Jaques d'Alltrades wrote:

The message 1g49fl7.1v4xir1u4qrciN%00senetnospamtodayta@macun limited.net
from (Jim W) contains these words:

Gypsum (calcium sulphate, as opposed to 'lime' which is calcium
carbonate) is either sold as itself or by various 'brands' such as
claybreaker..

Slaked Lime = calcium hydroxide

Quicklime is calcium oxide.

Chalk is calcium carbonate.

--
Rusty Hinge

Ta muchly for that elucidation;-)

Jim

In article , TheScullster
writes
I intend to remove the blue/grey stuff which is very localised (about 1 sq
metre) and looks the most unhealthy.

I've been digging out a lot of the "pot clay" (yellow in our case) which
someone kindly dumped under our drawing room floor (don't ask!). It has
been dug up with a bricklayers trowel (not much room down there) and has
therefore come out in thin strips. I left these in a tub by a radiator
to dry, and found that they mix much more easily with compost in this
state than in big clumps. You can also put these dried pieces on a
concrete slab and run over them with a roller and reduce them to dust,
which can then be sprinkled over sandier parts of the garden (or you
could sew bags into your trouser legs and deposit it around the town).

John
--
John Rouse

In article , Jane Ransom
writes
But his/her bed is at a low point in the garden and he/she hasn't said
that there is anywhere to drain it to!!!!!!!!!!!!!!
It doesn't matter how much gravel or straw etc you add -

IT WON'T DRAIN IF IT IS THE LOWEST PART OF THE GARDEN (((((((((((

What he needs is a nice leylandii

John
--
John Rouse

In article , Steve
Harris writes

I sometimes wonder if I should add a little clay to my sand?

Perhaps we should have a "bring a truckload of soil" meet?

John
--
John Rouse

"John Rouse" wrote in message
...
In article , TheScullster
writes
I intend to remove the blue/grey stuff which is very localised (about 1
sq
metre) and looks the most unhealthy.

I've been digging out a lot of the "pot clay" (yellow in our case) which
someone kindly dumped under our drawing room floor (don't ask!).

My curiosity insists that I must ask.

[snip]

Franz

In article , Franz Heymann
writes

"John Rouse" wrote in message
...

I've been digging out a lot of the "pot clay" (yellow in our case) which
someone kindly dumped under our drawing room floor (don't ask!).

My curiosity insists that I must ask.

You may regret it. Our house is called "Springfield House" which should
have given any half-brained surveyor the clue that there were
underground watercourses in the area. It is built between two lines of
bassetting, and there is a lot of free water under the building. For
this reason the neighbours tree roots thought it would be an ideal place
to hang out, resulting in the building subsiding.

At some stage in the past, someone's answer to this problem (rather than
to clear out the stone drains around the cellar that were installed when
the house was built, and which drain into the main sewers) decided that
a better idea would be to fill the underfloor voids in the non-cellar
areas with rubble (including wood shavings, bricks and plaster) and then
cap the whole lot off with clay. Just for good measure they dumped pure
clay in places. In theory the plaster and wood shavings should have
broken down the clay into something quite nice, but without air or
organisms it doesn't quite happen like that.

Consequently I have been digging out some of the clay at the edges
(being careful not to get too near the footings - don't want them drying
out!) in order to try and improve the ventilation and reduce the damp.
--
John Rouse

"John Rouse" wrote in message
...
In article , Franz Heymann
writes

"John Rouse" wrote in message
...

I've been digging out a lot of the "pot clay" (yellow in our case)
which
someone kindly dumped under our drawing room floor (don't ask!).

My curiosity insists that I must ask.

You may regret it. Our house is called "Springfield House" which should
have given any half-brained surveyor the clue that there were
underground watercourses in the area. It is built between two lines of
bassetting, and there is a lot of free water under the building. For
this reason the neighbours tree roots thought it would be an ideal place
to hang out, resulting in the building subsiding.

At some stage in the past, someone's answer to this problem (rather than
to clear out the stone drains around the cellar that were installed when
the house was built, and which drain into the main sewers) decided that
a better idea would be to fill the underfloor voids in the non-cellar
areas with rubble (including wood shavings, bricks and plaster) and then
cap the whole lot off with clay. Just for good measure they dumped pure
clay in places. In theory the plaster and wood shavings should have
broken down the clay into something quite nice, but without air or
organisms it doesn't quite happen like that.

Consequently I have been digging out some of the clay at the edges
(being careful not to get too near the footings - don't want them drying
out!) in order to try and improve the ventilation and reduce the damp.

I am truly glad that I have never been landed in as bad a situation as that.
I hope you manage to sort it out satisfactorily.

Franz

John

I don't expect that ground water generally will be a problem.
Our house is almost at the top of a hill, so drainage of the garden
generally should be OK.
I am guardedly optimistic about being able to make something of the plot in
question.
As mentioned in the original post, the area has been covered - probably for
20 years - in plastic membrane, concrete etc. so there's been no opportunity
for the earth to breath or nutrients to be added.
If I can get 12-18" of workable material, with the top 12" being fair
quality, I'm hoping to make progress.

Phil

On Tue, 11 Nov 2003 12:57:08 +0000,
(Jim W) wrote:


Actually Gypsum is better and I believe is what you are thinking of,..
It will alter the pH in a similar way to lime but also helps the soil to
'crumb'

Sorry Jim, but gypsum is mildly acidic, while 'lime' (whether
carbonate*, oxide or hydroxide) is alkaline. Gypsum is the better
option for treating clay soil if you want to grow acid-loving plants
such as rhododendrons, azaleas etc. afterwards.

Much cheaper than Claybreaker is a bag or two of plaster from your
local builder's merchant or d-i-y store. Basically the same stuff and
does the same job.

*Some garden centres (our local Wyvale for example) sell ground
limestone (calcium carbonate) as 'lime', presumably on Health and
Safety grounds. Hydrated lime is quite caustic, while quicklime
(calcium oxide) is extremely so. Limestone will give the same results
as hydrated lime eventually, but it takes much longer because it's
less soluble.




--
Chris

E-mail: christopher[dot]hogg[at]virgin[dot]net

The message
from Chris Hogg contains these words:

Much cheaper than Claybreaker is a bag or two of plaster from your
local builder's merchant or d-i-y store. Basically the same stuff and
does the same job.

But in that case get sirapite (pink), not one of the
platerboard-covering (grey) ones.

--
Rusty Hinge
http://www.users.zetnet.co.uk/hi-fi/

"Chris Hogg" wrote in message
...
On Tue, 11 Nov 2003 12:57:08 +0000,
(Jim W) wrote:


Actually Gypsum is better and I believe is what you are thinking of,..
It will alter the pH in a similar way to lime but also helps the soil to
'crumb'

Sorry Jim, but gypsum is mildly acidic, while 'lime' (whether
carbonate*, oxide or hydroxide) is alkaline. Gypsum is the better
option for treating clay soil if you want to grow acid-loving plants
such as rhododendrons, azaleas etc. afterwards.

Much cheaper than Claybreaker is a bag or two of plaster from your
local builder's merchant or d-i-y store. Basically the same stuff and
does the same job.

But disperse it well, or mix it with plenty of dry soil before applying it,
otherwise it will set in large lumps when it gets wet.

[snip]

Franz

In article , TheScullster
writes
I don't expect that ground water generally will be a problem.
Our house is almost at the top of a hill, so drainage of the garden
generally should be OK.

Oh we're at the top of a hill, its just that the coal seams run at an
angle of about thirty degrees to the horizontal, and as our garden
slopes at about thirty degrees the other way, we have two, if not three,
coal seems bassetting in our plot.

I guess the good news is that we have somewhere for the water to drain
to.


John
--
John Rouse

The message
from John Rouse contains these words:
In article , TheScullster
writes

I don't expect that ground water generally will be a problem.
Our house is almost at the top of a hill, so drainage of the garden
generally should be OK.

Oh we're at the top of a hill, its just that the coal seams run at an
angle of about thirty degrees to the horizontal, and as our garden
slopes at about thirty degrees the other way, we have two, if not three,
coal seems bassetting in our plot.

I guess the good news is that we have somewhere for the water to drain
to.

And two, if not three drift mines?

--
Rusty Hinge
http://www.users.zetnet.co.uk/hi-fi/