Is out of date cement ok?

Arex24

New Member
I have a number of bags of Blue Circle Mastercrete Cement (the blue and yellow plastic bags) that I bought years ago. They were bought to render my raised driveway but certain events meant this got delayed. I still have the bags stacked up in our lean-to which is in the middle of being insulated and turned into a proper utility room so it’s water tight, doesn’t get damp etc. The bags used by date is Nov 2021, which is obviously a long time ago!
Blue Circle advise against using out of date cement because of health and safety reasons (here), but don’t say anything about its actual usage and effectiveness. The cement is still earmarked to be used for rendering, so are they still ok to use? I haven’t opened any up, they’re all still sealed, so I don’t know the condition. What should I look for, and if all being well can I still use them for this application? Thanks
 
I still use 5 year cement in plastic bags & opened bags stored in plastic tubs.
It takes longer to set, but I would not use it on anything critical.
 
If the cement is still in powder form, and not set into lumps or a single mass, then it will likely still be in usable condition. I can't see how it can go "off" - it sets by chemical reaction with the water you add (not as commonly said by "drying") and if that hasn't happend then it'll probably be OK. I guess though you probably shouldn't use it for anything structural, just in case, but for driveway use it'll be fine
I also can't fathom what Blue Circle means that it shouldn't be used for "health & safety" reasons. Clearly you need to use gloves and avoid breathing in the dust when using cement but this is the same no matter how young or old it is.
 
If the bags are intact and the cement unlumped it'll be fine.

The only H&S factors I can see would be that Blue Circles financial jhealth would be a bit better if you bought more of their fine product
 
Thanks for all the advice. There’s a part open bag on the top, which has no lumps and is still powdery as normal, so it’s highly likely the unopened bags will be fine.
It is still earmarked for rendering the driveway only. I’ve got no structural or critical jobs on the horizon anyway. If I had, I’d buy new.
I think I’ll mix it with some new bags just in case, but I don’t see how it could go off either. Blue Circle don’t say it does, as they just say “The use by date on cement is related to health and safety regulations about ‘chromium VI’ which can cause allergic dermatitis.” But like ChrisJP said, you should be wearing gloves and avoiding breathing it in anyway.
 
They have to say don't use out of date in case it takes days to set and people complain, easy to test, just mix some in an old container and stick your finger in it the following day.
 
Using outdated cement poses risks despite its physical integrity. The primary concern is pre-hydration, which affects chemical composition and bonding capabilities, potentially compromising structural integrity and safety,
which is why I advise you to buy newer batches for your rendering project. If you still want to use the out-of-date one, inspect the bags for signs of moisture ingress or visible damage before opening them. Even if sealed, prolonged exposure might affect their usability. Consult local building codes or experts for specific guidance. :)
 
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