So there is no shed here. There’s a long, narrow space under the house that we use to store all the garden tools and various bits, but it’s also used for woodwork and making and it’s very crowded down there.
Our composting solutions are also ad hoc. We’re mulching garden waste and putting it into wire cylinders which we have dotted around the orchard and near the water tank where they’re kind of out of the way but not really.
A greenhouse of sorts would also really help to get seedlings started a bit earlier in spring, and lengthen the growing season.
It would be great if we could combine all three things, so that’s what we’ll do: a garden shed with greenhouse attachment and composting bays!
We have a spot for it figured out already, down on the western fence line at the orchard level. It will extend away to the north (downhill), so we will use the fall of the hill to make a space under the northern half for the composting bays.
This structure is a good chance to do some proper design work before tucking in to the actual job. We cracked out Sketchup and built up the shed piece by piece, making sure that everything we are going to need is included. Later, we can read off the design the components we need to buy, and do a pre-build costing.
After a good solid week designing this is what we came up with: a 4mx2.5m shed that anyone would be proud of.
This view is looking from the north back towards the house and up the hill. We have a concrete slab with rammed earth walls on top creating two big composting bays. That structure will provide six stumps for the north end of the shed and across the middle. On the south end are three more concrete stumps.
On top of that are a layer of bearers, joists and chipboard flooring. A timber framework will go on top of that, creating 2.4m high walls to partition off 3m of the 4m length for shed space and 1m for the greenhouse. We’ll finish the floor using some of the left-over blackbutt floorboards from the lounge room.
Timber rafters and a tin roof cap off the shed portion, while standard-sized 10mm shower screen glass creates the greenhouse, held in place by aluminium channel. Under the eaves we will put shiplap western red cedar for a touch of luxury.
The shed portion is clad in western red cedar weatherboards that we’ll paint black. We have a cute colonial style window in the eastern wall and the greenhouse to provide light inside. We’ll run power and water down the western fence line from the house to provide a spot of civilisation.
Inside will mostly be space to hang tools and house garden bits like the wheelbarrow and mulcher; we’ll see if we can figure out a way to have the mulcher’s outlet feed directly into the composting bay. There’ll be a sink inside for washing (something desperately lacking in the yard at the moment), which we already have, picked up from hard rubbish a good two years ago. It used to be in next-door’s kitchen. We’ll have a bench run across the eastern wall and plenty of space and shelves for storage.
While there are some details to be worked out, all the critical structural ideas are sorted. Some things are easier to figure out once the main structure is in place, and you can get in there and figure out the best way to use the space.
For the moment, we can do the composting bays without too much outlay. We can use our SketchUp model to tell us how much dirt we’re going to need:
That 36000-lotsofzeroes mm-cubed is 3.6 cubic metres. Using the 2.2 compression ratio we learned from doing the little wall, that means nearly 8 cubic metres of raw material.
We’re going to change up the rammed earth mix a little for these walls. There was too much clay in our short driveway wall, and it developed a few cracks as it dried. We found a research paper online that indicated a mixture of 10% clay, 25% silt, 18% sand and 47% gravel stabilised with an additional 5% of cement had much stronger characteristics than other mixes. We can supply the 35% clay and silt from our own site but will need to import the sand and gravel. So we’ll need about 3 cubic metres of our own sifted dirt. Better get cracking!