Height of heat shield on side walls of alcove install

[CWYfire]

I have built an alcove in the shape of a Bay Window on the side of my house so my Century FW300007 sits back in it out of the way. The overall dimensions of the stove are 31 1/2 in.H, 26 1/2 in. W, 25 1/8 in.D. All of the specs can be found at (broken link removed).

The alcove dimensions to the 5/8" sheetrock are as follows:
Height of alcove is 88" with a 2"x12" header across the 78.5" opening that was the outside wall of the house. The alcove is 34.5" deep angling back to a 55.5" back wall. I am unsure how to give an exact angle and discovered that I have left my digital camera in a friend's car so can't post a picture till I get it back.

I have framed in the stove pipe ceiling box so that the stove will sit deeper in the alcove so the triple wall pipe is a bit farther away from the solid wood header in the small attic area above the alcove. As planned the stove will be sitting 12” from the sheetrock on the back wall. This means the stove will be about 10 ½” from the Durock heat shield in the back. Will this be a safe distance?

1. As I understand in building a heat shield I will strip the studs in the back wall with double 1/2" strips 4” wide Durock then covering the strips with 3’x5’ sheets of Durock over the entire wall, stopping shy at both the top and bottom a few inches for air circulation. Question: IS THIS CORRECT?

I have unable to find anything by the manufacture of this stove for an alcove installation.

Because the angular side walls are not the 26" distance specified by the manufacture for a corner install, I am planning to put the same Durock heat shield on the sidewalls. However I was hoping to only have to go part way up these rather than doing the entire walls.

2. Question: Can I just build the Durock heat shields on the side walls 6” above the top of the stove or must these cover the entire wall like the back?

3. Question: If it is OK to build shorter heat shields on the side walls how would it be best to cap off the top of the Durock with tile so the rough Durock edges do not show? Could I just let the tile overhang the Durock an inch or so to hide it or might there be some better way to cap it?

4. Question: Prior to putting the Durock shields over the sheetrock I guess I should tape and mud all of the joints on the sheetrock, CORRECT? Should I just use regular sheetrock mud to do this or is there a better material to use since this is going to be around such heat? Should I pull a thin coat over the all of the sheetrock to cover the paper on it?

Sorry for so many questions. But I am getting ready to jump on this tomorrow and I am hoping to get it right the first time around and have found that you within this forum are quite incredible to help each other get it right, even if the question has been asked a hundred times…. LOL

This is the kind of website that makes the www a truly wonderful asset.

Thanks,
Ed

 

[begreen]

The installation is in variance with the published specs for the stove which appears to be 15" from the back of the stove to the wall (from the addendum posted on VC's website). But don't panic, there is an exception granted in section 3 of the installation directions. With the heatshield, 12" from the nearest combustible is within the NPFA allowable clearance reduction. However, it would be good to get approval from the inspecting authority before proceeding just to avoid later hassles.

Normally the heat shield should extend about 6" above the top of the flue collar. Your method of construction is correct. If the alcove flares out, will any point on the rear of the stove be closer to the sidewall than 26"? By the dimensions provided, it doesn't sound like it. If not, no side wall shields are required. I would recommend laying out this on the floor with masking tape or a cardboard template to check.

As for trimming to the top edge, you can use a tile cap piece that has about a 1/2-3/4" ledge on it. Yes, firetape the sheetrock before adding the wall shields. Regular mud is fine. Behind the shields the sheetrock wall will be close to ambient temperature. Just tape and mud the seams.

 

[CWYfire]

Thanks BeGreen,

I was thinking there was a variance of the back distance if there is a Durock heat shield installed. I chose to cheat backward to get some distance between the flue and all of the dimensional wood around the header area. That just bothered me to have heat so close to so much wood when I could gain a couple inches so easily.

Plus it allowed the stove to sit back in the alcove where it is almost flush with the outside wall nicely out of the way for summertime furniture rearrangement.

The alcove does flare out from the corner at the back wall forward. However that is the question.

From the back of the stove forward, the distance is less along the sides than what is specified by the manufacture for a typical corner installation.

The measurements are as follows: At the back corner of the stove the nearest distance is 19 ½” at an angle that is perpendicular out from the angular walls toward the stove.

From the same back corner the distance measuring parallel to the back over to the side wall is 20 ½”. At the one foot (1’) mark forward from the back corner of the stove, (which is about the middle of the stove), the distance to the angular sidewalls is 24”, measuring parallel with the back wall. Finally five inches from the front of the stove, which is the mouth of the alcove, the distance from the stove to the side walls reaches the manufacture’s specified minimum of 26”.

Because of being under the minimum for a side wall in a corner install, I figured it would be safer to use the heat shield at least up the sidewalls 6” to a foot above the stove.

Please get back with me after looking at these measurements to see if my thinking is right or if I have created a hazardous condition.

Thanks,
Ed

 

[begreen]

OK, if that is what you've got, then side wall shields will be needed. They should match the rear shield in height. So far nothing sounds hazardous. The combustibles behind the shield will be cool to the touch. An NFPA wall shield is very effective. Remember to have an air space at the bottom as well as at the top. The idea is to allow air to freely circulate from bottom to top behind the wall shield.

 

[CWYfire]

So the side walls must have full wall shields rather than only half wall? Dang... I was hoping to be able to stagger the sides down for visual effect....

OK... I am going to tile the shields. How do you recommend covering the few inches of air space left at the top near the ceiling and at the bottom to the floor? Should I just glue some tile pieces onto the sheetrock that is behind the shields so the grout lines match the tile on the shields?

If so can I do this by just "Back Buttering" those pieces and sliding them into place after I get the shields finished? Or should I glue them in place before I put up the shields?

Would it be OK if I should need to add an extra 1/2" strip behind the side shields, which would create a 1 1/2" airspace, so that the angle matches the sheetrock at the opening of the alcove for a cleaner finished product?

The ceiling will not require a shield CORRECT?

Now for some electric questions.

1. If I am going to place an electric outlet in the alcove for a blower is it best to put it behind the stove or on the side toward the front of the alcove at the farthest distance from the stove?

2. Should I use a metal or plastic electric box?

3. Should it be installed like a sheetrock box with the ears holding it in place being behind the heat shield? What I am asking is will it be code if the electric box is out in the airspace and secured to the shield?

Thanks,
Ed

 

[begreen]

No, the shields only needs to be 37.5" high, though there is no harm making them higher. The bottom of the shield should be 1" off the floor. No need to dress this edge. No one is going to lie on the floor looking up at it. The top edge can be dressed with a cap tile. I'm not a tiler. For tiling ideas it would be better to go to a tiling forum like www.johnbridge.com . It's ok to have 1.5" for the wall shield air space, 1" is the minimum, though I'm not following the reasoning here. Posting a diagram of the design would help.

If the electrical box is kept low and to the side it should be ok. But that question would best be answered by someone that owns this stove and is familiar with how much heat is radiated from the lower back of the stove. I would use a metal box regardless.