Coarse Sand or Grit for clay soils
 

I have an allotment with a very clay soil. Plenty of muck and compost
helps but I believe that I need to add some coarse grit or sand to help
break it up. Horticultural sand is quite expensive so can I use builders
sand or is it treated with chemicals that would harm my soil and
vegetables? Or has anyone got any other suggestions?

In article ,
bruce writes:
|
| I have an allotment with a very clay soil. Plenty of muck and compost
| helps but I believe that I need to add some coarse grit or sand to help
| break it up. Horticultural sand is quite expensive so can I use builders
| sand or is it treated with chemicals that would harm my soil and
| vegetables? Or has anyone got any other suggestions?

Don't use builder's sand! But do use sharp sand from a builder's
merchant. No, it's not treated with chemicals.


Regards,
Nick Maclaren.

Nick Maclaren muttered:

Don't use builder's sand! But do use sharp sand from a builder's
merchant. No, it's not treated with chemicals.

We were quite lucky with the tons of 'topsoil' we had delivered... as
topsoil it was rubbish, they'd mixed in 50:50 with a load of sand to bulk it
out. However it was ideal for the clay and builders' rubble we spread it on
for our lawn, which, 2 years later, looks great.

Do the standard thing-add calcium. Lime for vegetables, chalk if you've got
growing plants or fresh fertiliser in the ground or gypsum if you need to
maintain acidity.
2ozs/square yard of lime a little more chalk-I reckon about 4ozs for gypsum
although I've never used it.
Calcium ions cause edge to edge flocculation in the clay and make it form a
crumb rather than a slimy plastic structure.
David T

"Nick Maclaren" wrote in message
...

In article ,
bruce writes:
|
| I have an allotment with a very clay soil. Plenty of muck and compost
| helps but I believe that I need to add some coarse grit or sand to
help
| break it up. Horticultural sand is quite expensive so can I use
builders
| sand or is it treated with chemicals that would harm my soil and
| vegetables? Or has anyone got any other suggestions?

Don't use builder's sand! But do use sharp sand from a builder's
merchant. No, it's not treated with chemicals.


Regards,
Nick Maclaren.

david taylor wrote:
Do the standard thing-add calcium. Lime for vegetables, chalk if you've got
growing plants or fresh fertiliser in the ground or gypsum if you need to
maintain acidity.
2ozs/square yard of lime a little more chalk-I reckon about 4ozs for gypsum
although I've never used it.
Calcium ions cause edge to edge flocculation in the clay and make it form a
crumb rather than a slimy plastic structure.
David T

"Nick Maclaren" wrote in message
...

In article ,
bruce writes:
|
| I have an allotment with a very clay soil. Plenty of muck and compost
| helps but I believe that I need to add some coarse grit or sand to
help
| break it up. Horticultural sand is quite expensive so can I use
builders
| sand or is it treated with chemicals that would harm my soil and
| vegetables? Or has anyone got any other suggestions?

Don't use builder's sand! But do use sharp sand from a builder's
merchant. No, it's not treated with chemicals.


Regards,
Nick Maclaren.



That was an excellently rapid response...
I do use lime - should have said. But I don't want to overdo it and make
my soil too alkaline, so I usually reserve it for when I'm planting
brassica. Where do I get gypsum from - I don't recall seeing it anywhere?
I didn't appreciate builders sand and sharp sand were different products
- will a builder's merchant know the difference?

"bruce" wrote in message
...
david taylor wrote:
Do the standard thing-add calcium. Lime for vegetables, chalk if you've
got
growing plants or fresh fertiliser in the ground or gypsum if you need
to
maintain acidity.
2ozs/square yard of lime a little more chalk-I reckon about 4ozs for
gypsum
although I've never used it.
Calcium ions cause edge to edge flocculation in the clay and make it
form a
crumb rather than a slimy plastic structure.
David T

"Nick Maclaren" wrote in message
...

In article ,
bruce writes:
|
| I have an allotment with a very clay soil. Plenty of muck and compost
| helps but I believe that I need to add some coarse grit or sand to
help
| break it up. Horticultural sand is quite expensive so can I use
builders
| sand or is it treated with chemicals that would harm my soil and
| vegetables? Or has anyone got any other suggestions?

Don't use builder's sand! But do use sharp sand from a builder's
merchant. No, it's not treated with chemicals.


Regards,
Nick Maclaren.



That was an excellently rapid response...
I do use lime - should have said. But I don't want to overdo it and make
my soil too alkaline, so I usually reserve it for when I'm planting
brassica. Where do I get gypsum from - I don't recall seeing it anywhere?
I didn't appreciate builders sand and sharp sand were different products
- will a builder's merchant know the difference?

Sharp sand is gritty to the touch, the grains are angular, in my neck of the
woods it is
a light grey colour. Builder's sand is also known as soft sand and is
usually a golden
colour, soft to the touch, staining your fingers yellow, and made up of many
different
sizes of rounded particle, down to clay size. It is good for bricklaying and
mortar.

Andy.

And thanks Andy, I missed you off my last post.

david taylor wrote:
Do the standard thing-add calcium. Lime for vegetables, chalk if you've got
growing plants or fresh fertiliser in the ground or gypsum if you need to
maintain acidity.
2ozs/square yard of lime a little more chalk-I reckon about 4ozs for gypsum
although I've never used it.
Calcium ions cause edge to edge flocculation in the clay and make it form a
crumb rather than a slimy plastic structure.
David T

"Nick Maclaren" wrote in message
...

In article ,
bruce writes:
|
| I have an allotment with a very clay soil. Plenty of muck and compost
| helps but I believe that I need to add some coarse grit or sand to
help
| break it up. Horticultural sand is quite expensive so can I use
builders
| sand or is it treated with chemicals that would harm my soil and
| vegetables? Or has anyone got any other suggestions?

Don't use builder's sand! But do use sharp sand from a builder's
merchant. No, it's not treated with chemicals.


Regards,
Nick Maclaren.

"bruce" wrote in message
...
I have an allotment with a very clay soil. Plenty of muck and compost helps
but I believe that I need to add some coarse grit or sand to help break it
up. Horticultural sand is quite expensive so can I use builders sand or is
it treated with chemicals that would harm my soil and vegetables? Or has
anyone got any other suggestions?



if u can get it gypsum is the best thing and its relatively cheap

I live next to an old abandoned football pitch which me and the neighbours have been sneakily turning into a wildflower meadow / birch grove over the last few years. Whenever I need grit, I just go out and dig up a bucket of 'blaze', but it occurred to me the other day that I have no idea what 'blaze' actually is! Does anyone know the origins of the scrapy red granular stuff? And why is it called blaze? Is it because when you fall over on it, it feels like someone has burned off your outer layers of skin??

Bob

In article ,
Janet Baraclough wrote:
The message
from undergroundbob contains
these words:

I live next to an old abandoned football pitch which me and the
neighbours have been sneakily turning into a wildflower meadow / birch
grove over the last few years. Whenever I need grit, I just go out and
dig up a bucket of 'blaze', but it occurred to me the other day that I
have no idea what 'blaze' actually is! Does anyone know the origins of
the scrapy red granular stuff? And why is it called blaze? Is it
because when you fall over on it, it feels like someone has burned off
your outer layers of skin??

I always thought it was crushed-up recycled bricks, and that
accounted for its injurious nature :-( But I'm sure cormaic's website
will have the proper answer. www.pavingexpert.com/

Tiles, perhaps, but almost all bricks are soft (by stone standards)
and blaze clearly is not.


Regards,
Nick Maclaren.

andrewpreece wrote:
Sharp sand is gritty to the touch, the grains are angular, in my neck of
the woods it is a light grey colour. Builder's sand is also known as soft
sand and is usually a golden colour, soft to the touch, staining your
fingers yellow, and made up of many different sizes of rounded particle,
down to clay size. It is good for bricklaying and mortar.

Am I right in thinking that sharp sand is mostly quartz with similar grain
size (from aeolian or water deposits - think sandy beach) whilst builder's
sand is mechanically ground up rock (of any provenance) with a large
proportion of feldspar minerals which will get hydrated to clays in short
order? So in other words you're just adding more clay?

Theo

Don't use sand it will mix with the fine clay and make cement and ruin
your good soil. Continue with organic matter.

Derryl


I have an allotment with a very clay soil. Plenty of muck and compost
helps but I believe that I need to add some coarse grit or sand to help
break it up. Horticultural sand is quite expensive so can I use builders
sand or is it treated with chemicals that would harm my soil and
vegetables? Or has anyone got any other suggestions?

On 28 Apr 2005 16:54:13 +0100 (BST), Theo Markettos
wrote:

andrewpreece wrote:
Sharp sand is gritty to the touch, the grains are angular, in my neck of
the woods it is a light grey colour. Builder's sand is also known as soft
sand and is usually a golden colour, soft to the touch, staining your
fingers yellow, and made up of many different sizes of rounded particle,
down to clay size. It is good for bricklaying and mortar.

Am I right in thinking that sharp sand is mostly quartz with similar grain
size (from aeolian or water deposits - think sandy beach) whilst builder's
sand is mechanically ground up rock (of any provenance) with a large
proportion of feldspar minerals which will get hydrated to clays in short
order? So in other words you're just adding more clay?

Theo

Sharp sand and builder's sand are both just natural sands from
whatever source, usually quartz as you suggest, washed and sieved to
the appropriate sizes where required.

The finer you crush rock, the more energy it takes and the more
expensive it gets. Making builder's sand that way would be very
expensive. Certainly, rock crushing to make roadstone or aggregates
for concrete generates some fine stuff, but not nearly enough for the
building industry.

Sharp sand is made up of angular grains, as Andrew says, while aeolian
sands tend to have rounded grains. In SW England, we have squillions
of tons of angular-grained sand available as a by-product from the
china clay industry. Mostly quartz, some feldspar, light grey to white
in colour. Washed and graded to the appropriate sizes, it makes
excellent quality sands for all purposes and is widely used. I get
what he calls 3 mm (actually about 1 - 5 mm) from a local sand and
aggregate merchant, approx GBP25 delivered for a 'dumpy bag', about a
ton I guess.

Feldspar minerals do convert to clays, but only over a great many
millions of years!


--
Chris

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

Chris Hogg wrote:
[...]
The finer you crush rock, the more energy it takes and the more
expensive it gets. Making builder's sand that way would be very
expensive. Certainly, rock crushing to make roadstone or aggregates
for concrete generates some fine stuff, but not nearly enough for
the
building industry.
[...]

On a point of information, last time I had the builders in big-time,
in '88, at one point their suppliers did run out of ordinary sand,
and did send "artificial" sand from crushed rock. I, too, thought of
the cost, but at that stage it wasn't worryingly more expensive than
natural sand; though it doesn't sound a sustainable technique, I
agree. As always, perhaps it's a question of balancing transport
costs for any given location against production costs at a given
source.

--
Mike.

Janet Baraclough wrote:
The message
from Derryl contains these words:

Don't use sand it will mix with the fine clay and make cement and ruin
your good soil.

No, it won't. Not in the UK, where Theo is posting from.

Indeed (though Derryl wasn't replying to my post). There isn't enough
calcium content, and any reactive material that has been exposed to the
elements will already have been hydrated so won't be able to undergo the
hydration reactions that set cement.

Cementation will eventually happen with a calcitic pore fluid crystallising
around the grains but this is likely to happen under pressure once buried
and over thousands of years, so not a problem for most gardeners.

Theo