Mortar or Cement or Concrete? These terms really are missused very
often but I will assume that it is indeed mortar (as in laying bricks,
block) a premixed sand cement and lime/fireclay. Generally bagged
products will harden from just humidity but if it is still powdery im
sure it is fine. As a precaution (to avoid hardend parts in your mix)
as you take the mix out of the bag either pass it over a screen or just
run your hands thorugh it (gloved) to check for lumps....
wrote:
I've had an opened bag of mortar in my garage for about a month. I did
a small repair back then and only used a few scoops of it. I have a
rag covering the opening and the mortar is still powdery. Can I still
use it, or should I throw it away?

Mike