I'm moving a small raised vegetable plot from the shady side of my
garden to the sunny side. It was installed by a previous occupant of
the house using old railway sleepers, which I've heard (on Gardeners'
World) contain harmful chemicals which leech into the soil and
vegetables. I was thinking of using scaffolding boards to support the
new bed but am fairly sure these too will contain preservatives. My
local timber merchant has recommended a cheaper alternative to
scaffolding boards but says without preservatives the wood would rot
in three years. The new preservatives they use are apparently free of
the copper, chrome and arsenic which made the old ones so hazardous.
Does anyone have any suggestions or advice please?

On 11 Apr 2007 09:47:22 -0700, wrote:
using old railway sleepers, which I've heard (on Gardeners'
World) contain harmful chemicals

creosote - phenols in coal,oil and wood tars and their extracts,
carsinogenic if not treated with care,
but ive not heard of any deformed carrots or carrot eaters!
A plastic membrane can be used to keep your veggies away from it.

I was thinking of using scaffolding boards to support the
new bed but am fairly sure these too will contain preservatives.

I think I remember GW/MontyD. using scaffold boards !
So they _must_ be ok ;-)

the wood would rot in three years.

"slabs" ( the trim from the sides of trees before serious planks are
sawn) as they are called by the sawmill are cheap and will survive for
several (many) years IF they are not buried, ie. if they have the
outside face exposed then here in SW English climate they are a cheap
and viable alternative,

The new preservatives they use are apparently free of
the copper, chrome and arsenic

Yes.

which made the old ones so hazardous.

Nope ! Not hazardous to your veggies nor to you from eating them.
Google on tanalising, you will find many trials, by those who had an
axe to grind, which set out to find leaching of those chemicals into
the soil and thence uptake in the plants. No reputable cases were
documented.

Consumption of sawdust by unmasked operatives or their children on diy
patios is a different matter
The result is that we now _nolonger_ have years of data to examine on
the longterm effects of the new approved substitutes of/for CCA
treatment in respect of the vegetable garden

Does anyone have any suggestions or advice please?

If in doubt use a barrier membrane, but be satisfied that that will
not be worse than percieved problem !


anti-coccidiosis anyone :-?(

Thanks for the advice WaltA.



On 11 Apr, 19:19, (WaltA) wrote:
On 11 Apr 2007 09:47:22 -0700, wrote:

using old railway sleepers, which I've heard (on Gardeners'
World) contain harmful chemicals

creosote - phenols in coal,oil and wood tars and their extracts,
carsinogenic if not treated with care,
but ive not heard of any deformed carrots or carrot eaters!
A plastic membrane can be used to keep your veggies away from it.

I was thinking of using scaffolding boards to support the
new bed but am fairly sure these too will contain preservatives.

I think I remember GW/MontyD. using scaffold boards !
So they _must_ be ok ;-)

the wood would rot in three years.

"slabs" ( the trim from the sides of trees before serious planks are
sawn) as they are called by the sawmill are cheap and will survive for
several (many) years IF they are not buried, ie. if they have the
outside face exposed then here in SW English climate they are a cheap
and viable alternative,

The new preservatives they use are apparently free of
the copper, chrome and arsenic

Yes.

which made the old ones so hazardous.

Nope ! Not hazardous to your veggies nor to you from eating them.
Google on tanalising, you will find many trials, by those who had an
axe to grind, which set out to find leaching of those chemicals into
the soil and thence uptake in the plants. No reputable cases were
documented.

Consumption of sawdust by unmasked operatives or their children on diy
patios is a different matter
The result is that we now _nolonger_ have years of data to examine on
the longterm effects of the new approved substitutes of/for CCA
treatment in respect of the vegetable garden

Does anyone have any suggestions or advice please?

If in doubt use a barrier membrane, but be satisfied that that will
not be worse than percieved problem !

anti-coccidiosis anyone :-?(

wrote:

I'm moving a small raised vegetable plot from the shady side of my
garden to the sunny side. It was installed by a previous occupant of
the house using old railway sleepers, which I've heard (on Gardeners'
World) contain harmful chemicals which leech into the soil and
vegetables. I was thinking of using scaffolding boards to support the
new bed but am fairly sure these too will contain preservatives. My
local timber merchant has recommended a cheaper alternative to
scaffolding boards but says without preservatives the wood would rot
in three years. The new preservatives they use are apparently free of
the copper, chrome and arsenic which made the old ones so hazardous.
Does anyone have any suggestions or advice please?

Not exactly the cheap option but you can buy untreated sleepers. I bought a
couple to use as the base of my greenhouse. They will rot, but being 12" x
6" it'll take a very long time before it becomes a significant problem,
even in the GH. I've had mine for close to 10 years now, and they are
still going strong. Oh you also need to call in help to move them since
they do weigh rather a lot.
Duncan