wall protection

[loneeagle15]

This is ia follow up to my wall is hot post earlier I am looking to add wall protection and elk mentioned 1 inch of air space if I go this route should it be dead air or would it be better to have a gap on the bottom and top for circulation or should I just use just use a few layers of cement board?
Thanks you guys are always a wealth of info

 

[begreen]

One layer spaced an inch from the wall is sufficient. Include an air gap at the top and bottom (at least an inch) to allow cooler air to convect behind the cement board. Durock's website has good instructions on how to build the protective wall. USG Submittal Sheet 10310.

(broken link removed to http://tinyurl.com/nmmt3)

 

[Gooserider]

This is ia follow up to my wall is hot post earlier I am looking to add wall protection and elk mentioned 1 inch of air space if I go this route should it be dead air or would it be better to have a gap on the bottom and top for circulation or should I just use just use a few layers of cement board?
Thanks you guys are always a wealth of info

Specs on the wall protection REQUIRE the airspace to be open on the top and bottom, however they do reccomend screening the opennings to keep crap from falling behind the protective wall. Best practice is to use inch long non combustible insulators (ceramics are good, but can be as simple as chunks of pipe...) with screws securing them to the walls, but many people have been known to use strips of cement board - Cut 1-2" wide strips and fasten them to the studs, then screw the cement board to the wall, going through the strips into the studs. Some folks have suggested that pre-drilling the holes is helpful, especially if using narrower strips, in preventing the strips from cracking apart. You can then cover the cement board w/ your choice of non-combustible treatments.

Gooserider

 

[elkimmeg]

the other part of reduce clearance protection is care has to be used in attaching it with screws I don't have the code book open but no screws can be directly behind the stove

No reduction can be reduced more than 12" and still remember the single wall pipe clearances still have to be addressed

 

[webbie]

Let me add to or clarify a few points......

The minimum clearance to the ORIGINAL COMBUSTIBLE WALL is shown in NFPA as being 12". This is for "generic" stoves - if your manual and stove label shows otherwise, you can follow the manual.

The 12" is usually measured from the edge of the top plate of the stove to the original sheet rock. This means if you install 1/2" Durock 1" from the wall, the stove could be 10 1/2" from the face of the Durock. This gets confusing because when people use a brick wall it can be almost 5 inches thick with air space. Thus, the stove can be 7" from the brick.

The reduction is given as 66% or 2/3 from - with a 12" minimum. Meaning if original was 30" (on stove label), you cannot go to 10" (unless stove label says so), but have to stay with the 12" minimum.

I have seen various diagrams and answers to the ventilation question - my advice is to leave as much open as possible if you have a large radiant (no rear heat shield or double wall shield) stove. It is easy to leave the entire top open in many cases, and even the entire bottom.

 

[begreen]

JD what stove is this for? Will you be using single wall or double wall pipe coming out from the stove?

 

[loneeagle15]

the stove is a Mansfield and i used double wall stove pipe the manual states 18" to a side wall i went 22"
Thanks to all who replied i feel i will build a wall with a 1" air gap 1/2" cement board and cultured stone which should still give me 18" to the stone and still 22" to my combustible wall again thanks to all