Just like a home, a greenhouse needs repair if you wish to continue using it. Greenhouses need more frequent repair if they are made using inexpensive materials. For example, a greenhouse made with PVC pipe and builder's plastic will break down faster than one made using UV resistant conduit and greenhouse plastic. Periodic inspections and replacement of broken or worn material will keep your greenhouse in good repair and functional for a long time.
Examine your greenhouse carefully every day as you perform your daily walk through to water plants. Take note of any wear marks, tears or other problems that will need to be fixed.
Feel the plastic to determine how brittle it is. If the greenhouse is made of inexpensive plastic, such as builder's plastic, you may wish to replace the entire skin with a longer-lasting greenhouse plastic. If you just want to repair the tear in the skin, cut a piece of new greenhouse plastic into a patch that is larger than the tear. Apply double-sided greenhouse repair tape to one side of the patch. Peel the backing off of the tape and press the patch over the tear.
Remove the greenhouse plastic skin completely if you want to replace the plastic with more durable polythene greenhouse plastic. Unroll the new plastic over the top of the greenhouse. Then unfold the sides until the plastic completely covers the greenhouse arch. Secure the plastic to the greenhouse by stapling it in place.
Look over any broken or cracked PVC pipe ribs. Slip the damaged PVC pipe off of its anchor and slip a new piece of PVC pipe into place.
Paint the PVC pipe to protect it from UV rays that will make it become brittle and break faster.