Out of date postcrete

[tjw78]

Can I use out of date postcrete, or would I be wasting my time?

I'm laying a small foundation for a brick bbq in the garden and the previous owners of the house left a load of postcrete in the shed. It would be good to save the money on buying new, and it would be good to use it up, but the date on it is 2008.

 

[Burnerman]

If its still powder, it'll be fine.....usually the bag is one solid lump though!
John

 

[tjw78]

There are several bags. They don't seem solid

 

[Burnerman]

The thing is with postcrete, its for just that.....the time you get to actually trowel and work the stuff is very limited - less than 5 minutes on occasion.
John

 

[rjm2k]

Yes, as above this stuff sets very very very fast! You are supposed to fill a hole with water, chuck the stuff in with the post and mix it around very quickly.

 

[xdave]

If you are using postcrete for a BBQ foundation then you'll need to add some larger aggregate into the mix before water, and a handful of fibres would be a good idea too. Dig your hole, peg your levels if you need to and pour the dry powder into the hole approx. 50% deep. Add the aggregate and mix well then make a series of holes/wells in it and fill to submersion with a hose. Mix well with a stick as with large volumes it is easy to add too little water. Then compact/vibrate it with the top of a rubber mallet in a plastic bag or block of wood. By this time the postcrete will be starting to set so quickly add the remainder of the powder, mix in further aggregate and repeat. Keep a small amount of mix left over in case you end up with too much water the second time round so you can add it to the top. Level by hand/tamper but don't float it or all the cement will rise up and weaken the end result.

Personally I would just buy a bag of cement and a few bags of ballast (already mixed aggregate for concreting) and make some concrete up. It will give you a longer working time and will be much stronger. Postcrete is really meant for adding bulk around a fence post and maybe for setting drains in light traffic areas.

 

[tjw78]

Its not a large area - about 40x30 inches

I've built a frame, and filled the bottom with some hard core I had lying around. There is about an inch and a half to the top of the frame.

 

[retrieverman]

Yes, as above this stuff sets very very very fast! You are supposed to fill a hole with water, chuck the stuff in with the post and mix it around very quickly.

no u pour the postcrete
In the hole then pour water on top and just let it soak through