1/2 cementboard and tile with 1" airspace

[Bub381]

This is on the walls surrounding my stove which i had prof installed by a cert and lic installer to be safe. The wall beside the stove which is this described protected wall is 225 on the tile and the painted wall behind this barrier is 130.All other tiled surfaces around this stove are around 130 or so.The stove is in a corner and the back corner is 11 1/2" from barrier and the front corner is 12" .This was when the stove was running at 550 and it's a spot about level with the top of the stove..It was a small space about 1' by 1'.It cooled considerably out around that area.Safe?

 

[fossil]

Based on your description, it sounds OK to me. It's also a really good demonstration of what that 1" air space provides in terms of thermal protection for the combustible wall behind the shield...nearly a 100°F drop in temp. Rick

 

[Bub381]

Ya the installer said it was extra protection.I really like the idea of moving air in there plus i have 2 fans on floor blowing into stoveroom.Just making sure.Thanks

 

[begreen]

Is the 1" airspace open at the top and bottom so that air easily convects behind the protective panel?

 

[ditchrider]

On my first install, I screwed a scrap sheet of 1/4 inch hardi backer on top of 1x2 lathe behind my stove (the sheet was about 3'x3'), thus creating a 3/4 inch airspace behind the hardi. It was open on the top and at the bottom for air flow. I knew the stove install was temporary. My thought behind it was reducing the painted surface temp, which was 150 and very hot to the touch. I didn't think the heat was very healthy for the paint on the wall. With the hardi on the wall I couldn't estimate the temp after installing the hardi, but the painted wall temp above the spot where I put the hardi dropped about 20-30 degrees.

I installed the hardi making sure the bottom of the sheet hung near the bottom of the stove, where the coolest air would be to draw up through the air space.

Now that I have relocated my stove, I'm planning the same protection, and hoping to apply stone to the hardi somehow, and also mount the mantel stone that once sat on top of my fireplace hearth in the very beginning.

Based on my experience with this, I think you have a good idea.

 

[KodiakII]

I went a step further on my install, I put sheet metal behind the cement board and used screws that wouldn't go from the cement board to the wall behind the spacers. IE. the spacers (steel furring chanel) are fastened to the wall, then the cement board and sheet metal are fastened to the spacers.

 

[begreen]

On my first install, I screwed a scrap sheet of 1/4 inch hardi backer on top of 1x2 lathe behind my stove (the sheet was about 3'x3'), thus creating a 3/4 inch airspace behind the hardi. It was open on the top and at the bottom for air flow. I knew the stove install was temporary. My thought behind it was reducing the painted surface temp, which was 150 and very hot to the touch. I didn't think the heat was very healthy for the paint on the wall. With the hardi on the wall I couldn't estimate the temp after installing the hardi, but the painted wall temp above the spot where I put the hardi dropped about 20-30 degrees.

I installed the hardi making sure the bottom of the sheet hung near the bottom of the stove, where the coolest air would be to draw up through the air space.

Now that I have relocated my stove, I'm planning the same protection, and hoping to apply stone to the hardi somehow, and also mount the mantel stone that once sat on top of my fireplace hearth in the very beginning.

Based on my experience with this, I think you have a good idea.

Regular lath is combustible, which disqualifies it as shim stock for an NFPA 211 wall shield. Next time used something non-combustible, like long 3" wide strips of cement board, stacked to create the 1" shim.

 

[ditchrider]

Regular lath is combustible, which disqualifies it as shim stock for an NFPA 211 wall shield. Next time used something non-combustible, like long 3" wide strips of cement board, stacked to create the 1" shim.

I thought of that, somewhat... I screwed the lathe 48" apart. Each piece was not directly behind the stove, but to the outside of the dimensions of the stove.

 

[Bub381]

Yes,it is open 1" at the top,bottom and front edge.

 

[Seasoned Oak]

Yes,it is open 1" at the top,bottom and front edge.

This creates great thermal air circulation, it highly unlikely your wall will ever get too hot with this kind of setup. Bare Walls can get pretty hot behind a stove especially if they are well insulated.