Some postcrete questions (thermo?)

[andytx]

Hi all,

I'm in the process of digging out some 30 year old 8' leylandii, removing an old wood fence and replacing it with larchlap panels and concrete posts. Back-breaking!

8' posts, 2' hole dug narrow and deep, then using postcrete. Postcrete has been going in dry (~1.5 bags per hole), tamped down well, then added water. Few questions:

1. How can I be sure that the water has penetrated the whole hole (pun intended!), the full 2 feet? and not left some dry mix at the bottom of the hole.

2. Is it possible to add too much water, and adversely affect the postcrete? I've added most of a bucket, which has left a good covering of water over the surface of the postcrete. When I return later, the first inch or so of concrete has not gone off (it's soft) - but under this it seems fine (and the posts seem solid enough). This top layer never goes off.

Thanks in advance...

Andy

 

[WabbitPoo]

The bottom will go off from moisture in the soil anyway (eventually). The top bit has had too much water. Unless the soft bit is very deep then dont worry

 

[andytx]

The bottom will go off from moisture in the soil anyway (eventually). The top bit has had too much water. Unless the soft bit is very deep then dont worry

Thanks for that, bit of reassurance!

I'm a little undecided about what to do on the next post, either water first or postcrete first. Will probably continue with the postcrete first (bit less water!), other than my concerns about the soft bit at the top - it seems to be the best way to work.

Bought a couple of bags of the Wickes (blue circle) stuff. Wasn't impressed by the lack of aggregate, so mixed it with my other postcrete (a "tarmac" product). Not sure if mixing brands is a good idea, but it got rid of the blue circle bags.

ps. Hats off to anybody who does this for a living, ripping out leylandii, an old fence then digging post holes and creating a new fence is doing me in! back-breaking work...

Andy

 

[Thermo]

yep the blue circle stuff is not good. easiest way to do it is work with it dry and ram it all in. When you have finished the days work then wet them. they will never go off hard enough o work with without moving them if you do it at the time. all the time its dry it will stay firm and you also have the option of making any adjustments with it.

 

[Kevstir]

we have just finished putting decking down with the joists set on wooden posts, we used hanson postmix for 3/4 of the posts and the stuff was crap tbh took ages to set and you had to be precise with the amount of water you added, the last 12 posts we used blue circle postcrete and that stuff was/is sooo much better, did think for a min about it not having big bits of aggregate but soon didn't bother when i realised how good it was compared to the hanson stuff with loads of aggregate, just half fill the hole with water and pour the postcrete in , add a little bit more water on top if needed and 10/15mins later its solid, will be using this stuff from now on, well worth the extra 90p a bag.

 

[WabbitPoo]

Course, you COULD save money by mixing your own - make it damp, and ram it in. Next morning, its hard.

 

[andytx]

we used hanson postmix for 3/4 of the posts and the stuff was crap tbh took ages to set and you had to be precise with the amount of water you added, the last 12 posts we used blue circle postcrete and that stuff was/is sooo much better, did think for a min about it not having big bits of aggregate but soon didn't bother when i realised how good it was compared to the hanson stuff with loads of aggregate, just half fill the hole with water and pour the postcrete in , add a little bit more water on top if needed and 10/15mins later its solid, will be using this stuff from now on, well worth the extra 90p a bag.

Aha! someone with a simillar experience...

Anybody got any thoughts about mixing the blue circle postcrete with another postcrete with aggregate? I sort of did this, but in hindsight I used far too much water.

Is mixing postcretes asking for trouble?

Andy

 

[JohnD]

concrete posts.

Very wise choice.

 

[andytx]

concrete posts.

Very wise choice.

Quite funny really. The fence is a boundry fence between us and a neighbour, and they're paying half (the materials). Neighbours wanted wood for looks, but I wanted concrete for longevity. The concrete posts I ordered arrived, and are rough on one side. We (wife and I) discussed at length who should get the "good" side, and who the "bad". We decided to surreptitiously give them the rough side, and just get them concreted in before anybody noticed.

Imagine my joy at our 8 year old shouting across the garden "are we getting the good side?" as I was laying them. Still, we're not home and dry yet as I'm not finished...

Andy

 

[JohnD]

concrete posts are naturally beautiful, but if you want to make them absolutely stunning, you can use masonry paint to make them blend in with the preservative stain on the timber.

Ignore Thermo on this subject. He has no sense of aesthetics and has an unheathy obsession with gnomes.

View media item 975

 

[Thermo]

go back to the blue circle home for the mentally disturbed and finish painting your concrete toadstools

 

[springdingo]

I'm with Kevstir on this one. Fill hole 1/3 full with water, add postcrete, add extra water on top. Stays workable just long enough to slope away from post. I use the LeFarge stuff from Wickes, I guess the lack of aggregate is because it doesn't need much strength, it's contained on all sides.

My only problem is finding out how big to dig the hole for a 3m post?