Concrete Mix for fence posts in Winter

[vards01]

Hi All,

Hope someone can help. I am putting up a lot of fencing next week (8 ft concrete posts 5ft pannels and 1ft concrete gravel boards), and I have seen the weather forcast...and its not good concreting weather 0 - 2oC, unfortunately I can not rescedule as I and my helpers have booked time off work. The only option I can see is a frost proofing additive, has anyone had any experience with these? I have spent allot of money on fencing materials and do not want it to go wrong.....wish I could wait untill the weather picks up but my 2 dogs keep escaping!! I have seen the post mixes available but for this quantity would just cost too much money. All help much appreciated,

Thanks - Ian

 

[Thermo]

if you have no option, then make sure that the materials you use have no frost in them before you start. The ground will not be frozen at the depth youre digging down to. Once the posts are in cover the top of the concrete back over with soil and it will protect it from the frost.

 

[vards01]

THanks for that, that is what I had planed on doing. I have been looking at using rapid cement mixed with ballast as oppose to std cement with accelerator additive and ballsast as its only about an extra £50 for the job. I was thinking of using a 10kg bag per post with 40kg (1:4)ballast, do you think thats sounds sufficient?

 

[vards01]

oh....I forgot to add, warm water as oppose to cold

 

[Thermo]

we always use normal cement in a dry mix, ram it in very well and then you can work with the posts. At the end of the day wet the mix in the holes with a bit more water.

dont use warm water

 

[vards01]

Was just reading Lafarge Extra Rapid Cement Datasheet and they advise using warm water in cold conditions, thats where I got this idea from? What so you do the whole days work with dry mix then pour water on top at the end of the day?

 

[gday2uk]

I think you are worrying too much.
Frost proofer is just that - to protect from frost. It would be used if you were laying a concrete slab etc.
Concrete for posts shouldn't finish at ground level and should be back filled with earth so not much chance of frost attacking it (unless really below freezing). Dry mix is fine considering how much rain we've had recently, it will soak up the water from surroundings. Rapid set could be a nightmare if you make a mistake...

 

[vards01]

So think a std cement on a semi dry mix + ballast with frost proofing additive will do the Job just fine? In 0oC

 

[Thermo]

if you want to waste money on frostproofer then go ahead!

 

[vards01]

I have some frostproofer left over from an old builing project which I was going to use.......

Thanks for the advice guys