At roughly what height above ground would you install the horizontal metal channels for holding the plastic sheet to the greenhouse frame?
I’m planning to make a small (10-foot x 17-foot x 9-foot high) greenhouse by covering the frame from a Coverpro ‘portable garage’ structure with 6-mil UV-treated plastic sheet. To hold the sheet in place and to tension it I’m looking at using metal channels with wiggle wire.
If I’m understanding correctly, some folks will leave part of the bottom of the greenhouse open to allow ventilation air to enter, but at other times will want the plastic sheet to extend all the way to the ground.
What is a good height above ground to position the channels in order to both provide good tension and support for the sheet, but also to permit opening up the bottom area for ventilation?