Greenhouse Cover Films

1. Store the rolls of film in a shady area, on a flat surface, balanced and covered. It is recommended to keep a sample piece of film with manufacturers identification for future reference.

2. Before installing the film, paint all metal and wood surfaces touching the poly with latex paint. Never use oil based paint.

3. Avoid film contact with any PVC plastic or vinyl. Replace any PVC or polycarbonate profiles with aluminum or wood.

4. When installing "Sun Saver" films, there is an inside and outside to the films. When you stand in the greenhouse, you should be able to read the words Sun Saver" correctly. If the words are backwards, the film is upside down and the anti-fog properties will not perform properly. See drawings below for proper unfolding guidelines.

5. The film should be installed during early morning morning hours (cold without wind), and pulled evenly down the length.

6. Re-stretching is done after the film gets warmer.

7. Both surfaces of poly should be as smooth as possible to enable better water "sheeting".

8. Do not stretch film on hot days as it will contract when cool and may weaken.

9. When necessary, the films should be stretched between seasons, and especially after string winds.

Click on photo to enlarge!

10. Installation of the roof and side walls should be done at the same time.

11. Purlins with gutters will help remove condensation from film and reduce dripping.

12. Maintain a 3% gutter slope for adequate water run-off.13. Avoid direct spraying of any chemical on film surface.

13. Avoid direct spraying of any chemical on film surface.

14. Use only repair tape recommended for poly film.

15. In summer it is possible to whitewash the roof to reduce heat intensity. This should be done only with recommended materials for polyethylene films. It is not recommended to whitewash films immediately after laying them. Using adhesive materials makes cleaning the films more difficult.

16. Sulphur and insecticides containing sulphur or halogens cause damage and erosion to polyethylene films. When using a spray gun, do not wet the film (especially when spraying tall or trailed crops).

FOR GREENHOUSES WITH TWO POLY LAYERS (INFLATED ROOF):

17. Static air pressures between the two poly layers should be between 0.2 and 0.4 inches of water on a manometer.

18. Use outside air to inflate poly as it is less humid and less likely to contain chemicals.

19. Install a permanent manometer in each roof. Check manometer often to safeguard against developing tears or to discover a loose lock. Too little air on a windy day can cause excessive flapping and too much air on a hot day can cause stretching and weakening of the film.

20. Be sure of the effectiveness of your film fastening system. Most fastening systems rely on tension created by springs in a channel or opposing aluminum profiles. Fastening system can wear out with age, resulting in film coming loose. Warranty does not cover film loosened or damaged by fastening systems.

21. Installation of GT film below 20 degrees F is not recommended and may void warranty.