Raised beds

Sounds fabby. I trust your camera is ready and loaded with digital film to record the construction? 

There is much talk about the problems, or supposed problems of using old, used, sleepers that might be oozing tar and such like.

From my own practical experience of the last 5 years of having a raised bed and a green house sat on a foundation of such sleepers I can report that I have had no problems of any kind at any time.

the sleepers that the green house is screwed down on where lined with pond liner type material on the top and inside, the raised bed is in its birthday suit.

PS on a hot day with the temp up to 30'C there is no smell of tar or creosote in the green house.