Waterproof cement additive

[purplyblue]

I've just cemented a load of outside pointing where rain was coming in, and part of an uneven concrete floor (4 parts sand, 1 cement). The cement hasn't gone off, 2 days later. I've never had this problem before. Was this the waterproofer/plasticiser (from B&Q) being too strongly mixed? Or just the cement being a bit old? Don't want to make the same mistake again!

 

[ajrobb]

I've seen mention in another thread that old cement won't set. If it has lumps which can't easily be broken up by hand, it might have lost its setting agent.

 

[garyo]

sounds a bit like old cement to me... I guess you could make a test lump of mortar with the cement and don't add plasticiser to test the cement.