code. And at some future date, I'd like to have the flexibility of changing out the stove.

I have read and posted a few questions and think I understand what is needed but the contractors with whom I have spoken all seem to think I am going way over what is required. I would greatly appreciate answers to a few quick questions:

1) Distance to combustibles: Am I correct in that one layer of durock screwed into metal studs and then covered with ceramic tile does not reduce clearance to combustibles? That the only way to do that is with an NFPA211 clearance reducer?

2) 1" standoffs with the air gap at top and bottom for convection and then durock and tile allow for this reduction by 50%? (the contractor thinks that the standoffs, as described in the owners' manual, are only for mobile homes, which ours is not)

3) Durock or some similar material must line the entire alcove?

4) Are 2 layers of durock recommended over 1 for the hearth (floor) of the alcove? (The Lopi owners' manual only requires 1/8th or 1/4".)

Thanks

Rob

 

[begreen]

Hi
I have a 32" deep x 56" wide X 9' tall alcove where there used to be a fireplace and chimney. The chimney had issues so we had installed a lopi patriot stove and chimney liner and now for seismic upgrades have removed the chimney. We now want to reinstall the lopi to code. And at some future date, I'd like to have the flexibility of changing out the stove.

I have read and posted a few questions and think I understand what is needed but the contractors with whom I have spoken all seem to think I am going way over what is required. I would greatly appreciate answers to a few quick questions:

1) Distance to combustibles: Am I correct in that one layer of durock screwed into metal studs and then covered with ceramic tile does not reduce clearance to combustibles? That the only way to do that is with an NFPA211 clearance reducer?

In this circumstance the combustible behind the metal studs is the nearest combustible, so that may gain an additional 4" from the tile surface of the wall. If the wall cavity behind the durock was open at the top and bottom of this wall then it could conceivably be used for clearance reduction. But only if the stove manual permits this reduction. Normally there is no need for metal stud wall if the wall shield is used unless one desires more peace of mind, but Lopi is an exception. They even want a ventilated brick ceiling!

2) 1" standoffs with the air gap at top and bottom for convection and then durock and tile allow for this reduction by 50%? (the contractor thinks that the standoffs, as described in the owners' manual, are only for mobile homes, which ours is not)

A properly installed NFPA 211 wall shield allows a 66% clearance reduction down to as low as 12", if the stove manual allows for this. In some circumstances this distance can be shorter if the stove has been tested with a wall shield and this is listed in the documentation as the allowable clearance. A layer of full brick will achieve a 50% reduction, if allowable in the manual.

3) Durock or some similar material must line the entire alcove?

No, not for all stoves, some Lopi stoves are an exception. Again it depends on the installation and the stove. Some alcove installation require no clearance reduction and are ok to be clad with drywall. If a clearance reduction via an NFPA wall shield is permitted then the shield can stop at a prescribed distance above the stove unless the stove is connected with single-wall pipe and full protection is needed for the stove pipe as well.

The Patriot manual is unusual in that it has very detailed specs for a non-combustible alcove installation. This includes double-wall stove pipe and a completely shielded and ventilated alcove if one wants the Non-Combustible alcove clearances. It says:
Non-combustible alcoves must have:
walls and a ceiling that are 3 1/2" thick of a non-combustible material (brick, stone, or concrete -

see Figure 9). This non-combustible material must be spaced and ventilated at least 1" off of all

combustible materials (walls, ceiling, etc.) to allow air to move around the non-combustible walls

and ceiling. All other alcoves are considered combustible.

It definitely will be safe, but I've always found this onerous and overkill. I think Lopi is the only stove maker that has this requirement.

4) Are 2 layers of durock recommended over 1 for the hearth (floor) of the alcove? (The Lopi owners' manual only requires 1/8th or 1/4".)

No, one layer of Durock is sufficient for this stove.

I can understand the contractor's consternation. Lopi has some tough to meet requirements for their alcove installation. They are unusual enough that I might think of selling the stove and getting a different one with less stringent alcove requirements. Not sure if that is an option. Answers in context to your questions above. Hope this helps.

 

[kennyp2339]

I can understand the contractor's consternation. Lopi has some tough to meet requirements for their alcove installation. They are unusual enough that I might think of selling the stove and getting a different one with less stringent alcove requirements. Not sure if that is an option. Answers in context to your questions above. Hope this helps.

BG - this forum wouldn't be half as good with out members / pro's like you, just saying thanks and a job well done!

 

[begreen]

Aw shucks,, thanks. There are lots of good folks contributing here. I'm thankful to keep learning after all these years.

 

[robman]

Thanks BG. If I were to go to an easier or better alcove stove, what would you suggest? It would need to be top vented and for 6" flue.

I think I will probably go durock the 9' up and top of the alcove. Better safe than sorry. The contractor was under the impression that we could use distance to non-combustibles with the durock and tile without the 1" air gap. I believe that is incorrect.

The 4" wall thickness of steel studded walls is to allow for a row of 6x6 tiles around the opening, It gives me the spacing I need for that.

Will all stoves allow just one sheet of durock on the hearth (floor) and then ceramic tiles going to work for any stove on legs of at least 3 or 4"?

Thanks again. You are a great help

Rob

 

[bholler]

Thanks BG. If I were to go to an easier or better alcove stove, what would you suggest? It would need to be top vented and for 6" flue.

I think I will probably go durock the 9' up and top of the alcove. Better safe than sorry. The contractor was under the impression that we could use distance to non-combustibles with the durock and tile without the 1" air gap. I believe that is incorrect.

The 4" wall thickness of steel studded walls is to allow for a row of 6x6 tiles around the opening, It gives me the spacing I need for that.

Will all stoves allow just one sheet of durock on the hearth (floor) and then ceramic tiles going to work for any stove on legs of at least 3 or 4"?

Thanks again. You are a great help

Rob

Stoves will all have different requirement but there are many on the market now that need only ember protection on the hearth which one layer of cement board will be fine for.

 

[begreen]

Thanks BG. If I were to go to an easier or better alcove stove, what would you suggest? It would need to be top vented and for 6" flue.

I think I will probably go durock the 9' up and top of the alcove. Better safe than sorry. The contractor was under the impression that we could use distance to non-combustibles with the durock and tile without the 1" air gap. I believe that is incorrect.

The 4" wall thickness of steel studded walls is to allow for a row of 6x6 tiles around the opening, It gives me the spacing I need for that.

Will all stoves allow just one sheet of durock on the hearth (floor) and then ceramic tiles going to work for any stove on legs of at least 3 or 4"?

Thanks again. You are a great help

Rob

This depends on how large an area the stove will be heating and how it will be run. For example, assuming 56" between combustible walls it looks like a Quadrafire 3100 would just fit in there with no special wall prep or wall shield needed. It looks like a Regency 2400 would also work. I'm sure there are others too. But if the steel stud walls are already up and the distance to combustibles is more like 64" then you have a lot more choices. It depends on what you are looking for and what local dealers have available.

PS: Is there insulation between the steel studs and if yes, is it Roxul or fiberglass? Paper faced or plain?

 

[robman]

Thanks BG
You are really helpful. The steel studs are not yet up--putting them up will give me the room coming in from the walls to put the border of tile up. It is 56" between wood walls/cabinet sides. I had not considered insulating the steel studs but can do so, and if I do would use roxul which seems like a superior insulation. Is this recommended?

Thanks again

Rob

 

[begreen]

No need to insulate on an interior wall, but if the back is exterior then sure, use roxul. If you are basically just furring out the cabinet walls then maybe use 7/8" hat channel?

 

[robman]

Hi again and thanks again. Also a shout of thanks to BHoller for earlier comment about hearth. The fireplace was probably originally a coal stove and is in the center of the house. The back wall goes to the kitchen (they shared the chimney). Thanks again

Rob