One of the hardest things about producing your own food isn’t growing it, it is storing it afterwards. It really wants to break down as fast as possible, and all manner of creatures want to eat it first. Until now we’ve stored food all over the place – hanging up in the living room; in cupboards. In short, not ideal. Another issue that we had was that our 4000 litre rainwater tanks and pump were not terribly pretty and very exposed to cold temperatures. The pump especially has been badly damaged by freezing twice now. The problem, as they say in permaculture, is the solution, and in this case takes the form of a strawbale barn, which incorporates the water tanks as its back wall.
The bulk of water on the south side of the building will act as thermal mass, evening out the temperature within the barn, and the barn will in turn prevent the tanks and pump from freezing.
Our budget for this build was virtually nothing, and so we’ve used recycled or low cost materials throughout. The foundation is made from two courses of rammed earth tyres, topped with gravel.
On top of this sits the strawbale wall, which is pinned into the bales with rebar and willow stakes. Window openings are formed from old scaffold boards. We experimented by creating a wall plate from two lengths of 2″ blue water pipe, which is pinned and lashed to the top of the bale wall.
The self supporting reciprocal roof is made from birch poles, which are fixed together where they meet with fencing wire, and to the wallplate with metal strap. On top of these is a deck of sawmill skins. which is in turn covered with a layer of white weed suppressant fabric (a gift from a neighbour).
Then a layer of straw, followed by a couple of layers of plastic silage sheet, which are in turn protected by another layer of weed suppressant and old carpet. Soil and turf is then sitting on top of all that.
Although the walls are supposed to be load bearing, I couldn’t resist putting in a sturdy pole beneath every other rafter, to help support the weight, and an internal platform over the water tank tops means I also added a supporting pole near the centre of the roof, which will also carry the platform.