There are a variety of materials that can be used to cover greenhouse today.
With the current explosion of interest from both commercial farmers and backyard gardeners, the options for materials are constantly expanding. Greenhouse covering material includes: polyethylene greenhouse covering 2-Layer Polyethylene Covering Later Patched w/ UV-Resistant Greenhouse Tape.
Polycarbonate (rigid panels or flexible rolls)
Polyethylene Plastic film
Polyethylene Panels (semi rigid panels or flexible rolls)
Fiberglass (rigid panels or flexible rolls)
Acrylic (rigid panels)
Glass is the Traditional “True Greenhouse” Covering Material
Glass has been the traditional greenhouse covering material.
Chances are, the first glass greenhouse you saw years ago was made from hundreds of glass panels.
Glass requires a very costly and sturdy structural system, but if constructed well, can last for at least 30 years and and clean glass always allows good light transmission.
The main problem with glass is that is a poor insulator unless you use double or triple panes.
Glass is also difficult and expensive to replace if broken.
Polycarbonate Greenhouse Panels and Rolls
Single vs Double vs Triple Layer Wall Polycarbonate Panels. Photo courtesy of Colorado State University Cooperative Ext.
Polycarbonate is a very strong and light-weight material. Panels made for outdoor use have UV treatments that help prevent yellowing and deterioration from sunlight and are guaranteed for about 10 years.
The cost for covering the very small A-Frame greenhouse is much more economical using polycarbonate panels.
Polyethylene Plastic Greenhouse Coverings
polyethylene plastic greenhouse covering
Polyethylene Plastic Sheeting
As we have learned, all plastic coverings are not created equal. Choosing the Right Greenhouse film (Henan Yinfeng agricultural plastic, poly-film and greenhouse plastic).
Utility Grade (4 and 6 mil) polyethylene plastic – will last one season exposed to sunlight.
UV protection – Protects plastic film from Sunlight – guaranteed to last 4 years.
Thermal protection – Reflects IR back into greenhouse – claims to cut heating costs 15- 30% and to maintain higher temperatures at night if you don’t heat.
Anti condensation – condensation attached to film can reduce sunlight, also reduces dripping onto plants
Protection from heat – Opaque to reduce light transmission to 55%.
Polyethylene is the least expensive covering for a greenhouse.
Polyethylene Panel Greenhouse Coverings
Polyethylene can also be made into panels, usually with a twin wall construction with air space for insulation in between – can be used to construct greenhouse as rigid panels or can be semi-flexible and be fitted to shallow arches.
UV protected and some are guaranteed to last 10 years.
Fiberglass Greenhouse Coverings
fiberglass greenhouse covering
Fiberglass panels can be clear or translucent, but still lets about as much light into the greenhouse as glass does, and may allow more light in when the sun is at low angles because very little light is reflected.
Vinyl Greenhouse Coverings
Vinyl covering materials are primarily for used for a clear “showroom” quality look.
Users are advised by the manufacturer to use only on the ends of the greenhouse so customers could have a nice, clear view of facilities. Not intended for use as covering for the top of the greenhouse.
Our Choice for a first time Greenhouse Covering
We Used 6 mil Polyethylene Plastic For 2 Seasons
We used a utility grade (6 mil) polyethylene plastic film. It works well with the PVC Pipe structure and is clamped to the PVC pipe with simple homemade clamps cut from short sections of PVC pipe.
If you use polyethylene plastic that is not UV treated, do not try to use it for a second season.
It may look OK at the end of your first season, but it will disintegrate before you make it through the second season, and it is nearly impossible to pick up all the plastic fragments.
We still plan to use the same polyethylene plastic again this year, because we still have enough left over to cover the greenhouse again.
After two growing seasons, the plastic sheeting held by homemade clamps have worked very well.
When fastened correctly and completely closed, the plastic sheeting has even held up to wind gusts of 70 mph, but on an other occasion, when the greenhouse was partially opened for ventilation (and only partially fastened), the plastic sheeting was blown loose by an approaching storm.