Apply stone verneer over sealed concrete ? - DIY Chatroom

Roy Rowlett · 04-13-2009, 10:03 PM

I want to install man made stone verneer ( a concrete product) which is approximately 1.5 inches thick, on a poured concrete wall that has been damp-proofed with a tar type sealer. How do I insure that the mortar/adhesive will adhere to the sealed wall? Will the mortar/adhesice stick to the tar? Do I have to apply a metal lathe with some type of concrete anchors?
Thanks

jomama45 · 04-14-2009, 12:21 AM

Quote:

Originally Posted by Roy Rowlett

I want to install man made stone verneer ( a concrete product) which is approximately 1.5 inches thick, on a poured concrete wall that has been damp-proofed with a tar type sealer. How do I insure that the mortar/adhesive will adhere to the sealed wall? Will the mortar/adhesice stick to the tar? Do I have to apply a metal lathe with some type of concrete anchors?
Thanks

No, the mortar will not stick to tar. I would suggest you get the grinder out with a diamond (or carberendum) wheel. After you clean that off, I would suggest you apply a slurry coat of bonding agent & cement.

Tscarborough · 04-14-2009, 08:50 AM

Or just lath it.

wildcat · 04-14-2009, 09:47 AM

Quote:

Originally Posted by Tscarborough

Or just lath it.

This, especially if above grade you'll need a gap between the veneer at the wall and weep holes at the bottom to allow moisture to get out. This will also need proper flashing detail.

Roy Rowlett · 04-14-2009, 10:35 AM

Quote:

Originally Posted by Roy Rowlett

I want to install man made stone verneer ( a concrete product) which is approximately 1.5 inches thick, on a poured concrete wall that has been damp-proofed with a tar type sealer. How do I insure that the mortar/adhesive will adhere to the sealed wall? Will the mortar/adhesive stick to the tar? Do I have to apply a metal lathe with some type of concrete anchors?
Thanks

This is a basement wall that I waterproofed. I put the tar up too high above grade, onto the part that I want to install the verneer on.
Instead of grinding or lathing, perhaps I could sand blast it off. That seems easier to me.
Since it cleans up with mineral spirits, maybe I can loosen it with mineral spirits, or muratic acid, then pressure wash it off. Then I could etch it with the muratic acid. That seems like it would make the surface able to hold the mortar/adhesive.
Any thoughts on this?

yesitsconcrete · 04-14-2009, 11:53 AM

not sure how much s/b'ing you've done but, it it were mine, i sure as **** wouldn't - 1st place, you'll need, at least, 100sfm @ 90psi out of a 1/8" nozzle to get any decent work,,, next, the asphalt cement ( tar ) will act as a 'resist' 'cept the thin spots'll blow off quick & you'll get a dimple'd surface,,, the cement'll also melt from the sand's friction & make a larger mess,,, neighbors'll also complain about the dust.

here's my method - 20# propane tank, weedburner torch, & ice scraper - soften the coating & scrape off,,, next apply s/s expand'd metal lath & mortar your rocks to it.

NJ Brickie · 04-14-2009, 02:37 PM

Quote:

Originally Posted by wildcat

This, especially if above grade you'll need a gap between the veneer at the wall and weep holes at the bottom to allow moisture to get out. This will also need proper flashing detail.

I've never seen a cultured stone application with an air space and weep holes.

Roy Rowlett · 04-14-2009, 03:02 PM

Quote:

Originally Posted by NJ Brickie

I've never seen a cultured stone application with an air space and weep holes.

I think he thought it was a retaining wall. That is why I clarified my question after his comment. I think I am going to try loosening the tar with a solvent, then pressure wash it.

yesitsconcrete · 04-14-2009, 04:12 PM

lest anyone think my earlier suggestion was ' pie-in-the-sky ', resolving problems of this sort are normal prior to completing our work,,, this method isn't just flip of the coin but, rather, 1 that's adopted in the applied decorative concrete craft after trying all the other jack-leg approach's.

obviously you don't have to make a profit on work at your home NOR are you burden'd w/regards for environmental damage but those rqmts govern us,,, p/w'ing won't do squat imn-s-hfo ! ! !

Tscarborough · 04-14-2009, 07:51 PM

The trend is to put drainage behind adhered veneer. It is not one that I necessarily agree with, but that is one system of doing it. The cause is that just like with any other tried and true system, people take short cuts, that causes problems, and a new method is devised to "fix" doing it the wrong way (and provide for some profit opportunities along the way).
What I mean:

The proper wall system for adhered veneer should be exactly the same as for 3 coat cementious stucco, with the stone replacing the final coat:

Proper wall makeup:
backup wall:2 layes of waterproofing material:lathing:scratchcoat:browncoat:finishcoat/veneer stone

Normal adhered veneer stone application:
Backup wall:1 layer of waterproofing material:lathing:scratchcoat:finishcoat/veneer stone (and some people wetset the stone dierectly into the scratchcoat, further devolving the system.

If done properly, there is no need for the wall to be weeped. Done as the new "normal" method, you better weep it, and hope for the best anyway.

This poster's wall is different, though, and the waterproofing should be left in place, lath attached, a scratchcoat applied and the then stone adhered to that.

Roy Rowlett · 04-14-2009, 07:56 PM

Quote:

Originally Posted by Tscarborough

The trend is to put drainage behind adhered veneer. It is not one that I necessarily agree with, but that is one system of doing it. The cause is that just like with any other tried and true system, people take short cuts, that causes problems, and a new method is devised to "fix" doing it the wrong way (and provide for some profit opportunities along the way) of applying the wall system.

What I mean:

The proper wall system for adhered veneer should be exactly the same as for 3 coat cementious stucco, with the stone replacing the final coat:

Proper wall makeup:
backup wall:2 layes of waterproofing material:lathing:scratchcoat:browncoat:finishcoat/veneer stone

Normal adhered veneer stone application:
Backup wall:1 layer of waterproofing material:lathing:scratchcoat:finishcoat/veneer stone (and some people wetset the stone dierectly into the scratchcoat, further devolving the system.

If done properly, there is no need for the wall to be weeped. Done as the new "normal" method, you better weep it, and hope for the best anyway.

This poster's wall is different, though, and the waterproofing should be left in place, lath attached, a scratchcoat applied and the then stone adhered to that.

Thank you all for your professional recommendations.
As a non-professional, I need some guidance as to how to attach lath to a poured concrete wall.
Thanks

Tscarborough · 04-14-2009, 08:04 PM

Hilti gun and washers.