Wall shield install for Defiant in garage

[STJP]

The shield is built one inch off the wall with steel spacers. The space is open at the top and bottom to allow air circulation. The stove is 18 inches from the shield in the rear and 17 inches from the side. The flue DuraVent is rated at 6 inches to combustables so no need for any additional shielding to walls.

I have looked at lots of heat shield installations online. It seems 24 gauge sheet steel is recommended in the one place I can find any sort of "official" mention of gauge. What I used, largely (no pun intended) because of area I wanted to cover. I installed galvanized 29 gauge grade 80 so a pain to bend in the corner. This is not as thick as 24 gauge. Twenty-four gauge to cover the area I covered would have required a special order and would have been difficult for me to transport and install.

I fail to see how modestly thicker metal would have a meaningful difference, but I intend to put a remote thermometer behind the shield to check temp. during a hot fire.

Regarding online pictures I viewed of stove installations ......I am shocked there are not more stucture fires.

STJP

 

[fbelec]

what are your plans for the walls as is or brick/stone. if as is that is going to radiate a ton of heat

 

[STJP]

fbelec,

Its worked really good so far with the stove up to 500 degrees. At that temp., the sheet metal is not warm to the touch. So somewhere south of 98.6. Good convection flow behind the metal. In my 30 x 40 garage with 6.5/12 trussed roof, I'll take all the reflective heat I can get.

Cheers,

STJP

 

[begreen]

NFPA 211 does call for 24ga sheet metal, but what you have is probably fine. Aluminum foil would also work but would be too flimsy to be practical or safe. This may be the intent of the 24ga requirement. That is to have a shield that is sturdy enough to stand up to abuse by stove tools or wood storage near it.

 

[Easy Livin’ 3000]

If you are going to leave the wall open, maybe fill the spaces (between studs) with Roxul? Maybe not, perhaps that would make the studs pryolyze more?

 

[begreen]

No insulation behind the shield. Free convection of air behind it is required. The studs will be fine.

 

[STJP]

No insulation behind the shield. Free convection of air behind it is required. The studs will be fine.

I agree begreen.

ED 3000, not sure what insulation would accomplish. Had stove at 700 degrees last night and heat shield 18 inches away was not warm to the touch. This shield is built to VC specs. and I am pleased with its performance.

STJP

 

[begreen]

Shield temp is not too meaningful. It's the temperature of the combustibles behind the shield that is important.

Question, are wood stoves in a garage permitted in your area? They are not here, but rules vary with location.

 

[Easy Livin’ 3000]

I agree begreen.

ED 3000, not sure what insulation would accomplish. Had stove at 700 degrees last night and heat shield 18 inches away was not warm to the touch. This shield is built to VC specs. and I am pleased with its performance.

STJP

Just a thought.

Does VC spec to use sheet metal thinner than the fire code requirement at 18" away from stove? Interesting if they do.

I suspect it'll be ok, as per BG, and was just throwing an idea out. That said, that thin steel will burn faster than the code requirement thickness. Sheets of aluminum foil would probably be ok under most conditions.

It's your garage and your (insurance company's) risk. You now can't say that you don't know that 29 gauge is thinner than the code requirement. Your insurance company would be interested in this decision. But, they may be understanding, once you explain that the 24 gauge was hard to get and for you to bend.

 

[FTG-05]

If you are going to leave the wall open, maybe fill the spaces (between studs) with Roxul? Maybe not, perhaps that would make the studs pryolyze more?

No insulation behind the shield. Free convection of air behind it is required. The studs will be fine.

It appears you two are talking two different things:

Ed is talking about insulation that is between the studs, not between the studs and the wall shield. Hence, less heat loss to the outside world. The gap between the studs (and the insulation) remains and the shield does what it's supposed to do.

Begreen sounds like he's talking about insulation between the studs and the shield. Not good, as he states, since it destroys the air gap.

That's the way I read it anyway.

 

[Easy Livin’ 3000]

It appears you two are talking two different things:

Ed is talking about insulation that is between the studs, not between the studs and the wall shield. Hence, less heat loss to the outside world. The gap between the studs (and the insulation) remains and the shield does what it's supposed to do.

Begreen sounds like he's talking about insulation between the studs and the shield. Not good, as he states, since it destroys the air gap.

That's the way I read it anyway.

FTG- you are correct, thanks for clarifying. Still might not be the best idea in these specific circumstances, but, I'd do it (Roxul between studs, not between wall and shield.

I might even switch out the wood studs with steel ones with that flimsy sub-code sheilding.

 

[begreen]

Do you mean in the wall behind the plywood? Roxul would be fine there. The heatshield metal is lighter than specced but quite adequate as a heat shield. As long as stuff is not stored behind the shield that bends or distorts it, the shield it's probably ok. There would be little to no gain using metal studs. FWIW, that metal is the same stuff used on our garage and many metal buildings when painted. As long as it is not abused it lasts for many years.

 

[Easy Livin’ 3000]

Do you mean in the wall behind the plywood? Roxul would be fine there. The heatshield metal is lighter than specced but quite adequate as a heat shield. As long as stuff is not stored behind the shield that bends or distorts it, the shield it's probably ok. There would be little to no gain using metal studs. FWIW, that metal is the same stuff used on our garage and many metal buildings when painted. As long as it is not abused it lasts for many years.

I agree, just giving the op a hard time.

When I looked at the pictures at first, I didn't see that the plywood extended all the way down the wall behind the heat shield, thought some Roxul in the stud cavities might be an improvement to open. If it's already enclosed, I'd still considering taking the plywood up to insulate, if I were looking for something to do, particularly if the plywood is screwed not nailed.

Didn't mean to confuse anyone by suggesting that the space between the wall and heat shield be stuffed with anything.