[Goldcraig]

I have aquired a load of sleepers for making raised beds, due to clay soil. They have been treated with creosote. Will I have to wrap them with polythene, or other material to stop soil contamination from the ceosote?
I am under the impression that it wil seep intp the soil and kill anything growing in it....hope I'm wrong....

[lachlanandmarcus]

Yes is the short answer, they are not allowed to be sold for that purpose anymore, so if you use them for veggies, make sure there is some impermeable layer between them and the veggies. Having said that Ive not seen them killing veggies, at least not in decent sized beds (like 4m x 2m), maybe it would be more of an issue in a mini bed where they were very close to the crops.

[Bangbang]

I was looking on Ebay last night for timber, and in my search there are several suppliers
of untreated sleepers 10" x 4".
 

[Lesley Silvester]

I always use untreated wood for my raised beds.  It doesn't last as long but I know nothing nasty is going to be in my food.  I read about tannalised wood in Garden Organic magazine a few years back.  Some had been used to a children's palyground and it was discovered that arsenic had leached into the soil.  Scary.