Ingredients
9 of 3.6m yellow 47x22mm roofing battens
2 of 3.6m 75x50mm treated softwood timber
Impermeable membrane: 1 piece 1.8m by 0.6m, 2 pieces each 0.65m by 0.7m; the cheap version is to cut up the bags from the compost with which you fill the planter.
8mm staples
Garden paint or wood preserver
180 or so 4x40mm screws
48 4.5x65mm screws
4 castors (capable of bearing 55kg each)
Castors are available on Amazon but a fairly cheap way of getting them is to buy a 200kg “dolly” from B&Q, remove the castors and use them on your plant theatre
. The ones I bought on Amazon came with their own screws which were a good size. The ones I got from B&Q, I had to buy screws and then washers to stop the screw heads going through the screw holes in the plates for the castors. Also, if you buy the castors as castors, it is possible to get two with brakes so you can anchor the planter in place.
Tools
Drill (2.5mm bit), Screwdriver, Mitre saw, Staple gun, Paint brush