# How to attach metal Lath to Durock Cement board?



## dnichols822 (Oct 9, 2008)

Same question as the subject, I don't know what to use to attach the wire mesh the the cement board so that it stays up.


----------



## fossil (Oct 9, 2008)

Why do you want to do that?  Rick


----------



## Corey (Oct 9, 2008)

I suppose for tile or flat stone, the durock is a good enough substrate to bond directly to.  Maybe you'd want a little more 'tooth' to stick something heavier like real or cultured stone work?

The only way I have seen wire lathe put up is with roofing nails or long staples.  Ideally, you'd shoot them into what ever is supporting the durock.  If there is plywood behind, you should be OK to shoot right into that, but if only studs, you should probably aim for those.


----------



## dnichols822 (Oct 9, 2008)

I need the cement board for a heat barrier.  I am putting cultured stones behind my wood stove on the Durock.


----------



## jrousell (Oct 9, 2008)

I have the same setup
 I used screws and fender washers to attach it- and made sure that the screws went through to wood behind to really hold well..
 then applied scratch coat,  then the   backbuttered the cultured stone and applied...


----------



## begreen (Oct 9, 2008)

You probably already know this, but without a 1" air gap behind the durock, and a 1" opening top and bottom, this is not an NFPA 211 approved heatshield.


----------



## dnichols822 (Oct 9, 2008)

adkdadto4 said:
			
		

> I have the same setup
> I used screws and fender washers to attach it- and made sure that the screws went through to wood behind to really hold well..
> then applied scratch coat,  then the   backbuttered the cultured stone and applied...



That is what I planned on doing unless I heard a better idea.  How thick was your scratch coat and does back butter mean you put more motar on the back of each stone and then pushed it in the scratch coat?  I didn't get good direction on installing this from the place I bought it from.  You say you have screws going into the wall behind the Cement board?  I thought that wasn't good cause the screw will conduct heat through it.  I wouldn't think it would be a "real" problem with all the layers over it, but I don't know if the code will allow it?  If so that is what I am doing!  

And yes, I do have a one inch gap between the board and the wall.   

Thanks for all of the help.


----------



## begreen (Oct 9, 2008)

Good man. It sounds like this is going to be a nice setup. Please take pics and post.


----------



## jrousell (Oct 9, 2008)

I didn't know you were making this for a  heat shield...

 My setup was for facing a zero clearance wood sotve.fireplace  so it is a bit different than yours... i was bridging gaps  across metal of eth stove and plywood and durock.. so I needed a lathe and scratchcoat across them all to ahve a nice uniform substance to adhere to... 

I don't think you even need lathe if you are using durrock -- but you should double check thaht with the cultured stone installation docs they have....

 I would suggets going to the cornign websiter and lokiung at their installation documents for your specific situation.


----------



## Gwleo (Oct 9, 2008)

Air stapler with the appropriate sized staples.  I helped my buddy build his hearth before building mine and learned that the right sized staples is important.  Oh, and use lots and lots of staples!!

(by right size I mean mainly length.  He was shooting 11/2" staples, which was fine until he hit the metal 2x4's.  I put up 2 layers of cement board and 3/4" staples I think.)

I will be posting pictures of my install shortly, if I can figure out the process.


----------



## sullystull (Oct 9, 2008)

Some install instructions say to let the scratch coat dry for 24 hrs.  Did you allow the scratch coat to dry or did you simply apply the stone to the "wet" scratch coat?



			
				adkdadto4 said:
			
		

> I have the same setup
> I used screws and fender washers to attach it- and made sure that the screws went through to wood behind to really hold well..
> then applied scratch coat,  then the   backbuttered the cultured stone and applied...


----------



## G-rott (Oct 9, 2008)

On the last question-Dry, and it's called a scratch coat because after you trowel on the mortar, you scratch it to roughen the surface so it has a lot of tooth, to grab the mortar on the stones.  A scratch comb can be purchased or you can make one with nails in a board or even use a scrap of lath for a one tome application like this.

Did you know lath has a right side up?  The little openings should be facing up.   Wall - ]/  - lath.  Hope this helps, the openings facing up will keep the mud from sliding off the wall.

Garett


----------



## dnichols822 (Oct 9, 2008)

I did not know the lath had a right side.  Thanks that tip.  I'll have to go to corning website and see if I can get some clear instructions.  Thanks.


----------



## Jags (Oct 9, 2008)

D-Nic said:
			
		

> I did not know the lath had a right side.  Thanks that tip.  I'll have to go to corning website and see if I can get some clear instructions.  Thanks.



The "right side up" is really only important if you are applying the lath to wood.  The "sharp" or "right side up" was designed so that it would bite into the wood creating a "positive" connection to the wood everywhere.  There are also brands of lath that do not have this "sharp" side. 

That is, of course, assuming that I am talking about the same "right side up" that you guys are.  Maybe your talking about something different?


----------



## TinasArk (Nov 10, 2008)

Oh you guys always pull through...this is just the question and answers I was looking for!
Thanks All,
Tina


----------



## wellbuilt home (Nov 10, 2008)

No need for  wire over the DR  just nail the DR on to 1" strips of wood or use steel hat track. Then use a mix of 3 parts port land cement 2 parts grey thin set 7 parts sand . Wet the stone and the wall ,splugee some mix on the wall and let it set up a bit,    then butter some splugee on the stone . (Don'T be cheep but don't make a mess on the stone)  We like to dry lay the stone on a board ,use a grinder to cut them in tight. get some colored cement to cover the edges of the stone when you cut them. buy about 20% extra stone . Afire place only take 3 or 4 boxes of stone  but some times the boxes don't have all the different sizes in just 4 boxes . Don't breath the stone dust . We grind out side and bring in 3/4 ply wood boards that fit thru the door 2x the with of the hearth . Try to keep the stone level . Snap some lines on the wall and board to stay straight  Mix about 3 gallons of splugee at a time . don't add water to the mix ,it makes it week. If you are filling the joints use a squeeze bag. hope this helps  .John


----------



## Hogwildz (Nov 10, 2008)

Corning's installation instructions say lath on everything but bare masonry surface.
Even cement board must have metal lath.


----------



## Jags (Nov 10, 2008)

Hogwildz said:
			
		

> Corning's installation instructions say lath on everything but bare masonry surface.
> Even cement board must have metal lath.



Also, Pro Line and Coronado suggest this.


----------



## wellbuilt home (Nov 11, 2008)

Ive never used that material , but  have installed miles of stone over the past 30 years . You don't really have any trouble with stone work if its inside  and is not subjected to the freeze thaw cycle. But  I'm just speaking from 30 years of experience I haven't read any directions since the late 70s  sorry guys. I stand corrected


----------



## Jags (Nov 11, 2008)

wellbuilt home said:
			
		

> Ive never used that material , but  have installed miles of stone over the past 30 years . You don't really have any trouble with stone work if its inside  and is not subjected to the freeze thaw cycle. But  I'm just speaking from 30 years of experience I haven't read any directions since the late 70s  sorry guys. I stand corrected



Apology accepted  

I think they (mfg.) has to spec it that way because this stone is EXTERIOR rated, and if used in such an environment, they have to have their collective butts covered.


----------

