Originally Posted by Bob Hobden

I built my own greenhouse glazed with twin walled polycarbonate roof and
acrylic glazed sides. What I have found is that some plants seem to elongate
as if fighting for light (eg. tomatoes) whilst others don't seem to have any
problems (eg. cacti & orchids).
The main problem is the dampness and humidity of the greenhouse rotting the
wood as the condensation always drips down towards the ground rotting the
wood from the bottom. Also a problem where any sloping roof meets wood
inside the house.