Input requested... May have goofed up

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NickW

Minister of Fire
Oct 16, 2019
1,365
SE WI
So I am on day 6 of installing Cast Natural Stone on Durock over the chimney chase and fireplace surround. Using modified HD mortar mixed just a little thick. To spec the stones seemed to want to slide so I went a little thicker with spacers. I just read that I should have been wetting the Durock before installing the stone, which I haven't been doing. Should I go pick up a spray bottle and re-wet the mortar to make sure there's enough moisture for the mortar to properly cure? The stone seems pretty solid, but I did knock a couple of the bottom ones off when removing shims when the mortar was thumbprint cured and had to reinstall them.
 
But you understand my reasoning correct? With full cure not being until 14-28 days, by introducing more moisture on day 6 I could potentially head off future issues...?
 
Mortar is going to cure 95% within a day and that last 5% is going to be spread out over a long time. If you only get 1500psi strength instead of 2000psi strength, is it going to make a difference?

If it makes you feel better, squirt some water on it.
 
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I think it's too late. And spraying the stone or joint not doing anything. I put stucco wire on sheetrock wall's then a scratch coat then the motor / cultured stones. It is solid.
 
I guess only time will tell. Looks very good. Still needs grout, but that will have to wait until next time up.
IMG_20230323_161544_01.jpgIMG_20230323_161545_02.jpg
 
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Could turn out to be bad news for you.

Don't know if you know anyone in the trades you could ask if they think it'll be alright and don't have to "tiptoe" around the chimney the rest of your life worrying about a rock of 5 falling off.

If, they say it's best to take it down and start over, please listen to them. It would be a PITA but worth it.

I don't think spraying water onto the rock/mortar would help out one bit.

Looks like you're doing good work. Good luck!
 
Leave it alone, it will be fine.
Do you know how many people do that work professionally that dont read the instructions and say "Ive always done it this way"
The fact that you only had a few stones have an issue over the entire job is telling, that overall the job was a great success assuming you put enough mortar behind each stone. Ive seen people use a trowel with v groove like they were laying tile on the floor. That's where you may run into issues. And even then likely not. Using a metal lathe backing on top of cement board is another way to stabilize a job like that.
You said these were cast stones, so they likely weigh about 1/3 the actual weight of a stone too.

I wouldnt worry about it until it became an issue. Maybe you'll get a few pieces that come off that you must remortar with a small amount of modified cement mixed in a paper bowl. Big deal. Now if they all start failing and falling, then you know that eventually you will need to rip it down and start all over.