Many greenhouse growers are switching from glass glazing to polycarbonate or PVC. Although glass allows 90 percent of sunlight into the structure, it is heavy and breakable. However, there are different types of glass glazing like Toughened which is a safety glass.
When we bought a house in Klaipeda, Lithuania, the greenhouse came with it in a backyard. The structure consists of the wooden frame and polycarbonate cover. Unfortunately, a few weeks ago we had really strong winds up to 32 km/h. As a result, greenhouse roof plastic cover broke and now we need to attach plastic to wood frame.
So, in this post I will tell you how my dad and brother attached plastic sheeting to wood greenhouse frame. For this project you will need certain tools and materials. Most of the tools you can find in the garage and most likely you will need to order plastic covering.
Tools:
Materials:
- Polyester Rigid Plastic
- Screws 30 mm
- Bonded washers
Step-By-Step Guide On How To Attach Plastic to Wood Frame Greenhouse
Step 1 – Measure Plastic Cover
Use measuring tape to find out the height and length of greenhouse roof. For example, we have a 6 ft by 12 ft even span greenhouse structure. So the side of our greenhouse roof is 4.1 ft (1.25m) wide and 12 ft (3.65m) long. Write down the measurements as you will need them to size the plastic.
Most of the time polyester sheeting comes in the rolls. The one that we ordered was 38 meters and we asked them to cut it to 7 meters. Once the roll is delivered, unfold it and lay on the ground. We chose plastic of 0.8 mm thickness.
Tip: When measuring polyester, allow 0.125 inches for thermal expansion.
Step 2 – Cut the plastic
To cut plastic use a saw with a fine tooth blade. When cutting the plastic leave room for error, for example, in taking dimension of the actual wood frame. You can trim off the excess plastic later. Remember to wear gloves and safety goggles when cutting plastic with hacksaw.
Step 3 – Install plastic to wooden frame
Take 1″ self drilling screws with neoprene bonded washers to fasten plastic sheet to greenhouse roof. Hold the top left corner of the first plastic sheet to the top corner of the first side of the roof and screw it in place with a drill. Don’t fasten screws within 0.5 inches of the edge of a polyester sheet.
Use 1″ self drilling screws with washers to install plastic to the length of the horizontal wood greenhouse frame every 6 inches (15 cm). Fasten the screws in the same way along the width of the wood frame of greenhouse roof. When fastening screws, don’t tighten below the surface of the panel.
It is important to use neoprene bonded washers with screws as it is going to prevent water from leaching into the greenhouse from the roof. Moreover, you can use solid foil tape at the tops of the sheets to seal out water and insects, and foil vented tape at the bottom of the sheets to seal out any insects and allow condensation to drain out of sheets.
Although in this project we used polyester to cover greenhouse, you can use a different greenhouse glazing material. Options vary from polycarbonate, plastic film (PVC or PE) or Solexx. Many gardeners are switching to Solexx because it is a twin-wall polycarbonate covering material that is perfect in heat retention. This means that you can save on the heating inside the greenhouse.
However, if you are interested in the temporary option for just one season, you can consider installing plastic film. The utility grade Polyethylene film is a great option and with the appropriate care it can last for one to two years. Also, it is easy to install plastic film to wood greenhouse frame.
How to attach plastic film to greenhouse?
Buy a 6 mil UV resistant clear plastic film and cut to size to fit the specific dimensions of your greenhouse structure. Prepare the wooden frame – sand the outer portions of the frame to smooth the surface. Use a heavy duty staple gun to attach plastic film to the length of the horizontal wood greenhouse framework every 6 inches with 3/8 inch (10 mm) staples, stretching it taut along the way.
Keep in mind that plastic film might not be able to withstand strong winds, so you would need to keep a greenhouse from blowing away. It means securing greenhouse to the ground with anchor stakes and possibly screwing a greenhouse frame to the fence. That is why many growers prefer polycarbonate panels to polyethylene film.
How to secure polycarbonate panels in a greenhouse?
Polycarbonate is a twin or double wall made of Polyethylene plastic. It is lightweight and tough with the 80 per cent light transmission. Due to its double glazing effect it is perfect at heat retention. For greenhouse sides choose 3 or 4 mm thick polycarbonate sheets and 10 mm thick polycarbonate panels for greenhouse roof.
To secure polycarbonate panels in a greenhouse use 1″ self drilling screws with 0.5″ washers for corrugated polycarbonate and 1″ washers for triple wall polycarbonate. As you can see from the picture above, screw on the left is 3/4″ and it didn’t withstand strong winds. This time we used 1″ screws every 6 inches to secure plastic panels in a greenhouse.
