How to make a Triple-bay compost bin

Use one bin for fresh scraps, one for decomposing material and one for usable compost, says Rose Hughes.

Three bay compost bin.

You will need:

• 26m – 100 x 50mm dressed untreated timber (Douglas fir preferred). • 12m – x 50 x 50mm posts. • 18m – 150x 25mm untreated timber. • Optional: 11m – 150 x 25mm (for end caps). • 10g x 100mm screws. • 8g x 65mm screws. • Chisel and wood rasp or sandpaper. • Screwdriver / drill and bits. • Clamps. • Drop saw / skillsaw. • Staple gun and staples. • 8m chicken wire. • Resene Waterbourne Woodsman Stain and a paintbrush.

Cutting List:

100 x 50mm – 8 x 940mm & 12 x 770mm, 3 x 2900
50 x 50mm – 6 x 1000mm with pointed ends & 6 x 940mm (flat ends)
150 x 25mm – 8 x 900mm (optional 12 x 910mm)

Cost: $470 (excluding paint)

The slats at the front can be built up or removed one by one as material builds up, or as fresh compost is used.

Instructions

Step one
Clamp two 940mm pieces together. Cut a 20mm offcut from the 100 x 50mm timber. Use this as a template for the cut-outs. Mark a cut-out at the top, bottom and centre. Set the skillsaw blade to 20mm cutting depth. Slice cut the marked areas. Clean and rasp flat.

Step two
Drill two centred guide holes per cut-out and using the 100mm screws join the dividers together with the shorter pieces forming the top, bottom and middle.

Step three
Using the drop saw, cut points on the six long 50mm x 50mm posts. Using the 65mm screws attach these to the front edges of the dividers, one each side on the two internal ones and one only on the inside edge of the external ones. Cut a short piece of the 150mm slat to use as a guide. Attach the shorter posts, ensuring the slat will run freely between.

Step four
Because this timber is untreated and to help it last a little longer, I coated the front slats with Resene Waterbourne Woodsman stain. I used Nutmeg, Timberland and Bark.

Step five
Move the pieces into their final position. Screw the back struts in place. Cut chicken wire to length. Release the screws on the internal posts and tuck the wire underneath. Attach around the edges with staples.

Step six
Add a slat to each section and push the post points into the ground. Add the remaining slats. Attach the end caps (optional).

Photos: Rose Hughes

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Resene Paints Ltd – www.resene.co.nz