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Posted

Couple questions for you brethren that have worked lots of masonry.

Large house - nearly $1M - 10 years old. They used real stone cladding on the lower part of the front walls. There aren't any steel lintels and it looks like the stonework might be resting on a masonry ledge with an overhang of about an inch and a half. There isn't any evidence of weeps or flashings at the base of the veneer.

I examined and scanned the interior walls very closely for any hint of moisture intrusion and saw none. The base of these walls is pretty thick, so I intially thought that the foundation extended the full height of this stonework and that the veneer is fully grouted and mortared directly to the face of the concrete; however, after checking the tax assessor's site I think I was wrong.

The only photo in the tax file is a fuzzy black and white of the front of the house. It shows that at the time the photo was taken the EIFS lamina had already been applied and that the front stoop and the stonework were not yet completed. One can clearly see in the photo that the lower part of the walls is covered with what looks like a layer of black building paper. I suppose it could be a coating of waterproofing over concrete but one can see where it looks like they still had a piece of paper to apply at the corner of the garage when the picture was taken.

It's hard to tell whether the stonework is being installed on top of a concrete shelf or is being applied lick-n-stick fashion the way that faux stone veneer is installed. I think that because of the average thickness of this stone and the fact that I can't see any wire lath, that it's resting on the ledge with some overhang and they simply did so without any weeps or flashings. It's a tough nut though. Wish the photos were better or I'd had as-builts on-site like I normallys see when I do these high end homes. I thought I'd pass it by the brethren to see whether folks concur.

The second photo below gives you an idea of the average thickness of this stonework (Please don't comment on the cracking, I've got that handled.), the third shows a section of the wall and the fourth shows the bottom of the stonework where it overhangs the edge of the foundation. No sign of any weeps or through-wall flashings and it looks like they might have had a 2 by 4 against the face of the ledge as the stones were mortared in place.

Mike, you're a former mason; Kurt, you live for masonry and Bill, you've seen this stuff when it's been a couple of hundred years old. In addition to the lack of flashings and weeps and the issues that can cause, are you guys seeing anything else here that I need to be concerned about?

ONE TEAM - ONE FIGHT!!!

Mike

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Posted

I'd be surprised if there wasn't a little water getting in and staying there, or maybe it's drying to the interior.

Tough call without tearing it open. Lacking visual clues as to any problems, it's tough to know where you'd tear it open to find anything.

Posted

IMHO, I can't imagine stone veneer that thick not being on a ledge and supported by the foundation. That's way too much weight for paste and stick. It was EXTREMELY common for us to be left installing 6" of stone veneer on a 4" ledge, which while being a pain in the ass to get started off of, is fine in terms of support. As I've hashed over too many times: masonry has an extremely easy life in a residential setting. The tallest masonry structure is in Philadelphia, PA and it's about 54 stories of solid masonry. Of course some of it's walls at the base are a staggering twenty-two feet thick. [:-bigeyes But, heck brick in the residential arena is kinda like Hulk Hogan hanging out on a playground.

The only paste and stick stone installation I ever (consistently) saw done during my career, was done by South American immigrants, and I never cared for it: They used to lay up flag stone (like you'd see in flat work), held tight temporarily against the wall with furring strips. Tie wire was nailed to the wood framing and pulled through the stone veneer, to be twisted tight around the furring. When the stone was set, they'd snip off the ends of the tie wire and remove the furring. There was no expanded metal lath behind it! (exclamation point appropriately employed [:-party]).

It doesn't take a rocket scientist to figure out that's not going to last very long. I saw that done in the late 80's, and I bet some child has probably been hurt or crushed by it coming off the wall already. I HATED that installation, and can't understand why local building departments ever blessed it.

Posted

Hmmm,

I just blew up a section of the last photo and now I'm wondering if there is a weep there and I just didn't see it. See the dark thingy near the top of the photo below? It looks like an oval opening of sorts but I've never seen anything like it before. It's clearly in the center of the section of mortar bed that hangs off the wall. Could it be a piece of clear plastic tubing that's compressed to an oval shape?

Maybe it's just a piece of flotsam stuck in the mortar. Dang, I really don't feel like driving the 30 miles out there to look at this again.

ONE TEAM - ONE FIGHT!!!

Mike

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Posted

FWIW, Back in the day, we always installed weeps in brick veneer - open head joints every fourth brick or so. But back then, Mike, unlike brick veneer, stone masonry was always solid right to the wall sheathing. That was the typical installation. It was 30# felt over plywood, OSB or Sturdybrace. The stone veneer was laid up and solidly packed to the felt with stone mortar and chinking - no cavity, Mike. There really can't be a cavity. While the stone work is setting up, it needs something as sturdy as the wall framing to rest directly against. (It just ain't at all like brick or blockwork). Wall ties secured the stonework to the framing.

Of course, stone mortar isn't like brick mortar. If you tried to use brick mortar in a stone install, it would collapse for two reasons:

1. Brick mortar works with bricks because they're dry and immediately absorb some of the moisture out of the mortar, which is actually a part of what makes the two bond so well. Stone isn't porous (well, not very) so it won't absorb much moisture at all.

2. Because of #1, brick mortar would stay wet too long, and the weight of the stone would soon gush the mortar right out of the wall.

So, stone mortar is portland and sand mixed just wet enough that if you grab a handful and squeeze it, it stays together in a clump. That's perfect stone mortar, but you still can't go over about three feet in vertical height with stone (thirteen feet max with brick) in a day.

Bottom line: If the house has any age on it, weeps aren't likely, because a cavity behind the stone is VERY unlikely. It's darn near impossible to intall stone veneer with a cavity behind it. It'll fall down, before it sets.

Posted

I agree with Mike. I doubt you'd find weeps in a solid stone wall 10 years ago.

Some of this goes to what Mike was saying about the mortar. I'd have to see the mortar up close and personal to have an opinion that was worth anything.

Posted

I agree with Mike. I doubt you'd find weeps in a solid stone wall 10 years ago.

Some of this goes to what Mike was saying about the mortar. I'd have to see the mortar up close and personal to have an opinion that was worth anything.

An interesting and deceptive thing about stone and mortar: Sometimes you'll see stone veneer that looks like it was laid up with wet mortar, because the joint is struck. In cases like that, the stone was STILL laid up with mortar as I describe and raked (a special tool that scrapes out the stone mortar to a prescribed depth, when it's almost completely set up but soft enough to still scratch out). Then, when the work is set, the wetter mortar is pointed in and struck.

You can't lay stone with wet mortar. It's impossible - I promise. [:-graduat

If the mortar used to lay up stone is even the slightest bit wet, it's disaster in just a few vertical feet.

In other words, when you see stonework laid up with that classic "V" joint: it was added later. Trust me...

Posted

Bottom line: If the house has any age on it, weeps aren't likely, because a cavity behind the stone is VERY unlikely. It's darn near impossible to intall stone veneer with a cavity behind it. It'll fall down, before it sets.

Hmm,

That's interesting. I found this on the web a little while ago.

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What you say makes sense though. The stone used is unpolished granite so it's not likely to be porous and if they used a good stiff mix of PC and sand to solidly pack that wall it isn't likely that water could really collect behind it.

Wish I knew more about local stone mason practices. I just don't see it that often and when I had seen it before it was always in older structures. Guess I'll have to make a few phone calls in the A.M.. Thanks for the insight, Gents.

ONE TEAM - ONE FIGHT!!!

Mike

Posted

The detail you show, is a bit unique in that the stone is very square, and the joints are quite tight. In this case, yes, if you wished to maintain a cavity, you could probably do it, because of the stone's shape. Typically, stone is so irregular in shape that it relies more heavily on the mortar to stay together while green.

Stone, in general, will absorb and tolerate very little water during installation, before it becomes as slippery (in the wall) as a greased watermelon. And, the more pressure you add to the system (weight), the more slippery they become. What's even funnier is that once this begins to happen, the more you monkey with it, the worse it gets. In other words, if you've started with to wet a mix, and it begins to get unstable, you have two options: 1. stabalize it with temporary bracing. 2. knock off and come back tomorrow when the mortar has set.

That being said, If you presented me with that particular detail and showed me a pile of very square stone insisting it had to be done that way, I could. But notice the note in the detail: "Open Cavity (if a sawn stone with a controlled bed depth)" I rest my case. [:-thumbu]

My experience is with more typically random stone shapes, such as field stone. While most stone is actually quaried, there is a term for stone that is more square. I believe it is "quarried", but it's been too long. You'd still need the stone mix I described or mortar would begin to ooze out of the lower joints as you piled on the stone.

Your photos appear to show some classic granite and the stone shapes are random enough and the joints big enough that I doubt theres a cavity.

Posted

That's interesting. I found this on the web a little while ago.

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What web site did you find that on Mike?

What do ya wanna bet it's a US Army document?

My pleasure, Mike. Happy to be of service.

Posted

That's interesting. I found this on the web a little while ago.

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Nah,

I googled "Weeps and Through-wall flashings in stone masonry" or some such and found it on one of dozens of sites.

Jeez, I never thought to check my Army references. I think I'm getting oldtimers disease.

ONE TEAM - ONE FIGHT!!!

Mike

What web site did you find that on Mike?

What do ya wanna bet it's a US Army document?

My pleasure, Mike. Happy to be of service.

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