A finished greenhouse requires a cover of some kind. One of the most inexpensive covers that is easy to attach to a wooden greenhouse frame is high-quality plastic sheeting. High-quality plastic can last for several years without becoming ripped, torn or disfigured; however, it does need to be attached with proper care in order to make it last. If the plastic does become ripped or disfigured, it is easy to replace using the same techniques. Work with a partner or group to attach plastic to your wooden greenhouse frame.
Measure each section of your greenhouse before you cut sheeting for it. Attaching sheeting in several smaller pieces can help it last longer.
Measure out enough plastic sheeting to cover one section of your greenhouse; for example, a square of plastic sheeting that is large enough to cover part of one wall. Add 6 inches to all sides of the sheeting.
Pull the sheeting taut across the surface you are covering so that there are no puddles or loose sections of the plastic.
Fold the edges of the plastic around a wooden support on all sides. Do not attach plastic sheeting to the face of the wood.
Fold the excess sheeting back to form a double layer of plastic to protect the sheeting and the wood.
Use roofing nails to attach the plastic to the wood. Nails should be placed close together for maximum strength; put one nail every 12 to 13 inches along the plastic.
Repeat this process for every section of the greenhouse.