Stone veneer installation - Masons?

Had the lovely pleasure of meeting Lotusseven7 a few days ago when I went to pick up my stone veneer for the fireplace.  The fireplace is currently fully skinned with hardie backer.

I've been getting conflicting info on how to apply it.  Lotus7's advice is sound - mesh lath and scratch, then mud the stone on.  The stone yard's advice was basically "whatever you decide," assuming I was a pro and knew what I was doing.  In their defense, they are a huge manufacturing facility selling large quantities of stone all over North America, not a mom and pop building materials store with time to hold my amateur hand.  So my plan of attack was to watch all the youtube videos and then ask real people for advice.

I narrowed my youtube advice to real stone since that's what I have, not an engineered stone with it's own proprietary methods.  I also limited it to industry-type training/how-to videos and not just anyone with a camera and a youtube channel.  Presented by Sakrete or Rapid Set?  check.  Jimbo's weekend project?  Nope.

All of the videos I watched seem to fall into three techniques:  
1- Mud the veneer and slap it directly on the backer.
2- Scratch coat directly on the backer, then mud and install
3- Absolute MUST use mesh lath and a 3/4" scratch coat or everyone dies.

One of them in category 1 even showed a test piece that the guy tried to rip it off with a pry bar and it just ripped the backer to shreds.  One of them in category 2 showed using regular thinset for large format tile for the scratch coat, and then he put pretty large river rocks on with the same mud.  Most of the ones in category 3 used Type N or S for the whole job.

I think I'm more confused now than I was when I started.  The veneer I'm using is a fieldstone that ranges in height from 1" to 5" and 1.25" to 1.5" thickness.  Any tips or resources?  I'm not discounting maybe just hiring a mason, but I have no idea how to find one I would trust.  Lots of shady contractors round these parts.

Good evening sir, GREAT to get to meet both of you the other day. Thanks for stopping by. Tomorrow I will be doing the veneer on the front of the pizza oven. It is Hardie Backer Board with expanded metal lath screwed on. I will be doing a scratch coat, letting it dry and then applying the stone to it. Whether you choose to do it, the "glue/mortar" can be purchased in the big box stores or at any local masonary supply. Just ask for veneer mortar, it's basically Type S with additional bonding agents. Lowe's sells 2 different ones that will work. I will say that anything that I know about applying the veneered fieldstone I learned from watching masons here at the house. I'm just copying exactly what they did, how they did it and with what materials they used. I'm not really happy having to go through the additional steps IF applying it directly to the stone works, but I don't want everyone to die either!

Good Luck and have fun with the fireplace masonary work. 
 

FYI, I've been trying to find a local mason to do brick work on 3 sides of the pizza oven. A total of less than 27 square feet. Nobody is available until spring! It looks like I'm doing it myself. 

I've had good luck using good tile mortar, which i bet is very similar to veneer mortar.  I did my chimney in the bedroom with stone veneer over the brick and i had a ton of thin set left from a tile job so i used it and it's not showing any sign of going anywhere 

Ok, so I showed this to my dad who has much more masonry experience than me and he says:

Any of the 3 methods will work but option 3 is pretty ridiculous. Lath is always good and you don't need to go crazy on the scratch coat, 1/4 to 3/8 is fine. 

Depending on how you are stacking it, he recommends furrowing the mortar bed if you are leaving some joints ala' brick. If you are doing the drystack look with no or limited joints you don't have to furrow.

Wet down the scratch coat as you go and Type S is a good mortar for this. Be as clean as you can because that style will be annoying to clean. Also make sure the stone is dry, the cement is hydroscopic and it will suck water out of the stone, weaken the mortar and you won't be able to stack much at a time as it will slump down.

Good info above. I have a friend that actually has a business of cutting reclaimed bricks into corners and faces for veneer work. I'll ask him if there are any tricks.

Here is his site, his showroom is a block from my shop.

https://skinnybrik.com/

I have a big bag of this that I got to lay three slate tiles for the hearth, so out of a 50lb bag I have 49 lbs left over.  Will this make a decent scratch coat?  Will it work for the veneer too, or should I just get some type S?

lotusseven7 (Forum Supporter) said:

 

FYI, I've been trying to find a local mason to do brick work on 3 sides of the pizza oven. A total of less than 27 square feet. Nobody is available until spring! It looks like I'm doing it myself. 

 

If I can do this, you most definitely can!

If anyone here can do it, you can!

Backer board has thousands of microscopic "attachment points" per square inch for the mortar to fix to. Schluter's orange board has thousands of small fibers sticking out per square inch.   I don't use Schulter behind big stone walls  though, probably just because I'm old fashioned.  Still use concrete board, seems more robust.

Occasionally, just as overkill, I mark the studs, and every few rows I attached a metal "brick tab" in between a stack.  Probably not needed, but it makes me feel better.

Kind of you to say.  I might do some brick retainers, but I'm hoping to do a dry stack so it might not be any help.  I'm planning a dry stack, but knowing how random these stones are, I'm sure I'll have a few mortar joints to fill.

I've decided to just do some test pieces.  I can understand the lath for wood sheathing, or with exterior installations over vapor barrier like tar paper since it wouldn't have anything to grip to.

I'll try the first two methods; A) just back-butter a stone and smack it on to a scrap of backer, and B) doing a scratch coat on a scrap and do the same back-butter technique on the cured scratch.  If they both fail, I know I gotta lath.

Thanks for testing it!  I have a similar project coming up in the next year or so, so I'm interested.  

So, I began the pizza oven exterior covering and used option #3. Hardie backer board, lath, scratch coat and then the veneered fieldstone and cut bricks. Worked fine for me, but it's obviously an exterior application with LOTS of wind.

Looks AWESOME.  I'd eat pizza from that oven.

Any update?

None.  Holidays, broken truck, hunting season.... totally overwhelmed right now.  Soon.

In reply to Curtis73 (Forum Supporter) :

Is your stone a veneer cut with a flat back?

The easiest way is to avoid the wire lathe and cement it directly to the backer board. Use a toothed trowel like laying tile. 
 

I did a fireplace at my cabin with a very similar looking stone. I stacked it neatly so the joints were pretty tight, and did not grout between the stone. It worked terrific!

If you have gaps as you are stacking it, you can temporarily keep the stone from falling off and sliding down the wall by screwing long drywall screws into the grout joints to rest the stone on until the mortar sets up. 

It is cut with a flat back.  Is that enough mud to hold it?  These are 1.25-1.5" thick and none too light.

In reply to Curtis73 (Forum Supporter) :

Do you see the stone on that wall?  Yes it's actual stone, some granite, bricks, etc. some 60-80 pounds as much as 8 inches deep.  I put that up on the wall over 20 years ago. Just mortar and Brick ties.  In the summer the temps get well over 100 and during the winter as low as 40 below. Examine it carefully,  there isn't a single crack anyplace. No loose stones rocks or bricks.  Just have them damp when you put the mortar on. 
Since they are exposed to rain, sleet, hail, and snow I made sure all the surfaces sloped away from the wall so water wouldn't pool.  

Curtis73 (Forum Supporter) said:

It is cut with a flat back.  Is that enough mud to hold it?  These are 1.25-1.5" thick and none too light.

Enough mud??  That depends on what toothed trowel you use. 
 

A 1/2"x1/2"x1/2" square tooth trowel puts a lot of mud on the surface. 
 

Just butter the backs if you are not comfortable. 

frenchyd said:

In reply to Curtis73 (Forum Supporter) :

Do you see the stone on that wall?  Yes it's actual stone, some granite, bricks, etc. some 60-80 pounds as much as 8 inches deep.  I put that up on the wall over 20 years ago. Just mortar and Brick ties.  In the summer the temps get well over 100 and during the winter as low as 40 below. Examine it carefully,  there isn't a single crack anyplace. No loose stones rocks or bricks.  Just have them damp when you put the mortar on. 
Since they are exposed to rain, sleet, hail, and snow I made sure all the surfaces sloped away from the wall so water wouldn't pool.  

That's really good looking, can you share some more pics - or even make a new thread with lots of pics?

In reply to m4ff3w :

He's got a post around here somewhere with a lot of photos. After talking about it for years we finally got to see it. It's wild. True labor of love. 

SVreX (Forum Supporter) said:

Curtis73 (Forum Supporter) said:

It is cut with a flat back.  Is that enough mud to hold it?  These are 1.25-1.5" thick and none too light.

Enough mud??  That depends on what toothed trowel you use. 
 

A 1/2"x1/2"x1/2" square tooth trowel puts a lot of mud on the surface. 
 

Just butter the backs if you are not comfortable. 

Right, but a 1/2" tooth means about 1/4" squished in place.  All the videos I was seeing were using a full (non toothed) back buttering of about 3/4" and squishing it to 1/2"

I'll add your technique to my test pieces and let you know.  Right now I'm a little stalled.  The mantel is taking longer than anticipated.  Troubles with my planer, but I got it fixed now.

The stones will be a little tough to butter with a toothed trowel.  Some of them are 4" tall or so and they would be fine, but some are not very tall, like 1" or less.  I suppose I could trowel them vertically, but I'm told that's a no-no.

m4ff3w said:

frenchyd said:

In reply to Curtis73 (Forum Supporter) :

Do you see the stone on that wall?  Yes it's actual stone, some granite, bricks, etc. some 60-80 pounds as much as 8 inches deep.  I put that up on the wall over 20 years ago. Just mortar and Brick ties.  In the summer the temps get well over 100 and during the winter as low as 40 below. Examine it carefully,  there isn't a single crack anyplace. No loose stones rocks or bricks.  Just have them damp when you put the mortar on. 
Since they are exposed to rain, sleet, hail, and snow I made sure all the surfaces sloped away from the wall so water wouldn't pool.  

That's really good looking, can you share some more pics - or even make a new thread with lots of pics?

I've got a lot of pictures I've posted over the years but I'm trying to convince Curtis to just do it. I was scared the first time I tried. It's not like playing a Stradivarius Violin. Pretty hard to hit a wrong note.  

In reply to frenchyd :

Yeah, but you know me... I have to research everything to the point of beating several dead horses.  I'm on dead horse number 3 right now.  Once I get the mantel in place, I'll be a mudding fool.

Jump on in, it's fun. The worst thing that happens is a stone decides to fall off and lands on your foot. Don't ask how I know. You pick it up, clean it off, curse at it and re-apply mortar for round 2.

Mine worked out great, yours will go the same way.