Using Postcrete

[billy bookcase]

I need to replace some broken fence-posts
installed insufficiently deep, given the
ease of digging them out, by a previous
occupant. I have a fence post augur which
can easily go down two feet with a long
bar to dislodge stones etc. Postcrete has
been suggested in addition.

Looking at the (laughable) videos the theory
of Postcrete seems to be digging a really wide
hole filling it half with water with the post
positioned pouring in the Postcrete and forming
a wide round Postcrete slab at the bottom of the
hole into which the post is held upright for 10
ins until it sets. After which the hole is
backfield.

So totally unsuitable for use with neat holes
made with a post hole augur presumably.


bb

[Tricky Dicky]

Most professional fence installs I have seen the post holes have been deep rather than wide. Filling wide holes with postcrete is going to be very expensive. If you are erecting timber posts then I would simply use postcrete for what it is good at namely fast setting to get your posts situated quickly. If the posts are going into soil I would then add further normal concrete using perhaps forms to neatly raise the concrete level above the soil as it is at air/soil interface that rot appears.

Richard

[newshound]

Personally I would auger the hole to two feet, put in a couple of inches
of dry postcrete at the bottom, put in the post and hold it centred
before adding more dry postcrete around it, compacting it as well as
possible with something like a length of rebar, tamp it down thoroughly
with a lump hammer and block of wood when the postcrete reaches the
surface (topping up as necessary), and *then* add water.

[alan_m]

On 28/02/2022 11:39, billy bookcase wrote:

What be your method of securing a post into an auger hole? It cannot be
by pouring in some concrete because you seem to have already dismissed
the equivalent method using postcrete.

In my experience postcrete does work well with post holes only 3 to 4
inches wider (on all sides) than a post. Using postcrete doesn't stop
the use of broken brick etc. to wedge the post in place before adding
the postcrete. The water can also be added after the dry postcrete has
been added to the hole and then tamped down with something like an iron
bar, which also puts holes in the postcrete to allow the top applied
water to penetrate.

It seen a lot of fencing companies use postcrete because it allows them
to build the fence in the sequence install post, install gravel board,
dig hole for next post, install panel, install post....... The quick
setting of the postcrete means that the posts are stable within a very
short time.




--
mailto : news {at} admac {dot} myzen {dot} co {dot} uk

[John Rumm]

On 28/02/2022 11:39, billy bookcase wrote:

Last time I used it was with neat holes dug with a post hole tool and a
graft:

http://wiki.diyfaq.org.uk/index.php/File:PPFencePostHoles.jpg

The holes were 2' deep. I placed a bit of broken slab in the bottom so
that the post was not in contact with soil, half filled with water, and
poured in a bag of postcrete. Added a little more water of required, and
then tamped it with a length of timber. Made sure the post was held
upright and let it go off. I then flaunched up the top with some
additional (ordinary) concrete once the postcrete was set.


--
Cheers,

John.

/=================================================================\
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[billy bookcase]

"John Rumm" <see.my.s...@nowhere.null> wrote in message
news:sviggg$aqt$1...@dont-email.me...

> The holes were 2' deep. I placed a bit of broken slab in the bottom so that the post
> was not in contact with soil, half filled with water, and poured in a bag of postcrete.
> Added a little more water of required, and then tamped it with a length of timber.

Thanks for the explanation,

You followed the standard method of pouring in the water then
the postcrete. Newshound and posters on other sites suggest
pouring in dry postcrete and then adding water.

What I'm wondering is why it isn't possible to mix the postcrete in a
bucket and pour that in, tamping down as you go ? Obviously exact
ratios would need to determined beforehand using paper cups
etc, But that isn't mentioned anywhere. Ten minutes drying
time would seem more than sufficient for this

I need to keep the holes as narrow as possible in order to avoid
disturbing established plants either in terms off having to dig
them out or causing too much root damage


bb

[Chris Green]

Chris Hogg <m...@privacy.net> wrote:
[snip various bits of good advice]
>
> Concrete posts don't rot, or, cheaper, concrete repair spurs, which
> allow you to use the uppers of old timber posts that haven't rotted.
> https://tinyurl.com/y8ydklh6
>
Wooden posts generally work better (in terms of longevity) *without*
any concrete. We have 9 acres of land divided up for grazing with
electric tape on wooden posts. I thus have a fairly steady job of
replacing the posts if/when they fail and learn what works and what
doesn't work.

I have *some* posts which were originally knocked into the ground more
than 20 years ago and, when I moved them just recently, were still
very sound. These were not machined round ones, they were simpler
'stripped bark' ones, not beautiful but certainly effective!

--
Chris Green
·

[The Natural Philosopher]

On 28/02/2022 11:53, Tricky Dicky wrote:
> Most professional fence installs I have seen the post holes have been
> deep rather than wide.

I put in some garden posts some years back using various grades of
pressure treated timber straight into DEEP holes (dug slowly with a
garden TROWEL to about 1.5m). Holes then backfilled and tamped down HARD.

They will last as long as the pressure treating does and postcrete would
not have improved them.

Some of them with less well treated quarter round timber have simply
rotted below ground level

I cant see that except in the case of very slender posts with no lateral
area to resist being pushed over, that encasing in concrete adds
anything much at all. Its a quick (and expensive) way to e,g use a
digger to make a bloody great hole and not bother to back fill it



--
A lie can travel halfway around the world while the truth is putting on
its shoes.

[The Natural Philosopher]

Yes, its a low labour high cost way to do it. You gain very little
stability and i am of the opinion that encasing wood in a concrete
sheath doesn't stop it rotting at all - there is so to speak no damp
proof course, and water will wick through the concrete and up the post
and rot at the base no matter what.

Advice I was given years ago and experience shows that a good treated
timber post is fine in bare soil.

A badly/un- treated post will rot no matter what.




>
>


--
Climate is what you expect but weather is what you get.
Mark Twain

[Peter Johnson]

On Mon, 28 Feb 2022 11:39:22 -0000, "billy bookcase" <bi...@anon.com>
wrote:

Presumably the people who make videos don't own an auger.

[Another John]

In article <sviimr$sjc$1...@dont-email.me>,

"billy bookcase" <bi...@anon.com> wrote:

> "John Rumm" <see.my.s...@nowhere.null> wrote in message
> news:sviggg$aqt$1...@dont-email.me...
> > The holes were 2' deep. I placed a bit of broken slab in the bottom so that
> > the post
> > was not in contact with soil, half filled with water, and poured in a bag
> > of postcrete.
> > Added a little more water of required, and then tamped it with a length of
> > timber.
>
> Thanks for the explanation,
>
> You followed the standard method of pouring in the water then
> the postcrete. Newshound and posters on other sites suggest
> pouring in dry postcrete and then adding water.

That's wrong - ask Postcrete, Inc!

>
> What I'm wondering is why it isn't possible to mix the postcrete in a
> bucket and pour that in, tamping down as you go ? Obviously exact
> ratios would need to determined beforehand using paper cups
> etc, But that isn't mentioned anywhere. Ten minutes drying
> time would seem more than sufficient for this

By the time you've mixed it, it will be half-set!

> I need to keep the holes as narrow as possible in order to avoid
> disturbing established plants either in terms off having to dig
> them out or causing too much root damage

Postcrete is brilliant, imho, in certain situations. But if I had your
2' augur (and, infinitely more important, your evident strength!) I'd
use properly treated posts, a stone in the bottom to encourage drainage,
and then just 1" inch gravel, tamped hard (as TNP has mentioned).
Needless to say, you need to centre, and square, and level, the posts
precisely -- but you absolutely have to do that with Postcrete anyway
(at least you can just about extract gravel, before it's tamped too
hard, if things go pear-shaped.

As John Rumm said, I'd finish off the top few inches with 'flaunching',
to cast rainwater away from the hole. You could use Postcrete for that,
as long as you work quick and neat! :-)

Good luck! Take your time, mind!

John

[Tim Lamb]

In message <svikdt$afk$1...@dont-email.me>, The Natural Philosopher
<t...@invalid.invalid> writes

Oak lasts well. Better with a bit of rot proofing.
The post and rail fencing to our by-pass is still sound after 45 years!
Although a bit degraded by Sunlight. I have mentioned the preservative
in here before.. smells of Mothballs and makes the wood non-flammable.
For field strainer posts I would use a mix of rubble and small stones.
Intermediate posts sledge hammered into a hole opened up with a crowbar.

--
Tim Lamb

[Adam Funk]

On 2022-02-28, billy bookcase wrote:

>
> "John Rumm" <see.my.s...@nowhere.null> wrote in message
> news:sviggg$aqt$1...@dont-email.me...
>> The holes were 2' deep. I placed a bit of broken slab in the bottom so that the post
>> was not in contact with soil, half filled with water, and poured in a bag of postcrete.
>> Added a little more water of required, and then tamped it with a length of timber.
>
> Thanks for the explanation,
>
> You followed the standard method of pouring in the water then
> the postcrete. Newshound and posters on other sites suggest
> pouring in dry postcrete and then adding water.

Maybe they've changed the instructions, but when I used it about 15
years ago, I put the post in place, poured the dry mix around it,
propped the post up plumb and then used a watering can to gently pour
water into the mix.

[billy bookcase]

"Another John" <lal...@hotmail.com> wrote in message
news:lalaw44-7A05B2...@201-92-171-81.dsl.telesp.net.br...

>
> Postcrete is brilliant, imho, in certain situations. But if I had your
> 2' augur (and, infinitely more important, your evident strength!)

The 4"dia augur "could" go down to 3ft although your knuckles would
be scraping the ground. The trick is to only turn it once or twice,
pull it out, and scrape off all the soil, and then go again. It was
bought years ago for round posts. These are 4in sq. You do need a
long bar however to clear any obstructions it meets on the way.

This is just to keep the neighbours happy basically, without spending
a fortune on it. Rather than it lasting 50 years.


bb

[alan_m]

On 28/02/2022 16:11, Tim Lamb wrote:

> Oak lasts well. Better with a bit of rot proofing.

The oak posts I dug out of my parents garden years ago were around 50
years old. Judging by what came out they were just placed in a hole and
back-filled with earth BUT the bit underground was tapered. The width of
the post at the bottom of the hole was approx twice that of the width at
the ground level.

[John Rumm]

On 28/02/2022 13:29, billy bookcase wrote:
> "John Rumm" <see.my.s...@nowhere.null> wrote in message
> news:sviggg$aqt$1...@dont-email.me...
>> The holes were 2' deep. I placed a bit of broken slab in the bottom so that the post
>> was not in contact with soil, half filled with water, and poured in a bag of postcrete.
>> Added a little more water of required, and then tamped it with a length of timber.
>
> Thanks for the explanation,
>
> You followed the standard method of pouring in the water then
> the postcrete. Newshound and posters on other sites suggest
> pouring in dry postcrete and then adding water.

It will probably work, but you may not hydrate all of the mix as well.
Its a non critical application, so it will not make much difference in
practice - so long as it sets it is not going to matter if it achieves
full strength.

> What I'm wondering is why it isn't possible to mix the postcrete in a
> bucket and pour that in, tamping down as you go ? Obviously exact
> ratios would need to determined beforehand using paper cups
> etc, But that isn't mentioned anywhere. Ten minutes drying
> time would seem more than sufficient for this

It is, but the whole idea is to make it very simple. No pre-mixing
required - stick a hose in the hole for a bit, or chuck a bucket of
water in, empty in the bag of dry mix (which is hence lighter and easier
to handle), quick prod with a stick, make sure the post is upright, and
then leave it to do its thing.

> I need to keep the holes as narrow as possible in order to avoid
> disturbing established plants either in terms off having to dig
> them out or causing too much root damage

As you can see from the photo, my holes were only about 6 inchs wide
with a 4" post.

[John Rumm]

On 28/02/2022 15:03, Another John wrote:

> As John Rumm said, I'd finish off the top few inches with 'flaunching',
> to cast rainwater away from the hole. You could use Postcrete for that,
> as long as you work quick and neat! :-)

I found with a 24" hole, there was not quite enough in one bag to fill
it to a level where you could do the flaunching (which really needs to
be just above ground level), so doing all the flaunching in one hit
later was easier.

[Brian]

Used correctly, it seems to work fine. I had some fence posts and panels
replaced after a previous storm, they survived the latest one. We lost some
other panels etc but the posts repaired with postcrete are fine.

[newshound]

On 28/02/2022 17:50, John Rumm wrote:
> On 28/02/2022 13:29, billy bookcase wrote:
>> "John Rumm" <see.my.s...@nowhere.null> wrote in message
>> news:sviggg$aqt$1...@dont-email.me...
>>> The holes were 2' deep. I placed a bit of broken slab in the bottom
>>> so that the post
>>> was not in contact with soil, half filled with water, and poured in a
>>> bag of postcrete.
>>> Added a little more water of required, and then tamped it with a
>>> length of timber.
>>
>> Thanks for the explanation,
>>
>> You followed the standard method of pouring in the water then
>> the postcrete. Newshound and posters on other sites suggest
>> pouring in dry postcrete and then adding water.
>
> It will probably work, but you may not hydrate all of the mix as well.
> Its a non critical application, so it will not make much difference in
> practice - so long as it sets it is not going to matter if it achieves
> full strength.
>

Even dry bits are going to hydrate from the ground pretty quickly!

[Brian]

John Rumm <see.my.s...@nowhere.null> wrote:
> On 28/02/2022 13:29, billy bookcase wrote:
>> "John Rumm" <see.my.s...@nowhere.null> wrote in message
>> news:sviggg$aqt$1...@dont-email.me...
>>> The holes were 2' deep. I placed a bit of broken slab in the bottom so that the post
>>> was not in contact with soil, half filled with water, and poured in a bag of postcrete.
>>> Added a little more water of required, and then tamped it with a length of timber.
>>
>> Thanks for the explanation,
>>
>> You followed the standard method of pouring in the water then
>> the postcrete. Newshound and posters on other sites suggest
>> pouring in dry postcrete and then adding water.
>

We used a local company to repair a fence several years back. They used
postcrete. They certainly filled the hole with water and added the mix. The
posts stood up to the recent storm. ;-)

[wasbit]

"The Natural Philosopher" <t...@invalid.invalid> wrote in message
news:svikdt$afk$1...@dont-email.me...

> On 28/02/2022 12:46, alan_m wrote:
>> On 28/02/2022 11:39, billy bookcase wrote:
>>>

> snip <

> Advice I was given years ago and experience shows that a good
> treated timber post is fine in bare soil.
>
> A badly/un- treated post will rot no matter what.
>
>

That's what post savers are for
- https://www.postsaver.com/

--
Regards
wasbit

[wasbit]

"Adam Funk" <a24...@ducksburg.com> wrote in message
news:9iaveix...@news.ducksburg.com...

> On 2022-02-28, billy bookcase wrote:
>
>>
>> "John Rumm" <see.my.s...@nowhere.null> wrote in message
>> news:sviggg$aqt$1...@dont-email.me...
>>> The holes were 2' deep. I placed a bit of broken slab in the bottom so
>>> that the post
>>> was not in contact with soil, half filled with water, and poured in a
>>> bag of postcrete.
>>> Added a little more water of required, and then tamped it with a length
>>> of timber.
>>
>> Thanks for the explanation,
>>
>> You followed the standard method of pouring in the water then
>> the postcrete. Newshound and posters on other sites suggest
>> pouring in dry postcrete and then adding water.
>
> Maybe they've changed the instructions, but when I used it about 15
> years ago, I put the post in place, poured the dry mix around it,
> propped the post up plumb and then used a watering can to gently pour
> water into the mix.
>
>

Then agitate with a stick.
Instructions on the bag say water first, then postcrete followed by more
water & agitate.

--
Regards
wasbit

[wasbit]

"Peter Johnson" <pe...@parksidewood.nospam> wrote in message
news:g3op1hleb31tgus9i...@4ax.com...

Presumably the people who make videos have nice soft ground to dig holes in.
Try digging holes in brash - that's layers of stone.

--
Regards
wasbit

[fred]

We had to do that with an engine driven post hole borer. It was still a nightmare as the borer kept kicking back when it contacted a stone. Took two of us to manage it

[Roger Mills]

On 28/02/2022 13:29, billy bookcase wrote:

>

> What I'm wondering is why it isn't possible to mix the postcrete in a
> bucket and pour that in, tamping down as you go ? Obviously exact
> ratios would need to determined beforehand using paper cups
> etc, But that isn't mentioned anywhere. Ten minutes drying
> time would seem more than sufficient for this
>

BAD IDEA! It goes off too quickly. It sets solid in 10 minutes, but
becomes unworkable much sooner than that.
--
Cheers,
Roger