I've got 2 and 1/2 bags of Dunlop Large Format and Natural Stone Floor Tile Adhesive left over from tiling a kitchen floor about a year ago. I think the adhesive was actually bought in Jan 07. It was used in about August of last year and was absolutely fine. I last used a bag in around October of last year to tile a kitchen floor of a property we let out.

What is the likely shelf life of this adhesive, and are there any indicators that it is still OK to use (ie still in powder form and not set solid)?

I've got a job coming up soon and this amount would sort it.

Unopened bags of addy should be used with-in 12 months, open is 6 months stored in a cool dry place.
I've come across bags of tile adhesive which a customer had, when opened the power was not as fine as it should of been, lots of lumps.
I made the customer buy some more adhesive, I refused to use it.

I would not use it, get rid, if you had any problems after laying tiles, you wouldn't have a leg to stand on.

If it's stored perfectly dry, powder adhesive can be store more or less indefinatly, but since that's never the case, a year is normally the shelf-life. The longer it's stored, the more likely it is that damp has gotten into the bag, and even if it hasn't turned lumpy, the performance of the adhesive may be degraded if used. If you're very confident it's been stored in dry conditions however, it's probably perfectly usable.

The chemicals which keep chromium bound has a half life of about a year too, so if you're sensitive to chrome, you shouldn't use cementious adhesives older than a year.

According to Bal.
Goldstar 6 months
CTF3 12 months
Rapidset grey 6 months
Rapidset White 12 months

I think the adhesive was actually bought in Jan 07. It was used in about August of last year and was absolutely fine. I last used a bag in around October of last year to tile a kitchen floor of a property we let out.

What is the likely shelf life of this adhesive, and are there any indicators that it is still OK to use (ie still in powder form and not set solid)?

If you look on the bag it should have a date of manufacture on it, and the shelf life.

if there's a doubt, bin it, much better to get new addy than take tiles up 'cos it's failed imo

ive found TOPPS own brand rapid (palace re brand) goes lumpy within 6 weeks.

Thanks for all your replies.

Doug said it best really.

If in doubt chuck it.

I am in doubt, so out it goes.