[nwalch]

What heppends to cement when it goes past its use by date. I only want it to cement some fence posts in so its hardly a major structure (although I know the wind can give fences some hammer in gale).

If it weakens it can I just put a put extra is. I've got a few backs left from last year when I didnt get round to putting some fence posts up on the plot.


Nick

[Lardman]

Strictly speaking if its been open to the air (even bagged) it will start to absorb water. The chemistry behind it on easy to find with google.

Practically, I've had an open bag in the utility for 2 years that I use for patching, and Id have no questions at all about using it to mix concrete for fence posts and long as its still powder and mixed well.

If I was building a house or rendering Id be a little more concerned and for the sake of a few quid Id buy new, but its basically dead weight on the end of a fence post.

I await a telling off by those who know better 

[RichardA]

take a small sample of the cement and mix it up in an old bucket etc to same proportions as you intend for your fence posts. If it sets hard and looks OK then use it otherwise dump it.
R

[GrannieAnnie]

My Brian said if it hasn't gone hard, then should be fine to use!

He doesn't use plaster past its use by date as it can go 'off' very quickly, which means it can stick the trowel to the wall within seconds!!!   

[Lardman]

He doesn't use plaster past its use by date as it can go 'off' very quickly, which means it can stick the trowel to the wall within seconds!!!   

Round here thats know as "window fitters special" plaster.

[GrannieAnnie]

 

[Tenhens]

If it's exposed to the atmosphere ie open bag it will air set but stored in a dry place will keep. I have'nt used it myself but I have heard good reports about Postcrete which is a ready made product that you apparently dig your hole, put the post in and fill with the Postcrete and then water. I don't know how much it costs.

The date on the bag is like a 'best before' rather than a 'use by'