Thinset expiration dates

I've seen posts saying not to use thinsets that are more than a year old (date on container). Why is this, and what would happen if you did use older material? I recently purchased 4 bags of Laticrete (3 of 255, & 1 of 272) and couldn't find the date until I got home. The date marked on bags is April 2011.......Now what?
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Steve

Checking date codes on Laticrete bags

That thin-set is garbage. Do not use it at all.

We try and not use any thin-set older than 3-6 months.

I to recently bought an expired bag of Laticrete thin-set. It's in the truck ready to return to the place I bought it from. Here is how to check the date code on Laticrete Thin-set.

Laticrete makes the best packaging in the business but two year old thin-set will be nothing more than sand once mixed.

Send it back.

If you get any grief over it call up LAticrete Customer Service and they will set the seller straight.

Often product gets poorly shuffled in a warehouse and this could be the result of this. Or a savy warehouse manager was trying to pass off dated product on you.

Either way your out the trouble to go back and switch it.

Sorry.

ALWAY CHECK THE DATE CODES BEFORE LEAVING A STORE!!!!

This is one of my own rules and I broke it just three weeks ago. And read the bags - often there are primers or other liquids these products detail for slurry coats or unique installs.


You can find the local Laticrete offices here and look up their phone number. http://www.laticrete.com/contact_us.aspx

SH140 said:

I've seen posts saying not to use thinsets that are more than a year old (date on container). Why is this, and what would happen if you did use older material? I recently purchased 4 bags of Laticrete (3 of 255, & 1 of 272) and couldn't find the date until I got home. The date marked on bags is April 2011.......Now what?
__________________
Steve

Click to expand...

Saving a failed installation

If it helps any - the simple fact you checked this out most likely saved the installation from failure or from being less than perfect.

The portland cement in thin-set absorbs moisture from the air causing it to set up before mixing. This results in a thin-set with little to no strength.

Good on you for checking.

TWO THUMBS WAY UP!!!

I know checking Mapei and Ardex bags can be a nightmare. I have decoded much of the Mapei code and have it outline here.

The Ardex code and how to read them is outlined here.

The portland cement in thin-set absorbs moisture from the air causing it to set up before mixing. This results in a thin-set with little to no strength.

Click to expand...

I'm wondering, would you be able to feel a difference in the bag (like it's one solid block) if it's expired? The one's I bought seem to feel like I imagine they should ( loose and soft).

I like to think of it like expired food in the refrigerator. It might still be good, or it might tear your guts out for the next week or so.
I'd rather throw it away and not take the chance.

Unfortunately, old thinset often doesn't look much of any different. Because moisture comes in so slowly, often what you end up with is grains of cured cement. Because they didn't get fully wet, they don't bond together, but once cement has cured, it's basically inert. If there's enough left that's uncured, it might hold together, but it will not have anywhere near the stated strength.

The data or info on the subject of how much a thin-set weakens over time is yet another interesting thing that could be tested. Our worst failure was from some old self levelling product about 8 years ago. Complete failure. Had to rip out the entire floor and do it over (After we set and grouted the floor).

It's rare that I see any thin-sets that are past their good to go date - next time I find a bag I'll bring it home and test it side by side with a fresh package. I think this will interesting observation.

I'll use the same procedure for testing the thin-set as I'm using for the Spider Web testing.

If your shopping for Grout or Latex Admix this weekend in North Vancouver. Careful where you purchase them. These products on the shelf the other day - ready for sale but long since expired.

Do you know to check these dates? You should.