Raised beds using sleepers are a really straightforward thing to build. The most complicated thing is lugging big lumps of wood about! Here is a raised bed job we’ve done using new oak sleepers. Oak is, of course, an incredibly hard-wearing wood. There are different types of oak and it comes from different places so, as with all wood, be sure to ask what you are getting and where it’s come from – not always information suppliers will have to hand. Asking whether or not it is FSC or PEFC certified is a good start. As an example, I believe this is English oak, but the supplier was a bit vague (which is a bit of a warning sign I think) and I’m still trying to get more solid info from them as they are a supplier we may want to use again.
Here we have cleared the ground for the bed and set the sleepers down on a thick bed of grit sand. All wood tends to rot first at or around ground level, and using a well compacted grit sand or gravel bedding helps to make sure the ground drains really well immediately underneath the wood so it doesn’t sit in water, and also, at least temporarily, it keeps some of the soil-borne life away.
For this bed we have used the sleepers on edge to give maximum height. Sleepers are more unstable this way up rather than sitting flat, so it’s a good idea to use solid stakes, for example fence posts like we’ve used, to secure the sleepers onto horizontally so they can’t tilt or fall over. Using sleepers flat you can often get away with just fixing down through the top of each row, which is fine if you have corners that will also lend stability. Too many rather than too few bolts are a good idea, in my book. We use Timberlok bolts (they call them screws, but I always call them bolts) which come from the USA and are pricey, however they will zip straight through virtually any wood as long as you have a drill with enough torque – and they are stronger than a strong thing on holiday in strong town.
Once this bed was complete we lined the inside with plastic membrane, to keep the soil away from the wood, and gave it a coat of pure raw linseed oil on the outside (not boiled linseed oil which has chemicals in it). Oak can happily be left untreated and will fade to a lovely silvery grey over time. The linseed oil darkens the surface of the wood quite a lot, especially if the surface is fairly rough. Sanding down the wood once you’ve finished can give a really fine, smooth finish, if rustic is not your thing.
So, what do you think?
Coming soon, bespoke log stores!