Hi,

I have a 1m trench at the rear or my house ready for some concrete to be
pumped in later in the week (about 5m cubed).
The readymix people and the pump people said the weather isn't so cold that
I should put it off. But I'm not so sure.
I'm in the East Midlands and the daytime temps are set to be about 2
degrees.
Any advice would be appreciated.

TIA. bhads.

bhads wrote:
I have a 1m trench at the rear or my house ready for some concrete to be
pumped in later in the week (about 5m cubed).
The readymix people and the pump people said the weather isn't so cold that
I should put it off. But I'm not so sure.
I'm in the East Midlands and the daytime temps are set to be about 2
degrees.
Any advice would be appreciated.

Should be absolutely fine, if you want to make sure of it
then cover it up for a few days with a cheap "tarpaulin"
(the sort with eyes around, made of green plastic) from
Wickes or wherever.

bhads wrote:

I have a 1m trench at the rear or my house ready for some concrete to be
pumped in later in the week (about 5m cubed).
The readymix people and the pump people said the weather isn't so cold that
I should put it off. But I'm not so sure.
I'm in the East Midlands and the daytime temps are set to be about 2
degrees.

Never mind what the daytime temp will be, what is the lowest temp (ie
night-time?) likely to be, on the day of pouring and several days
afterwards?

www.pavingexpert.com, whose advice I trust, reckons the temp should stay
above 4 deg C for the 72 hours after pouring.

IANAE but I certainly think you're right to be cautious about doing this
at the moment. I know there are various anti-freeze type additives you
can include in the concrete mix; maybe the readimix folk are doing that,
and maybe that's fine; I wouldn't know.

David

If it is going below freezing a layer of straw then a tarp will do the
job.
If it is only dropping below freezing after dark ... then try and get
it poured as early as possible ... so it starts to go off before you
have to straw & cover.

bhads Wrote:
Hi,

I have a 1m trench at the rear or my house ready for some concrete to
be
pumped in later in the week (about 5m cubed).
The readymix people and the pump people said the weather isn't so cold
that
I should put it off. But I'm not so sure.
I'm in the East Midlands and the daytime temps are set to be about 2
degrees.
Any advice would be appreciated.

TIA. bhads.

The concrete "in the ground" will be fine unless it gets very cold, its
just the top few inches you need to worry about. Once its been levelled
you should spread a good layer ( say 4") of straw over the top to
insulate it and keep the frost off, if you can cover that with tarps or
plastic sheeting all the better. The concrete generates a lot of heat as
it cures and so will naturally protect itself from frost, its the
surface where the damage is done.


--
Nick H