Lumpy cement

[aaront]

The last couple of times I have knocked up some cement its finshed with small hard pea sized lumps - this is a nightmare when trying to render.

Anyone got a clue as to whats causing it? I have knocked up plenty of cement over the last few months so there's nothing wrong with my mixing!

 

[masona]

Usually too much cement,keep mixing it until the lumps disappear or damp/wet inside the cement bag causing lumps to harden or old cement.