Skamotec for alcove installation

[NKMatt007]

My wife and I are in the process of building a house and bought a Jotul Oslo for installation in an alcove. We have been tasked with designing the "firebox" and wanted to run it by you all for ideas/piece of mind. In order to meet clearances, the manual states that the side and rear wall protection must be elevated 1 inch off the walls and floor. However, has anyone used Skamotec 225 to eliminate the requirement for the one inch air gaps? (The brochure claims this is tested and safe)

Our plan is to create a 5 sided box (open on the front) using the Skamotec material that the wood stove will sit in. We will meet the required clearance to combustable material as long as the Skamotec is considered a protected surface. We plan to line this box with thin brick to get a fireplace look.

I uploaded a pic of the bump out that the stove will go in as well as our design drawings.

Thanks in advance!

 

[begreen]

Sounds dubious. Another concern is the wood lintel over the stove top. If the goal is to make the alcove non-combustible a better plan might be to frame the alcove with metal studs and sheath it with cement board underlayment for the brick.

 

[webby3650]

I’m also concerned with that header height, also the width, your side door won’t be easy to use.

Why do you want the stove back in an alcove like that? Looks like the original plans called for a cheap Fireplace and you’ve substituted it with a stove? If you were to bring the stove into the room it would be safer and heat much better.

At least, you should remove the studs up to the header. Some can lights shining down on the stove would be cool. Also, you’ll need to offset around that truss that’s centered on the chase. Architects always miss that one!

 

[begreen]

While skamotec is tested for insulation value and high heat it is not tested for clearance reduction or protection of combustible surfaces by the stove maker.

 

[NKMatt007]

Thank you both for the replies! How tall the alcove must be is a little unclear in the manual, which says the height of the wall protection must be 48" but then goes on to say the minimum ceiling height off the top of the stove in a protected installation is 15" (this would only be 43 1/2"). Am I misreading this? We can go with 48" just to be safe. I'll be out at the house this weekend and will measure how high that header is. I know it is at least 48" but we can move it or replace with metal if not.

We told our builder and the architect all along that we wanted to do a wood stove in the bump-out and that's how it ended up getting built. I'd love to pull the stove out into the room but we do have a space issue in the living room. Removing the studs up to the header is a solution but I prefer the fireplace look if we can make it work. Another thing is that the stove will mostly be out in the room (see the top view drawing that I attached). We should be able to open the side door unimpeded but we can lock the side door if we have to. The manual states it should be locked for alcove installation anyways.

Skamotec 225 is approved as a wall protector under UL 1618 and is intended for installation in accordance with NFPA 211.The manual references NFPA 211 as the standard that should be followed when installing the wall protection. I think (famous last words) the only thing we are trying to do differently is with avoiding the 1" air gaps. It's not so much the 1" off the wall, we can do that, it's the 1" off the floor. How do you make that look good? Won't there just be a visible gap between the hearth and the walls?

 

[begreen]

New materials continue to show up. If you you can get a variance from the local inspecting authority for clearance reduction with the Skamotec 225, go for it. This is the first time I have seen this product and it could be that the next revision of NFPA211 will get amended to include it. Maybe send your drawings and stove documentation to Skamotec and have them provide you with a letter of certification?

There are several past alcove installation threads here. Search on Alcove in the title only for examples. Several employ the NFPA 211 ventilated wall for clearance reduction. It's not all that obvious when done right. Though what you are constructing is not really an alcove, it is a simulated fireplace.

There's not much built there already. If the Skamotec is expensive I'd probably tear it out and rebuild using metal studs. Then the clearance issues become moot except for the back wall and it appears that you have the stove placed far enough forward to meet the rear clearance if the stove has the rear heat shield and double-wall stove pipe is used. How much will it cost to use the skamotec 225?

How is the stove being vented and at what point will it transition to chimney pipe? Will this be at the lintel height?

 

[begreen]

Skamotec 225 is approved as a wall protector under UL 1618 and is intended for installation in accordance with NFPA 211.The manual references NFPA 211 as the standard that should be followed when installing the wall protection. I think (famous last words) the only thing we are trying to do differently is with avoiding the 1" air gaps. It's not so much the 1" off the wall, we can do that, it's the 1" off the floor. How do you make that look good? Won't there just be a visible gap between the hearth and the walls?

I just visited their site and downloaded the brochure. They are claiming a 50% clearance reduction which is below the 66% with a ventilated wall, but the same as a full brick wall. In addition to getting a certification from Skamotec, having a letter of endorsement/approval from Jotul would help a lot in making a case with the the inspector.

I am curious about how one works with and finishes this product. Have you inquired about how good a backerboard skamotec 225 would be for the brick veneer?

 

[kennyp2339]

I'm just having trouble understanding the whole notion of new cons and building a alcove while using a free standing stove, I mean why bother going through all of that extra work to take a stove that was designed to radiate heat and tuck it into essentially a hole in the wall, reducing the heating effects the stove was designed to do.
If space is the issue (and I can see how that could be with a chimney in a chase) why not install the ceiling support box at normal ceiling height in "the alcove" and build a nice hearth with a nice stone back wall to accent the stove, hearth, & room then you reduce you clearance worry, you get better radiant / convection heating off the stove and cleaning / maintenance is much easier (including access to the rear blower for cleaning and oiling)

 

[NKMatt007]

I just visited their site and downloaded the brochure. They are claiming a 50% clearance reduction which is below the 66% with a ventilated wall, but the same as a full brick wall. In addition to getting a certification from Skamotec, having a letter of endorsement/approval from Jotul would help a lot in making a case with the the inspector.

I am curious about how one works with and finishes this product. Have you inquired about how good a backerboard skamotec 225 would be for the brick veneer?

View attachment 228299

We'll have 10 inches of clearance on the sides and 12 on the back. Manual says 6" to a protected surface so we will be exceeding that. If we can't avoid the air gaps then I think we will go with something like a durock. The skamotec stuff ain't cheap at $220 for 48x80". It has an R value of around 2.3. There YouTube channel makes it seem easy to attach half brick to the boards.

Our stove installer said the pipe can T into the back of the stove or come off the top. It will have to have some type of able because the stove will not be directly under the pipe.

How about our height clearance? The manual seems to say it's only 48" or 15" off the top of the stove. I'll also call Jotul to get some clarification on that.

 

[begreen]

By the drawing design, the side clearance on the door side is the issue. The position of the stove makes it look like the side door will be used, especially if this is not really an alcove install. The F500 is more pleasant to use as a side loader. Given the cost of skamotec, uncertainties, installation and finishing concerns, I'd still consider a rebuild with completely non-combustible framing, backerboard and finish. Then the installation is pretty straight-forward.

I thought about having a rear-exit. That would require double-wall pipe for clearances, but I am concerned about poor draft due to inadequate total flue height. The Oslo likes strong draft, especially if rear vented. Before going much further I would detail the complete stove install including where the chimney support occurs and total flue height to be sure the install and future stove operation don't have other challenges.