The cloche consists of a wooden frame with hoops of plastic water pipe at each end and is covered by clear polythene sheeting. This design is for a cloche measuring 1.2M by 1.08M by 0.5M high (4’x3.5’x1.5′) but you can make them any size you want.
Timber, 50mm x 25mm, 4.6M ( I used scrap timber from an old garden shed!)
Corner plates, 4 off, 3.3M – 15mm Alkathene plastic pipe, the (blue) type used by water supply companies. Dowel for center, 1.2M. Wire for sides, 2 X 1.2M. Plastic sheeting for cover.
Start by cutting the timber to size, try to make sure all the cuts are square as this will help maintain rigidity. Screw the angle brackets on the inside of the joints, remember you will need to drill a hole in the top for the dowel. When you have the frame complete paint with a water based wood preservative.
Drill 4 holes of a size that is a tight(ish) fit for the dowel.Cut the plastic pipe to the correct length, this will depend on the height desired, each of my loops was 1.64 M long which gave a height of 0.5M. Cut 4 pieces of dowel and push up theends of the pipe leaving enough for a flush fit in the frame.
Drill a hole in each section of plastic tube exactly at the top centre for the dowel. Try to make sure you do not drill all the way through the pipe. Fit the end loops in the frame and push the dowel in the centre holes. This version has additional wire supports at the sides which helps to prevent the plastic sheet from sagging. The wire was fixed to the plastic pipe bymaking small holes with a hot nail and then passing the wire right through the pipe and looping it.
Do not pull the wire too tight as this will distort the plastic hoops. You could use 2 additional lengths of dowel at the sides but this would increase the cost.Finally cover with the polythene sheet attaching it to the frames with a staple gun or by using light battens. Stand back and admire your work! The total cost for the first version was around five pounds using scrap timber, commercial cloches are currently retailing for eight times this price!