Greenhouse Polycarbonate

  • Greenhouse polycarbonate is crystal clear like glass. This is incorrect. Twinwall or triplewall polycarbonate is used for greenhouses. The easiest way to describe it is to envision looking down the end of a cardboard box. There is a sheet on the outside, a sheet on the inside and a rib that runs directly between these two sheets. Although the exterior sheets both have glass like clarity, the center rib will distort your view. You will see colors, but not forms clearly.
  • Greenhouse polycarbonate is difficult to cut. No, it isn’t. The sheets can be cut with a circular saw, a table saw, even a jig saw with a fine tooth blade. Simply cut it as you would a sheet of plywood. If you would like, you can use compressed air to remove any dust from the channels.
  • I can store my greenhouse polycarbonate in direct sunlight for an extended period of time. Oh, please do not do this. There is a protective film on the sheets. This is for protection during transport and also to direct you which side of the sheet needs to go out to the sun (UV protected). If you leave the sheets uncovered in the sun for an extended time, the protective film will melt into the sheets and become impossible to remove.
  • I can bend my greenhouse polycarbonate in as tight of a circle as I want. Incorrect again. There is a minimum bending radius specified by each manufacturer for each thickness of sheet. Please be sure to request this information if your design calls for bending of sheets.
  • The sheets are going to be heavy and difficult to handle. Nope. A 4′ x 12′ sheet of 8mm clear twinwall polycarbonate will weigh approximately 20 pounds.
  • I need to silicone all of my joints. Not necessary. The profiles that come with the sheets (H, U, R and F) all fit tightly and do not require silicone when installed according to manufacturers specifications.
  • I don’t need to order my sheets for my entire roof length. I will just join them together with an H profile running horizontally. This is the worst offense of all. Your roof will leak at this joint, and become a moldy mess. Please be sure to order your sheets for the entire length you will need.
  • I can run my sheets with the ribs running vertically or horizontally, whichever I prefer. NO! The sheets must be run with the ribs vertically so that any condensation which forms in the channels can drain.
  • I can lay greenhouse polycarbonate flat. Nope! You must have at least a 1 on 12 roof pitch, or 5 degree slope. Many have tried going flatter. Many have been unhappy when their roof leaks. There is no way to fix this and no way around this rule.
  • Greenhouse polycarbonate will only last a couple of years. Not true. Most manufacturers supply a ten year warranty on the material. Some even have 15 year warranties now. Polycarbonate typically exceeds the warranty period while still performing and looking good.