# Looking for advice - Stacked stone fireplace surround



## TSHERV (Feb 28, 2019)

Hi,

I have a 20 year old home and have decided to replace the outdated tile around my gas fireplace (corner fireplace).  The tile was outdated so I decided to go with a stacked stone design.  This is the stone I've decided to use:

https://www.menards.com/main/buildi...2-c-19691.htm?tid=-6303989779778476630&ipos=2

I've tore off the tile and removed most of the drywall around the fireplace.  I'm planning on using 1/2" durock with a vapor barrier behind it.  I've run into a couple roadblocks though and am looking for advice.  I've attached a "before" picture and a picture of where I'm currently at. 

Here's my issue:  I was planning on tearing out the drywall all the way to the wall corners and mount durock. Once I tore into it, I realized that there are no studs on the corner.  I stopped removing drywall where its still connected to the last stud. 

Where do I go from here?  Can I use a combination of durock and drywall?  The strip of drywall remaining on each side is about 4.5".  Do I need to remove all of the drywall? I'm planning on running the stack stone all the way to the corners.  If I used a combination, I'd have about 12" of durock and 3.5" of drywall on each side.  Would this work?  If I can use a combination, what do I use for the joints? 

Thanks!


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## Hogwildz (Mar 1, 2019)

You can remove the strips of drywall and install corner studs while you have it open. Or, you can leave the drywall and butt the durok up to it, but you will have to install 30lb or two layers of 15lb tarpaper or other moisture barrier over the drwall, then metal lath over the drywall area. If you run the lath a few inches onto the durok, that should solve any joint issue.

Are you sure there is no studs in the corners? They should ahve put something there to fasten at the angle change in the drywall.


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## WinterinWI (Mar 1, 2019)

I would cut it back as far as you want to go. If there's no stud at the end, just put one in. 2x4s are cheap.


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## TSHERV (Mar 1, 2019)

Thanks for the response.  I can reach my hand in on the inside, and feel the inside angle of the drywall, but no stud.  I thought about adding a stud, but being I just removed part of the drywall, I have no access to a header to attach a stud.  

One other option I thought of: if you look at the 2 drywall strips on each side, there is partial stud showing.  There are actually 2 studs nailed together in that spot (half of a stud showing in the picture, 1 1/2 studs still covered by drywall).  I could add a 3rd stud and join it to the other 2.  That would leave roughly 1.5" strip of drywall on each side. 

Being I don't think I can add a stud on the edges (no header), will I still need to use metal lath if I get the drywall strip down to 1" to 1.5"?  

Thanks!


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## WinterinWI (Mar 1, 2019)

Sounds like the distance from the end of the last stud to the corner is 3"? I would cut the drywall out to the corner, and screw 2 studs that are the height of the opening to the existing studs. That should take it right to the corner and give you support for the edge of the durock. Odd that there are no studs on the ends of the drywall in that corner.


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## TSHERV (Mar 1, 2019)

I'd say that it's about 3" to the corner from the last stud.  It may not be exact, but it's close.

One more question:  I bought tape of thin set for the cement board joints.  Do I need to tape the corners where cement board meets drywall?  If so, what do I use for product (tape / mud)?

Thank you!


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## TSHERV (Mar 1, 2019)

Ok...Here's the update:  I cut away the rest of the drywall and took a picture of the corner without a stud.  I'm looking for a recommendation on what to do with the corner.  The cement board edge will rest on the studs from the opposite wall, but with the angle, I don't think I can screw the board into the studs.  Any thoughts?

Also, what do I need to do with the drywall to cement board joint?  The seam will be covered by stone with a miter cut.  Do I need to somehow tape and mud it?  If so, what do I use?

Thanks.


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## TSHERV (Mar 1, 2019)

One more question: how close to the gas fireplace should I install the plastic vapor barrier?  Is there risk of melting by getting it too close?


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## Hogwildz (Mar 1, 2019)

TSHERV said:


> I'd say that it's about 3" to the corner from the last stud.  It may not be exact, but it's close.
> 
> One more question:  I bought tape of thin set for the cement board joints.  Do I need to tape the corners where cement board meets drywall?  If so, what do I use for product (tape / mud)?
> 
> Thank you!


No, you won't need to tape the corners where the cement board meets the drywall. You will be installing the stone but against the drywall, so the joint will not be visible. You can run a bead of caulk along that seam line if you wish. Are you going to butt the ends of the veneer to the drywall or cut the veneer on an angle so it sits flush against the drywall?


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## Hogwildz (Mar 1, 2019)

TSHERV said:


> Ok...Here's the update:  I cut away the rest of the drywall and took a picture of the corner without a stud.  I'm looking for a recommendation on what to do with the corner.  The cement board edge will rest on the studs from the opposite wall, but with the angle, I don't think I can screw the board into the studs.  Any thoughts?
> 
> Also, what do I need to do with the drywall to cement board joint?  The seam will be covered by stone with a miter cut.  Do I need to somehow tape and mud it?  If so, what do I use?
> 
> ...


So there is wood in the corner. Take a stud, cut a 45 degree angle or whatever will bring it parallel the other studs on the fireplace wall, nail or screw the new corner studs in, and you have a stud to fasten the ends of the cement board to.


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## Hogwildz (Mar 1, 2019)

TSHERV said:


> One more question: how close to the gas fireplace should I install the plastic vapor barrier?  Is there risk of melting by getting it too close?


Is this an out side wall? Is there insulation behind the fireplace unit and in the wall? Are you sure you need a vapor barrier? If it is a corner install, then chances are you the vapor barrier is in the main walls already.


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## TSHERV (Mar 1, 2019)

Hogwildz said:


> Is this an out side wall? Is there insulation behind the fireplace unit and in the wall? Are you sure you need a vapor barrier? If it is a corner install, then chances are you the vapor barrier is in the main walls already.



This is an interior wall.  There is vapor barrier on the exterior wall behind the fireplace.  There was vapor barrier behind the drywall I removed though...


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## Hogwildz (Mar 2, 2019)

TSHERV said:


> This is an interior wall.  There is vapor barrier on the exterior wall behind the fireplace.  There was vapor barrier behind the drywall I removed though...


If there is vapor barrier in the exterior walls, no need for vapor barrier on the fireplace wall. Let it breathe.


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## TSHERV (Mar 2, 2019)

First of all, thank you very much for the great information.  You guys have been a huge help!

I ran into one more potential issue:  When I install cement board, I'm going to have an issue above the fireplace.  What am I going to fasten the cement board to on top of the fireplace?  It looks like there is a "lip" on the top of the fire place where wall material could rest, but it's not flush with the framing around the fireplace.  I'm assuming I can't install a horizontal stud  on top of the fireplace because of heat?  Any recommendations?

Thanks.


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## WinterinWI (Mar 2, 2019)

Do you happen to have the manual for the fireplace? It would have clearances listed.


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## TSHERV (Mar 2, 2019)

I found the manual.  It looks like I need 3.5" on top of the fireplace, which is about what I have.  Can the bottom of the cement board just be loose against the fireplace?  My concern is the top lip of the fireplace isn't quite flush with the studs (lip sticks out a bit).

Thank you!


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## TSHERV (Mar 2, 2019)

Hogwildz said:


> If there is vapor barrier in the exterior walls, no need for vapor barrier on the fireplace wall. Let it breathe.


Just to clarify, it is an interior wall.  If I don't need vapor barrier, I can just go concrete board right on studs, correct?  I don't need any felt, etc.


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## johneh (Mar 2, 2019)

You got it !


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## Hogwildz (Mar 2, 2019)

TSHERV said:


> Just to clarify, it is an interior wall.  If I don't need vapor barrier, I can just go concrete board right on studs, correct?  I don't need any felt, etc.


Yes, cement board to studs. Are you stopping under mantle, or running all the way up to the ceiling?


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## Hogwildz (Mar 2, 2019)

TSHERV said:


> I found the manual.  It looks like I need 3.5" on top of the fireplace, which is about what I have.  Can the bottom of the cement board just be loose against the fireplace?  My concern is the top lip of the fireplace isn't quite flush with the studs (lip sticks out a bit).
> 
> Thank you!


You could install a metal stud in the space across the top of the fireplace, then fasten the cement board to it. Problem solved.
Make sure the manual is not saying you need the gap left open 3.5 above the fireplace. They may want it open for heated air to convect out of.


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## Hogwildz (Mar 2, 2019)

What are the two angled triangular metal pcs on top right & left? What model is this fireplace?


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## TSHERV (Mar 2, 2019)

The fireplace is a Heat & Glo 6000 DVTFL.  I believe the two triangle pieces on top to create space to make sure you keep the 3.5" gap.  That's my assumption.  

I am only installing the stone up to the mantle.  I have 2 concerns at this point:

1)  There are a lack of headers right below the mantle to attach the concrete board.  I should be able to add headers.

2)  What to do with the gap between the top of the fireplace and the header (circled area in the picture).  I don't think I can add any type of material because of the metal triangles at the top of fireplace.

Am I on the right track by adding headers?  

Any advice on what to do above the fireplace (circled area)?

Thanks so much for your help!


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## TSHERV (Mar 2, 2019)

Hogwildz said:


> You could install a metal stud in the space across the top of the fireplace, then fasten the cement board to it. Problem solved.
> Make sure the manual is not saying you need the gap left open 3.5 above the fireplace. They may want it open for heated air to convect out of.



My manual says: 
Minimum Clearances from the Fireplace to Combustible Materials is 3.5" from the top of the fireplace.  Maybe a steal stud would work?


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## TSHERV (Mar 2, 2019)

I noticed that my lumberyard has "non-combustible wood 2x4's".  You something like that work in this situation?  Could I build the header down by adding a 2x4 between the metal triangles on top of the fireplace?


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## Hogwildz (Mar 3, 2019)

Per your manual, they are showing no added header, just finished wall spanning from the headers in place to the top of the unit/surround. I think you will be fine just spanning the cement board and fastening to what is there. Once the stone is in place, it looks like the stone may just catch part of the surround lip to rest on top of. I doubt it will go anywhere with the stone in place. If you really want to add another header, use steel studding. You may have to notch the steel stud around the stand offs on top.

The more I look at your last photo, it looks like you may be able to screw the cement board into the top flange of the fireplace there.
Make sure you use cement board screws and not drywall or just any screws.
You can screw the cement board to what is there, I see no need to add more below the mantle.


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## TSHERV (Mar 4, 2019)

Thanks so much for your help!  I ended up fastening the cement board to the top flange.  All cement board is now mounted and ready for tape and mud.  Thanks again!


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## Highbeam (Mar 4, 2019)

TSHERV said:


> Thanks so much for your help!  I ended up fastening the cement board to the top flange.  All cement board is now mounted and ready for tape and mud.  Thanks again!
> 
> View attachment 241875



That's a lot of screws and they look like drywall screws. You did use the fancy durock screws didn't you?


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## TSHERV (Mar 4, 2019)

Is it too many screws?  They are not drywall screws.  I did use "Cement fiber board screws".  They have a type of green coating on them.  I read somewhere that you want to put a screw every 8".  Maybe I went overboard!


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## Highbeam (Mar 5, 2019)

TSHERV said:


> Is it too many screws?  They are not drywall screws.  I did use "Cement fiber board screws".  They have a type of green coating on them.  I read somewhere that you want to put a screw every 8".  Maybe I went overboard!



8" spacing and the proper screws sounds good. There are durock screws and then there are fiber board screws, I think Hardi is the brand for fiberboard. You used the wrong ones but it might be okay. Any experts know if it's fine? 

Way easier to replace them now!


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## TSHERV (Mar 5, 2019)

These are the screws I used:

https://www.homedepot.com/p/Pro-Twi...ent-Board-Screw-1-lb-Pack-NFCBS1141/301548283


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## Highbeam (Mar 5, 2019)

TSHERV said:


> These are the screws I used:
> 
> https://www.homedepot.com/p/Pro-Twi...ent-Board-Screw-1-lb-Pack-NFCBS1141/301548283



This stuff here is fiber cement board, I like it more than durok.


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## TSHERV (Mar 5, 2019)

Does that mean I used the wrong screws?  Should I replace them?


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## Highbeam (Mar 6, 2019)

TSHERV said:


> Does that mean I used the wrong screws?  Should I replace them?



Bumping your post and question.

They sell two screw products on the same shelf at the depot. One for hardi and one for durock. You used the hardi screws on durock. Does anybody know if that matters?


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## firefighterjake (Mar 6, 2019)

I am far from being an expert, but with your description of the green color and the link mentioning the corrosion resistance of these screws I suspect you'll be fine. Now if you had used regular sheetrock screws without any corrosion resistance I suspect there would be more of a concern . . . at least over time.


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## Hogwildz (Apr 19, 2019)

Plenty of screws, no issue. The screws will be fine. They will outlast you.
I would however, install a screw between the ones you have into the top flange of the fireplace, to assure a sold mount when the metal expands & contracts.


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