Did not take long to get the answer. Marnie Turkel called me back and relates that the has used Aluminet right on top of Lexan for years without any problem. She is not sure you can do that with black shade cloth as it traps heat but the heat repelling Aluminet lends itself to this. Great, makes for simpler construction and more usable space in the greenhouse.

Nick

I am glad you posted the answer to your own question, Nick. I am right now perusing Lexan sellers for the lean-to greenhouse I am building this summer. I also wondered about the whole shading / spacing situation. Being in Michigan I am thinking I may shade on the inside for the spring/winter/fall and on the outside for the summer.

I'm going to have to purchase a bunch of Lexan. Pretty expensive at HD. Let me know if you find a better source. I havn't started looking yet.

Nick

Our Lexan needs probably differ quite a bit. At a minimum I am looking at 16mm triple wall. I might go with 16 mm 5-wall. My HD doesn't even carry it. The three places I found so far are advance greenhouses, sundance, and multiwallsystems. all .com I have started excavating my site by hand and hope to incorporate shcs. We'll see.

Lisa, maybe you've already looked into this, but you lose a lot of light when stepping up to 5-wall polycarbonate. I considered thicker polycarbonate here in zone 4, but went with 8mm triple-wall on the recommendation of a local commercial greenhouse owner. I'm glad I did, but maybe you have different priorities.

I also use aluminet tied directly onto the outside of my polycarbonate. It definitely reduced the heat load when I put it on this spring.