What is the correct way to cover a greenhouse film? Detailed method explained

With the advent of synthetic polymers - polyvinyl chloride and polyethylene - plastic films have been widely used in agriculture. So, what is the correct method for covering a greenhouse film?

1. Preparation for film covering

1. Personnel preparation

Taking a greenhouse 100 m long from east to west and 9.5 m wide as an example, at least 20 people are needed to take part.

2. Film preparation

The vegetable greenhouse film is divided into two pieces, one roof film and the other a ventilation film. For the former, it is advisable to choose films such as EVA or PO with high light transmittance, strong anti-drip and anti-fog performance, and long service life; the length should preferably be about 98 m and the width about 10.5 m, and a “pull rope” should be threaded through the upper end of the film in advance. For the latter, it is advisable to choose an ordinary greenhouse film, with the same length as the former, a width of about 3 m, and likewise a pull rope should be prepared.

3. Tool preparation

Several pliers, wire tighteners, bamboo poles, iron wire, steel wire, film-pressing ropes, etc.

2. Covering the greenhouse film

To cover the greenhouse film, it is best to choose a sunny, windless afternoon. Covering the roof film can be divided into four major steps:

Step 1: Pull the film onto the greenhouse. For example: from the east side of the greenhouse, 20 people are needed; every 5 m, they lift the film in turn, and along the front of the greenhouse, carry one end of the film to the west side of the greenhouse. Then, another 10 people pull up one side of the film (the side with the pull rope), go up from the bottom of the greenhouse, walk upward along the arch poles, and pull the film onto the roof surface, while the remaining 10 people hold the film in place and help the other 10 people pull the film.

Step 2: Fix the upper end of the film. Method: one person first fixes the steel wire to the pull rope at the east side of the greenhouse, and another person pulls the pull rope at the west side of the greenhouse, so that the steel wire can be threaded through the film; afterward, fix this end of the steel wire to the ground anchor at the west wall of the greenhouse, and fix the other end of the steel wire with a wire tightener. Finally, use iron wire to tie the upper end of the film to the bamboo poles, tying once every other bamboo pole. Be careful that the ends of the iron wire after tying point downward, to avoid puncturing the ventilation film.

Step 3: Fix both ends of the film. First, use the edge of the film there to wrap a bamboo pole about 10 m long, then 10 people take the bamboo pole and pull it downward; after it is pulled tight, use iron wire to fix it to the ground anchors, fixing one spot about every 50 cm. To increase strength, it is recommended that the iron wire be wrapped around the steel wire in an S shape. In the same way, then fix the film end on the east side of the greenhouse.

Step 4: Bury and press the front end of the film. At the front edge of the greenhouse, 5 people are needed to roll up the front end of the film with bamboo poles from the east side of the greenhouse; after pulling it down tight, another 5 people bury and press the film with soil and tread it firm.

3. Installing the film-pressing ropes

Following the method for covering the roof film, after covering the ventilation film, film-pressing ropes need to be installed to strengthen the film. The upper end of each film-pressing rope is tied to a ground anchor at the top of the greenhouse, and the lower end is tied to a ground anchor at the front edge of the greenhouse; one film-pressing rope can be placed every 2 m. The key point is to pull them tight and fix them firmly.

Finally, the editor would like to remind everyone that when building a greenhouse, choose a place that faces the sun, is sheltered from the wind, is high and dry, has good drainage, and has no soil-borne infectious diseases.