Greenhouse plastic is mainly responsible for maintaining a hothouse effect within a greenhouse. Greenhouse plastic creates a warm and suitable growing environment that allows various types of plants to cultivate beautifully. It creates an enclosure that protects plants from the harmful ultraviolet rays of the sun while taking advantage of its natural warmth and light. The filtered environment produced by greenhouse plastic makes it possible for garden enthusiasts to grow luscious plants like vegetables and flowers in the cold dead of winter.
Greenhouse plastic is explicitly designed to resist wear and tear unlike conventional construction plastic that cannot filter ultraviolet rays from the sun. Greenhouse plastic is durable due to its knitted design that allows it to be cut and sized to meet the required length for a structure without fraying, ripping or tearing. The material can easily be framed around any greenhouse opening like a vent, door or windows.
Greenhouse plastic is the preferred covering of most garden enthusiasts compared to other types of greenhouse covering. At the same time costs are greatly reduced when greenhouse plastic is used since it lightweight and does not require heavy-duty structural framing. The diffusion of light into a structure constructed of greenhouse plastic is as good as that of a glass greenhouse.
Types of Greenhouse Plastic
Greenhouse plastic films are generally made of three types of plastics namely, PVC or polyvinyl chloride, PE or polyethylene and copolymers. Although, there are other types of plastic used these three are most widely used among all.
Polyethylene greenhouse plastic is available in two types, the utility grade and the commercial grade greenhouse plastic. Utility grade polyethylene greenhouse plastic is sold at local hardware stores and generally stays in good condition for practically a year. Commercial grade polyethylene greenhouse plastic last longer that utility grade PE up to eighteen months and is treated with ultraviolet inhibitors that filter out ultraviolet rays.
Copolymers are more durable and last up to three years. Innovative additives introduced into greenhouse plastic enable it to mimic the same effects of a glass greenhouse at considerably reduced costs. Polyvinyl chloride is more expensive compared to polyethylene however this type of greenhouse plastic can last up to five years. However PVC greenhouse plastic requires regular washing to prevent dust buildup from the air. It is also sold in smaller sheets of four feet by six feet wide.
How to Attach Greenhouse Plastic to Frame
Once the frame has been built it is time to put on the greenhouse plastic film to enclose the entire structure. The plastic film can either be made of polyethylene, copolymers or polyvinyl chloride depending the preference of the owner. But as much as possible choose a greenhouse plastic that is resistant to ultraviolet rays in order to make the most of the structure. Before laying the greenhouse plastic covering on the frame it is important to mask the joints of the frames with several rounds of tape or a rubber material to prevent it from puncturing the covering.
The greenhouse plastic film can be secured in place using a staple gun. A more rigid construction using 1" by 2" wood strips and wood screws can also be used to secure the greenhouse plastic film in place. The wood strips are attached to the frame so that the greenhouse plastic film does not come in direct contact with the frame.
A popular technique used by nurseries is a double-walled construction for better insulation within the structure that adds up to considerable energy savings. Two sheets of plastic are layered and framed leaving a small amount of space in between about five to eight inches wide. Air is introduced into the framed plastics that produce a dead air zone, which can efficiently insulate the entire greenhouse. Various tapes like poly patching tape and batten tape can be used to secure greenhouse plastic into place.
Poly patching tape is constructed from UV protected acrylic along with the adhesive to protect the greenhouse plastic from weakening on contact with it. This type of tape can be used to patch holes and rips that may happen to the plastic film. Its excellent holding strength and wide tape make an ideal for securing the plastic film to the frame of the greenhouse. On the other hand batten tape can be fastened the plastic film using staples or tacks to the greenhouse structure. It is also made of heavy gauge vinyl that is also UV protected.