I am building some raised borders using new sleepers and wondered if I need to line the inside of the sleepers with a non porous membrane to stop the sleepers from rotting before filling with soil, any help would be appreciated please?
We had sloping land behind our house levelled and retained with railway sleepers to make a potager with raised beds. The chap with the bulldozer and the sleeper muscles lined the insidesd of the wall, which is waist height in places, with black plastic sheeting to keep damp soil away from them and extend their lives.
16 years later, still there and doing their job as we intended.
Thanks, that's what I thought and seems like the sensible thing to do although I had wondered if the sleepers would rot if they were treated, will find out if my sleeper muscles are up to the job this weekend
We had a low retaining wall of sleepers put in around four years ago to hold a bank in place - the builder who did the work used new pressure treated sleepers and said they didn't need lining - we'll see ...........
If the sleepers are pressure treated they should last donkey's years without lining. However, pressure treatment is not an exact science and, like most things, can be good or bad quality.
If it were my wall I'd 'belt and brace' it, i.e. use pressure treated sleepers and fix a plastic liner on the retaining side too. Can't add much in terms of cost or time after all.
Mine are real ex railway sleepers so pressure treated and the rest to support trains and tracks. 15 to 18 years on and the external sides and tops have gradually weathered and are now showing open grain and growing moss and lichens in the shadier parts.
I would definitely advise belt and braces.
Pressure treated timber probably doesn't need anything to protect it, but it can't do any harm to line the inner surface with plastic sheeting or similar.