new guy here/really did research this question-

[BuoyTen]

Hi all, I searched the forum for a few days looking for an answer so that my first post could possibly not identify me as slacker. It is a fundamental question about a clearance reducing wall, not addressed straightforward in NFPA 211.

I have a new sheetrocked supporting wall, which my stove is being place in front of. I am spacing out a piece of cementboard allowing 1" of open space at top and bottom. The plan was to fasten with 1" lengths of tubing, fastened with screws in 6 locations (3 per side). The cement board is 3'x7' and this will prove to be kind of flimsy.

Is it acceptable to build out the airspace with 2 strips of cement board (an approved method) but fasten them around the edges. Or will this not allow for enough air movement?

 

[Warm_in_NH]

Vertical strip should be fine but full length horizontal runs would restrict the convective air movement that's needed to move the heat away.

 

[BuoyTen]

ok thank you, so yes i will fur the wall out at the edges-

how do we feel about also furring out the one stud that lands in the middle of the wall (directly behind the stove)?

any concern of the fasteners conducting heat to non combust wall?

it sure would take a lot of bounce out of it when i install the thinstone.

 

[coaly]

The heat shield must be off the floor for air to enter at the bottom, and exit at the top. This link shows NO fasteners centered behind the appliance.
https://www.hearth.com/econtent/index.php/articles/stove_wall_clear

The most common spacers are ceramic like fence insulators or spacers made for the application.

 

[begreen]

Using doubled-up, 3" wide, vertical firring strips of cement board like Durock is fine. Just be sure the sheet being supported is 1-3" off the hearth and open at the top to allow good ventilation behind it. I personally wouldn't worry too much about a screw transmitting enough heat to promote pyrolysis in this configuration.