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Stone Adhesive
2

Stone Adhesive

Stone Adhesive

(OP)

Stoneworks weight a lot and the back side is very smooth.. do you trust the so called stone adhesive is enough to hold the stone works for long time?

RE: Stone Adhesive

They often use an adhesivie for securing capstones on segmental precast retaining walls and also for headstones in some cemetaries... you might check with these people...

Dik

RE: Stone Adhesive

Stone panels are often anchored with copper wire, for what that's worth.

RE: Stone Adhesive

I would not trust stone adhesive to hold stone in place on a permanent basis.

BA

RE: Stone Adhesive

It depends on the configuration of the stone and its thickness as to whether you can use adhesive. If stone panels (18"x18" or 24"x24") installed on vertical surface, do not rely on adhesive. Use mechanical attachment, either with wire or pins. I would not use copper wire as corrosion is an issue. I would use stainless steel pins or wire, allowing for thermal movement.

If small pieces of stone or faux stone, cementious adhesive (thinset) or mortar can be used. Follow the instructions provide by the Masonry Veneer Manufacturer's Association guide (a copy is attached).

RE: Stone Adhesive

As Ron says, the configuration (weight, orientation, etc.) has a lot to do with the answer to the initial question. I wouldn't count on adhesive to glue a thick stone soffit in place, but I have used it for a thin veneer on walls many times. What is the difference between stone & ceramic tile with the correct adhesive?

RE: Stone Adhesive

The difference is weight. I don't feel too threatened by ceramic tile coming loose and falling down but I feel very threatened by large chunks of stone coming loose and bouncing around in unpredictable ways. They would be a threat to life safety.

BA

RE: Stone Adhesive

Nonetheless, people do use only cement to hold up absurdly heavy chunks of stonework or masonry:
http://en.wikipedia.org/wiki/Big_Dig_ceiling_colla...

However, bear in mind that the panel that collapsed was to be held in place with epoxied bolts; it was more poor execution that caused the failure.

TTFN
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RE: Stone Adhesive

I'm not so sure it's a good idea to be hanging rocks overhead using any kind of support system. I don't mind a boring old drywall or exposed concrete ceiling and would feel a lot safer with those than a bunch of suspended rocks, any one of which could kill me if it fell on my head. Who needs that risk?

If you want to give nature a sporting chance to kill you, take a drive through the Rocky Mountains. Eventually, if you drive long enough, you may get your wish but most of us don't really want to risk getting squashed as we go about our daily business.

BA

RE: Stone Adhesive

My point was that I can buy stone sliced to 1/2 or 3/4" thick just like a tile and possibly lighter than ceramic of the same thickness, & if I glue that to a wall, adhesive is perfectly acceptable. If I decide to glue 4" thick veneer stone to a soffit, I deserve whichever pieces hit me and probably a few that don't. Weight, orientation, & location mean everything when discussing the method of attachment.

RE: Stone Adhesive

IRstuff, the epoxy used for the Big Dig panels was severely deficient.

RE: Stone Adhesive

(OP)

The panel of natural stone each weights about 10 lbs and it uses polymer modified mortax mix for adhesion and if even one piece falls down. It can be completely fatal so I can't imagine having it installed.

Does anyone know where to purchase aluminum design that looks like stone and almost indistinguisable from stone in appearance but entirely aluminum?

Attached is the stone works (size 2.7 meters height and 2 meters horizonal) I want to emulate but made of aluminum or even plastic adhere to concrete external wall.

RE: Stone Adhesive

How is it going to fall out of a wall? It is very, very common to have a mortared stone or brick veneer on houses around here, 2 stories high. The stones are frequently 10-20 lbs.

I can see the concern of gluing it in an overhead position, but as a wall the weight is supported by the next stone down, and ultimately the foundation.

RE: Stone Adhesive

BA,

Good point! Life's risky enough without adding unnecessary risk.

I'm told that air brakes on trucks require energy to hold the breaks off. Therefore if the mechanism fails, the brakes engage. I don't know if that's true but, if so, I like it. That is, if the system fails it becomes safer, so to speak. Brilliant! But that's the opposite philosophy of suspending rocks, anvils, grand pianos, etc. above our heads...though it does make for some entertaining coyote/roadrunner cartoons...

RE: Stone Adhesive

(OP)
TomDot,

The 2.7 meters vertical and 2 meters stone design is suspended above in the second floor just below the ground floor entrance to a commercial store. It's not continuous down.

How can polymer modified mortal mix support 10-20 lbs piece to a vertical concrete wall (even roughen)??

RE: Stone Adhesive

Look into GFRC (glass fiber reinforced concrete.) It can be placed in a mold by hand (similar to fiberglass) to create a hollow panel. You can use integral color, or it can be stained, and it will copy the texture of the mold. It is commonly used for architectural restoration of old stone buildings.

RE: Stone Adhesive

Whoops, my earlier comment was in regards to it being suspended overhead. That being said, poorly constructed brick veneers do collapse on occasion and they're not dependent on adhesive, unless, of course, you classify the mortar as such.

RE: Stone Adhesive

"the epoxy used for the Big Dig panels was severely deficient." That would be poor execution in my mind, since they failed to check the adhesive.

As for these blocks, if there are no concerns about earthquakes, that's one thing, but without even pins, you count solely on the shear strength of the adhesive and the support of whatever's directly underneath. Seems to me that epoxied pins would at least provide some level of cantilevered support of the block and not just depend on the adhesive alone.

TTFN
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RE: Stone Adhesive

>>>"the epoxy used for the Big Dig panels was severely deficient." That would be poor execution in my mind, since they failed to check the adhesive.<<<

Perhaps so, but BA's point remains: if you don't suspend something above your head in the first place then it can't fall on your head.

Failures occur and we'll never be able to eliminate all risk from life. But whether gluing heavy slabs of ornamental stone above our heads for purely aesthetic purposes is a wise decision is another question.

RE: Stone Adhesive

I don't really see how this is any different than any other structural component. Lots of things we design could kill if they failed. That's why we do our calcs, and that's why specify a product with an ICC code report that shows a tested strength and the safety factors associated with it. It will also indicate the installation procedure.

RE: Stone Adhesive

"Perhaps so, but BA's point remains: if you don't suspend something above your head in the first place then it can't fall on your head."

I wasn't attempting to contradict that. But, not everything is solely about functionality; if it were, the world would resemble a Brutalist architecture catalog. My house, on the other hand, has decorative rock work panels that are glued on and goes up the walls to the bottom of the 2nd floor.

TTFN
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RE: Stone Adhesive

>>>I don't really see how this is any different than any other structural component<<<

It's not a structural component...at least, the stone isn't. The epoxy anchors arguably are, I suppose. But therein lies the rub. For a structural component such as a column or beam to fail it likely means that there has been dramatic design or construction incompetence or oversight, and even then there are often warning signs before it occurs. Epoxy anchors, on the other hand, only require a little bit to go wrong (dust in hole, water intrusion, etc.) for one of them to fail and then they do so with no warning. Add to that that in the scenario under discussion there could be hundreds or even thousands of them installed, and all it takes is for one of them to go wrong...a la the Boston tunnel incident. It's a lot of risk to take for a simple avoidable architectural element, in my opinion. We can't build things without structural components but we don't have to glue heavy stones above our heads.

But, at some point it comes down to our respective levels of risk aversion. I'm of the philosophy that I won't have a skydiving accident if I don't go skydiving. For others that particular adrenaline rush is worth the risk. We each make our own choices.

RE: Stone Adhesive

I can agree that, if this were considered just an architectural finish and no structural design was done, then I would definitely be uncomfortable with it. I would hope somebody (architect, contractor, building safety department) might bring this up as a critical item specifically.

I guess to answer the original question as written: I wouldn't just blindly trust the adhesive, I would want the hard testing data to back it up before I, as a structural engineer, gave the OK.

RE: Stone Adhesive

Structural design was done in the case of the Boston tunnel and, indeed, most of the anchors held.

RE: Stone Adhesive

In order to use the "lick and stick" method of Thin stone veneer, the stone can only have a max thickness and weight/sf. Otherwise it should not be done. There are industry standards for this method. I believe the weight limit is 15 psf or up to 1-1/4" thick max down to 3/4" thin. I can sleep at night knowing the mortar bed will hold this. The typical "adhesive" is usually basic mortar. Thin stone veneers are very common and when installed properly are just fine. Thin stone should only be installed in a vertical position. Most stone cutters will only supply the proper material. Read the specs.

______________
MAP

RE: Stone Adhesive

I would not rely on adhesive to hold material weighing 15 psf on a wall, particularly if it was high above occupied space. If the adhesive fails for any reason, the falling material has the potential to cause serious injury or death.

BA

RE: Stone Adhesive

(OP)

What if you use pure A & B epoxy adhesive in attaching the 15 psf stone to the wall of the second floor above the entrance of ground floor? Would it attach better as bond strength is supposed to be on the order of above 2000 psi?

RE: Stone Adhesive

Stone veneer should be supported at the bottom. Suggest providing a shelf angle. Tile adhesive can be used to support the veneer against lateral movement, but I don't agree that tile adhesive is "basic mortar".

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