Hi everyone, I have half a bag of mortar that's been sitting in my basement for at least 3 years. It's still in powder form. is it still any good?
Throw it away.
It is cheap and has been opened and will not be as good as new bag.
Any problems are going to cost you more than another 1/2 bag (which you cannot get).
Even contractors throw away a 1/2 bag before the next day or week-end.
thanks, I'll throw it out.