The best coldframes and greenhouses are glazed with ribbed, triple wall polycarbonate.
This high-tech plastic (also used for airplane windshields and football helmets) is able to withstand extreme temperatures and high impacts.
Triple walled polycarbonate also has 40% more insulation value than single pane glass, with nearly equal translucence.
The ribbing scatters light evenly, eliminating hot spots and promoting straight, uniform growth.
Triple wall glazing sheets for building your own greenhouse.
Transmits 75% of visible light and comes in a 4' x 8' size.
U-factor is .528 R-factor is 1.89
It contains a UV barrier to increase the longevity of the sheets.
This material is 1/16 the weight of a single pane of glass.
Actual width is 47.25" to allow for expansion. Thickness is 5/16"
Rib spacing of the plastic that comprises the triple wall is 0.3125"
Limited 10 year warranty.
Note: Before removing the outer film covering on panels, check to see which side must be placed on the outside.