Options/Requirements for wall shield?

[Slow1]

Ok - I'm considering an install that would require a shield on one side for clearance. I know the basic rules (1" air gap, non-combustible materials, open on top and bottom for free flow). What I would like to ask the forum gurus (and others too) is really two things.

1) Does the shield have to go floor to ceiling or just cover the section of the wall to the side of the stove? i.e. if the stove is x feet tall, then does the shield just have to be the same x feet high? Same question to width - how far forward/back up/down does it need to extend? I imagine you can't just match the dimensions of the side of the stove and go stick a piece of sheet metal like a shadow on the wall - or could you (if one were so inclined?).

2) This is the more fun one... Since I am looking at this from the side, I'm looking for ideas/suggestions on how to build one that would look nice (pass the "wife" test with flying colors) as well as be reasonably easy to assemble. Our walls are all painted plaster and to make it more complex, there is a 'chair rail' made of wood that runs along all the walls as the room used to be a small dining room. So what could be used to make this look nice from both the side as well as the front faces with minimal complexity? Really can't expect an industrial look to pass muster here.

Thanks in advance.

 

[begreen]

Good question, I think the shield needs to exceed the stove dimensions by at least 6" in each direction, but will have to look that one up.

As for looks, it would help to see some pictures of the location. The shield doesn't need to be open on the sides, they can be decoratively capped. What's the height of the chair rail? What do you intend to use for the shield material? Cement board with tile, decorative sheet metal or ?

 

[Slow1]

Good question, I think the shield needs to exceed the stove dimensions by at least 6" in each direction, but will have to look that one up.

As for looks, it would help to see some pictures of the location. The shield doesn't need to be open on the sides, they can be decoratively capped. What's the height of the chair rail? What do you intend to use for the shield material? Cement board with tile, decorative sheet metal or ?

Thanks for the reply - I have not made any decisions on the material for the shield and in fact am looking for suggestions. I can dig up a picture when I get home. You can picture a corner of a room with a hardwood floor and 'normal' off-white painted drywall type walls. The hearth is raised 2x4 then tiled but the edges are stained oak to match the floor. I do not wish to have to shield or modify any walls but the one on the right side that needs it, but somehow I suspect that to make the area look decent I'm going to be stuck re-surfacing the whole corner (ug).

I'm open to (and in fact looking for) suggestions. Simple is good - inexpensive and simple may be good for a start then I could perhaps improve in the future... I don't know, I generally would rather do things 'right' the first time though. I don't have a lot of time to devote to this project though so I'm hoping it doesn't get out of hand.

 

[firefighterjake]

I think the shield type really depends on the time and money you want to invest in the project, handyman skills and home decor. In the past here I remember seeing a very sharp looking shield built out of copper . . . but I have no idea of how much that would cost. I'm also partial to the shields and walls built with stones -- real or good fake stuff.

 

[Slow1]

I suppose what I'm looking for is a minimalist option here - functional and at least pleasing enough to look at to not be an eye sore. I'm sure putting up stonework to make the whole corner appear to be stone would look pretty nice, but reality is that a project of that magnitude is beyond me right now.

On the flip side, while stretching sheets of tinfoil off nails 1" from the wall MIGHT technically meet the requirements, I'm quite certain that wouldn't even pass my standards for appearance (or durability).

I wonder if there is a way to do some sort of sheet metal that can somehow blend into the walls (can it be painted to match?) and hung only where needed and how would that really look?

 

[Wood Duck]

I think the shield has to cover any part of the wall that is within the required clearance distance from the stove. Say the clearance requirement is 18 inches from the stove, and the wall is 12 inches away. If you measure the distance from the stove to a point on the wall several inches above stove height, you'll find the distance is longer than 12 inches. At some point on the wall you'll be 18 inches away from the top corner of the stove and that is where the shield can stop. If you want to you can calculate the height on the wall above stove top height (a) if you know the distance from stove to wall (b) and the required clearance (c) using the good old pythagorean theorem: a^2 + b^2 = c^2. For my example that would mean a= unkonwn, b = 12, and c = 18. Put the numbers in the formula and a^2 + 12^2 = 18^2, or a^2 = 18^2 - 12^2 = 324 - 144 = 180. So a = square root of 180 = 13.4, so the shield has to extend 13.4 inches above the stove top height. At least that is how I interpret the requirement.

 

[Slow1]

I think the shield has to cover any part of the wall that is within the required clearance distance form the stove. Say the clearance requirement is 18 inches from the stove, and the wall is 12 inches away. If you measure the distance from the stove to a point on the wall several inches above stove height, you'll find the distance is longer than 12 inches. At some point on the wall you'll be 18 inches away from the top corner of the stove and that is where the shield can stop. If you want to you can calculate the height on the wall above stop top height (a) if you know the distance from stove to wall (b) and the required clearance (c) using the good old pythagorean theorem: a^2 + b^2 = c^2. For my example that would mean a= unkonwn, b = 12, and c = 18. Put the numbers in the formula and a^2 + 12^2 = 18^2, or a^2 = 18^2 - 12^2 = 324 - 144 = 180. So a = square root of 180 = 13.4, so the shield has to extend 13.4 inches above the stove top height. At least that is how I interpret the requirement.

That makes sense to me - I would hope that the inspectors would agree In this case the clearance is 24" required and I'll have about 21.75" to the wall so I expect that would put me adding about 1.1" additional border on the shield (or 2.2" total added to the width and height if centered) as a minimum. Not a huge added size here. Side of the stove is 35.5" x 25" making my minimum shield size about 38"x27.5" if well placed. Wonder how that would look with painted sheet metal, not a huge amount of support required for that small a piece I would think.

 

[firefighterjake]

Here's a couple of wall shields using copper . . .

https://www.hearth.com/talk/threads/copper-as-heat-shield-material.83347/#post-83347

This is the thread I was thinking of that used copper that is normally used in ceilings . . . Offroadaudio's install. I think it may look good or garish depending on the home decor.

https://www.hearth.com/talk/threads/heat-shield-question.29865/#post-29865

 

[Highbeam]

I think that the NFPA chart requires the metal to be 24 gauge or thicker. Most times, the wall shield is not necessary. You say your installation will require a wall shield. What do you hope to accomplish here. The NFPA tables are written for the unlisted devices and give 50 and 66% reductions to the standard 36" requirement. You can't apply the 66% reduction to a manufacturer specified minimum clearance the same way. A few rare stoves specify the use of wall shields in their documents but not many.

Which stove? What are you doing?

 

[Slow1]

I think that the NFPA chart requires the metal to be 24 gauge or thicker. Most times, the wall shield is not necessary. You say your installation will require a wall shield. What do you hope to accomplish here. The NFPA tables are written for the unlisted devices and give 50 and 66% reductions to the standard 36" requirement. You can't apply the 66% reduction to a manufacturer specified minimum clearance the same way. A few rare stoves specify the use of wall shields in their documents but not many.

Which stove? What are you doing?

I'm looking to install the Progress in place of my Fireview. There is a wall to the right of the stove - it is now 24" from the FV, however the PH is 4.5" wider than the FV meaning that if I keep the stove centered on the chimney, the edge of the stove will be 2.25" closer to the wall (or 21.75") the listed clearance is 24" on the side. Adding a wall shield will reduce the clearance requirement (I don't recall the official number, but it is well below the 21.75") according to WS.

As you can see, this is a relatively small amount of variance from the spec, but it is what it is even if annoying to deal with.

 

[begreen]

To keep things simple I would have a sheetmetal shop bend you up a sheet of 24 ga, with a Z leg on the outer, side edge. The Z leg will provide a finished looking vertical side and it will give you an attachment "foot" to screw to the wall. The inside corner edge can be notched to go around the little chair rail molding. Have them also hem (fold over) the top edge for a more finished look. Paint it and install using stand-offs in the middle and at the inside edge end.

If you don't want to have that attachment foot, then just have them bend it in a 1" L on the vertical edge so that it still looks ok from the side and use standoffs to attach to the wall.

 

[fossil]

Do you have the owner's manual for the Progress? I looked at Woodstock's website and it said "coming soon". You might want to give them a call and ask whether or not the Progress manual specifically says that a wall shield may be used to reduce CTC (I know the Fireview manual did have words to that effect)...if it (the Progress manual) doesn't say that, you can't do it.The appliance manufacturer's documentation is the authoritative source of installation information for a tested/certified stove. Rick

 

[Highbeam]

People usually build these wall shields for the wrong reasons. They are not required if you meet the minimum clearance to combustibles, they do not accomplish a clearance reduction unless (rarely) your specific stove specifically allows it in the manual. I have heard of woodstock allowing some reductions and providing written documentation to satisfy the AHJ as well as your insurance company so be sure to get that from them.

 

[Slow1]

Well what do you know... I looked in the manual and indeed it does specify how wide and tall it needs to be. Much larger than I had hoped However at least I know now. Interestingly it is wider than my wall so at least that limits things a bit. It is 98.5" wide by 67.5" high per spec. Yuck. Now to figure out what to make it out of and cover it with etc.

Maybe having the chimney slant a few degrees to make up that 2.25" isn't looking quite as bad anymore.

 

[begreen]

?? Where are you reading this spec? That sounds like shielding for the flue pipe, except for the width.

 

[Highbeam]

Woodstock also has a habit of recommending things that are surely good ideas but are absolutely not required. For example, they seem pretty fond of a sheet of metal being built into the hearth pad when only ember protection is required.

In the manual, does the text clearly state that you will be able to reduce the clearances by a specific amount by using that wall shield?

 

[begreen]

I just found what appears to be an error in their docs. They are saying that for a pipe shield, it's only required for the first 36" above the stove. That's the first time I have heard this. My understanding is that if single-wall pipe is less than 18" from a combustible surface like a wall, it must be shielded per NFPA spec all the way, with no exceptions. What is the exception that Woodstock is listing here?

 

[Slow1]

Woodstock also has a habit of recommending things that are surely good ideas but are absolutely not required. For example, they seem pretty fond of a sheet of metal being built into the hearth pad when only ember protection is required.

In the manual, does the text clearly state that you will be able to reduce the clearances by a specific amount by using that wall shield?

Yes - it states it reduces it down to 12" with the shield in place. I'll have to post the table.

In any case I am trying to figure out now how that slanted pipe will look with a 2.25" offset... can't exactly move the chimney where it leaves the house and I only have about 2' of pipe before the 90* bend to exit so 2.25" over 24" is probably just enough askew to look "wrong" eh?

 

[begreen]

Where did the 98.5" wide by 67.5" high dimension come from? This table?



A typical installation will look more like this, though narrower if it's the sidewall:

 

[Highbeam]

Is this single wall or double wall pipe? The single wall systems can use the variable angle elbows that can be contorted to make the 2.25" offset happen and have a vertical pipe. With double wall it is much harder.

 

[Slow1]

Here is the page from the Progress Manual:

 

[Slow1]

Is this single wall or double wall pipe? The single wall systems can use the variable angle elbows that can be contorted to make the 2.25" offset happen and have a vertical pipe. With double wall it is much harder.

This is black connector (painted blue to match stove) single wall - that sounds like it may be a reasonable and viable option if I can find one of those elbows... Perhaps then I go for the rear vent to have the most 'bending' possible behind the stove eh?

 

[begreen]

Methinks someone at Woodstock has misinterpreted NFPA. I have never seen such an overkilled wallshield. But why the back wall shield for a Progress? You have a Fireview correct and want to protect the sidewall?

Edit, I missed that you are upgrading. Sorry, I shouldn't be bouncing back and forth between threads and activities.

 

[daveswoodhauler]

Saw the photo of the rear wallsheild, and it appears as others have said, overkill.
Have you been able to contact Woodstock regarding the diagram, and perhaps it would not be applicable for a side wall shield? (I've just heard that everyone has such good things to say about Woodstock customer service, so perhaps the diagram is incorrect seeing that the Progress is a pretty recent stove?) Again, just thinking out loud....but its probably at least worth a call/email. Good luck

 

[Slow1]

Methinks someone at Woodstock has misinterpreted NFPA. I have never seen such an overkilled wallshield. But why the Progress doc? You have a Fireview correct?

Umm.. well... you see there are these days when the Fireview just can't quite heat the whole house (it is over 2400 sqft after all) as much as we like and the wife seems to want it even warmer each year... so, being tempted as I was, I found a buyer last year for the FV and, well... you know how it goes