Need Help, Heat Shield/ failed Wett inspection regulations

[Mr. B]

Hello all I have a question regarding my heat shield. I’m in Nova Scotia, I have just recently installed a new Drolet stove and subsequently failed a Wett inspection. My installation for both the stove, the chimney, the hearth pad, the heat shield, etc, were all to the “T” perfect according to the inspector with only one exception. He failed me due to the materials of my DIY heat shield, specifically the cement board. All dimensions, spacing, etc, for the shield was perfect. I made my heat shield out of 1/2" Durock Cement Board and skim coated the surface with 1/4" of mortar. (My wife and I didn't like the look of a tiled heat shield). So nothing in my heatshield is "combustible", the Cement Board is advertised at Home Depot for use as a heatshield (I know this means very little), it is Non-Combustible according to everything I can find on the internet, and the masonry coat on top is certainly not combustible.

His reasoning cited somewhere in the B356-17 building codes that since it was a "built on site" heatshield, I can't use cement board because if the house was on fire, the cement board would eventually crumble. Yes.. the absurdity. He agreed with me, that it doesn't make any sense that if your house is already on fire (caused by some other means) to such a large degree that your heatshield crumbles, well its as non-issue. Additionally in further sillyness, if I was to add tiles to the front of my cement board, (on top of my 1/4" skim coat) then my heat shield would pass inspection. Regardless of the same logic, that a pre-existing house fire would still crumble my cement board heat shield "with tiles"...arghh

My stove manufacturer states that I can reduce my clearances with a heatshield constructed of "ceramic tiles, or equivalent non-combustible material, on non-combustible board spaced out at least 1" by non-combustible spacers". I would like to think that a 1/4" skim coat of mortar can be considered equivalently non-combustible material, on-top of cement board. If so, I would be complying with the manufacturers rules which should supersede anything else.

Anyway, I would appreciate any of your thoughts on the matter. Do I have any recourse to get a second opinion on this or to contest this? Has anyone ever contested a Wett inspection? I need one for my insurance so I am a little stuck and really don't want to pointlessly tile over this heatshield. Thanks in advance.

 

[charger4406]

If my house was burning to the extent to destroy the duroc board,
I believe the heat from the stove would be the last thing I would worry about
It may have passed if you had tiled the shield, still do not see the logic.
You may have to get the drolet heat shield for your stove and double wall pipe
to satisfy your inspector.

 

[charger4406]

Where your spacers for the heat shield non combustible also?

 

[Squirrel]

From the Durock specification sheet ,
13. USG Durock® cement board panels should not be used in areas where they are exposed to temperatures that exceed 200°F.

 

[charger4406]

If you do not like the look of tile or stone, you could hang a sheet of painted metal,
a friend of mine had done this and it turned out nice.
you could also use two 45 degree elbows to move the stove out from the wall,
if you don"t mind loosing a foot of floor space.

 

[begreen]

First time I have heard this one... If this is the inspector's field judgment, then you have the right to request documentation to substantiate this concern and/or another opinion. Have them provide the testing that shows the cement board would crumble before the house was reduced to ashes. If that fails then a metal sheet attached that extends 6" above the flue collar and is painted to match the mortar coating may have to suffice.

 

[begreen]

From the Durock specification sheet ,
13. USG Durock® cement board panels should not be used in areas where they are exposed to temperatures that exceed 200°F.

And this application is well within those parameters. USG does not say to not use this product if you expect the house to catch on fire and it should be the last item standing.

 

[EbS-P]

Well there options. Fight it, pull it down and replace with????metal?? or tile it. I would just just tile it for now with something like this. Vertically. Cheap, fits the look. And you could pass inspection ASAP.

I wonder how the skim coat would handle the thermal cycles? Just my two cents.

Evan

Cityscape Gray 12-in x 24-in Glazed Porcelain Cement Look Floor and Wall Tile https://www.lowes.com/pd/American-V...in-Cement-Look-Floor-and-Wall-Tile/1002619464

 

[electrathon]

You could get sheet metal and cover the cement board. After the inspection you can then pull it back off.

 

[Mr. B]

My heat shield is made on two metal studs used as spacers, built with proper distances from the floor/ceiling/centerline. Thanks all for your replies. Very much appreciated and great insights. Today I had a similar revelation to Charger4406. Luckily I built my hearth pad so its currently 22" away from the stove front. I believe I can use two flue 45's and move the stove out exactly 4 inches, bringing me to an 18" hearth pad in the front, giving me my 7.5" I need from combustibles in the rear, and then pass inspection. (Then probably revert back to the current set-up..). The only things that sucks about this plan is the expensive double wall elbows ill have to buy to make it happen... I'm contemplating keeping them in my back pocket and see if a new inspector even minds the heat shield, if so, I can literally add the elbows into the flue in a matter of minutes. Then hopefully satisfy them.
Currently the heatshield is barely warm to the touch after hours of decent burning...
Again thanks all for the thoughts and info, great community here.