Expansion and contraction questions

The Great Oz

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bryan
Concrete slabs always have expansion strips or they'll crack when they get warm. Granite expands and contracts a little less, but I'd guess is might be safer using a urethane caulk with really good adhesion/expansion rates. Flexibility in this use probably trumps hardness or total toughness.

Guess is the word, someone in the business of installing outdoor granite in your area may have a different idea.
 

Dolly Llama

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not even going to pretend how to fix it structurally ....

as far as "time" of year to apply goop ..when weather is stable and above 50 til goop is cured is a good rule of thumb

it's outdoors ...it's going to expand and contract regardless


.L.T.A.
 
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not even going to pretend how to fix it structurally ....

as far as "time" of year to apply goop ..when weather is stable and above 50 til goop is cured is a good rule of thumb

it's outdoors ...it's going to expand and contract regardless


.L.T.A.
It’s gotta be wood structure, with stone over...
Just a guess...
Right, LAR?
PL 400 for the fix?...
Especially because they don’t want to dismantle, and start again.
The proper fix is starting over...
 

clean image

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As I remember it. MIA does not recommend true epoxy in seams as the bond strength may cause the granite to crack different location.. that is why polyester is recommended.

this is one reason I question SGA in area of known movement...however maybe the addition of so much grout weakens it to the the point it looses its bond strength.

You could use shims on top of backsplash possibly to somewhat level uneven seams. Must be be careful as u can risk cracking.....

with known movement, polyester resin will eventually fail

I would recommend limestone gel. It gets hard yet allows 14% movement. It does require a higher level of installation skill however, as color adding/ matching as it comes translucent, and it cures much different and you can’t process it like poly... and it’s expensive...

On side note, we are doing a anti slip , epoxy treatment for a commercial job that slightly trumps limestone gel cost....@ $500 gallon.
 
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As I remember it. MIA does not recommend true epoxy in seams as the bond strength may cause the granite to crack different location.. that is why polyester is recommended.

this is one reason I question SGA in area of known movement...however maybe the addition of so much grout weakens it to the the point it looses its bond strength.

You could use shims on top of backsplash possibly to somewhat level uneven seams. Must be be careful as u can risk cracking.....

with known movement, polyester resin will eventually fail

I would recommend limestone gel. It gets hard yet allows 14% movement. It does require a higher level of installation skill however, as color adding/ matching as it comes translucent, and it cures much different and you can’t process it like poly... and it’s expensive...

On side note, we are doing a anti slip , epoxy treatment for a commercial job that slightly trumps limestone gel cost....@ $500 gallon.
Good post..
 
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I like your idea of using expanding foam as a backing material.
Just have to make sure to use the stuff that has minimal expansion. Otherwise, you’ll create a whole host of other issues.
I’ve seen people use expanding foam, and it wrecked the door frame it was used on beyond repair....
the regular stuff will just keep expanding until it reaches its max..
 

Mikey P

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Just have to make sure to use the stuff that has minimal expansion. Otherwise, you’ll create a whole host of other issues.
I’ve seen people use expanding foam, and it wrecked the door frame it was used on beyond repair....
the regular stuff will just keep expanding until it reaches its max..
Oh I know all about it that uses a lot of it at our cabin ..apparently the stuff is made out of Swiss cheese cuz the rats and mice love it
 
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