Cement Shelf Life

[fidom]

I have a lot of brickwork that needs pointing, mainly inside and outside my farm buildings. I fit this in with various other jobs and try to make a bucket of mortar each day. At this rate a bag of cement lasts me about 5 weeks but after 2 or 3 weeks it starts going lumpy and I end up putting it through a sieve to remove the lumps. It is stored in my slightly damp tool shed. I've noticed the paper sacks have a series of small holes punched in them. I always close the top of the sack and put a brick or something on top to try to keep the cement fresh. I did try storing a couple of unopened bags inside the centrally heated house but it still went lumpy.
I was at my place in UK in March and had to sort out stuff in a storage shed. I found there was half a bag of Mastercrete cement left over from a job I did a couple of years previously. I expected this to have set into a solid lump but no, it appeared to be in perfect condition! The Mastercrete cement came in a plastic sack instead of paper. Are the paper sacks and air holes used to deliberately shorten the shelf life of cement?

 

[rabu]

Hi, dont know about the air holes in sacks being deliberate, dont realy know the purpose unless its for heat as when cement is made and bagged its still quite warm. One thing i do is buy normal cement, no pertucular one, sometimes lafarge (formely blue circle) or rugby premium as thats what merchants has in at the time. But i put the bags in a plastic rubble back, fold top over and put bag of sand on it then stand bag on 2 tiling battens to keep air flow under it . Iv kept cement few months in slighlty damp garage like is ans its been fine after. Hope this helps.

 

[fidom]

Thanks rabu, I will try that.

 

[foxhole]

Its down to the moisture content, kept unopened the plastic bags last months.

 

[Dave54]

Yes it's the moisture content that does it. I keep mine more or less the same as said above. Put the remains of the bag in an old feed sack, and tie off the top with baler twine after expelling the air. Get it off the floor as well. It keeps for ages like that, although I'd only use it for non critical jobs after it's been kept like that for a while.
When I was out working I used to use a tip my late father-in-law gave me years ago, and kept one of those big plastic clip on top paint tubs with some completely dried out sand and cement ready mixed in the van. Keeps for ages.

 

[mattylad]

When painting the wall est, once finished I wash out the 10l tubs and use them for keeping cement etc in.
Lasts for ages then.