Covering film: thickness, layers and light

The standard cover on this model is a clear 6 mil greenhouse film, and the covering material thickness can be supplied at 0.12 mm or 0.15 mm. Both are polyethylene films treated for UV protection, which is what stops the sheet from turning brittle and cloudy after its first seasons in the sun.

The house can be covered with a single layer or a double layer. A single layer is the simpler and lighter option and gives excellent light transmission. A double layer - two sheets with a small air gap between them, kept apart by constant inflation - trades a little light for noticeably better insulation, which is why growers in colder regions usually run double. Whichever you choose, the film is held with aluminum clips seated in a grooved channel in the frame, so a torn section can be re-clipped or replaced without dismantling the house.

Because the covering is flexible, the film also needs tensile strength, not just clarity. The films we fit are selected for tensile strength durability so they stay tight in wind instead of flagging and rubbing against the frame. Custom-cut lengths are available on many film styles, so you can order the exact amount your house needs rather than a fixed roll size.

Frame, sizes and structure data

The covering is only half of the story. The structure under it is a frame of hot dip galvanized steel pipe, which resists rust through years of humidity and irrigation splash. The galvanizing is specified against ISO 9223 and BS EN ISO 14713-1 corrosion categories (C2) through (C5), so the protection level is matched to the site environment rather than quoted as one figure for every region. The roof is an arch profile, and the grooved channel frame does double duty: it stiffens the structure against wind and weather, and it is the same channel that grips the film clips.

Key structural figures for this model:

- Span: 6.4 m, 8 m, 9.6 m or 10 m available
- Total structure height: 4.3 m to 6.5 m
- Roof type: arch
- Example layout: 64 m x 40 m, 2,560 square metres of covered area
- Wind load: 0.35 kN/m2
- Operation: manually or electrically operated vents
- Cover fixing: polyethylene film held with aluminum clips

The design suits varied and complex topographic conditions: the arch sheds wind, the structure adapts to different landscapes, and the covering combination prevents heat loss and cold air intrusion while keeping energy consumption low. For buyers comparing covering materials, the same structure family is also offered as a polycarbonate greenhouse, which trades film replacement for a rigid multi-wall sheet - the right choice depends on your crop cycle and budget rather than on one material being simply better.

Systems you can add

The basic house ships as metal structures, covering system and installation accessories. Depending on the customer request, we add:

- Cooling and heating system
- Irrigation system
- Ventilation system
- Fertilization system
- Shading system
- Benches

Because the film cover is the first thing to age, it is worth planning the add-on systems around it: a shading or thermal screen, for example, protects the film from the inside as well as shading the crop, and gutters and vents should be checked each time the house is re-covered.

Where a film greenhouse fits

This covering type is used for vegetable, fruit, flower and seed nursery production. The example layout above - 2,560 square metres on a 64 m x 40 m footprint - is a middle scale unit: large enough for commercial growing cycles, small enough that a re-cover is a manageable annual or biennial task rather than a major project. Export markets are global, and the structure has been designed for all climate conditions.

If you are weighing film against rigid coverings for a specific crop, tell us the crop, the site and your winter temperatures - the answer usually comes down to how many years you want the same cover to stay on the house.

Frequently Asked Questions

Q1: What thickness of film does this greenhouse use?
A: The covering material thickness is 0.12 mm or 0.15 mm, and the standard cover is a clear 6 mil greenhouse film. Both single and double layer covers are available.

Q2: Should I choose a single layer or double layer cover?
A: A single layer gives maximum light transmission and is the simpler setup. A double layer adds an insulating air gap between two sheets and is the usual choice in colder regions where night heat loss is the main cost driver.

Q3: How is the film fixed to the structure?
A: The polyethylene film is held with aluminum clips seated in a grooved channel in the frame. The same channel reinforces the panels against wind and weather, and a damaged section of film can be re-clipped without touching the structure.

Q4: How often does greenhouse film need replacing?
A: Cover life depends on the film type, the UV load at your site and the local climate, so we size the film to the project rather than quoting one number for every region. The structural frame is a separate matter: it carries a 20-year structural warranty.

Q5: Can heating, irrigation or shading be added later?
A: Yes. Cooling and heating, irrigation, ventilation, fertilization, shading systems and benches can all be added depending on customer request, either at order stage or as retrofits.

Q6: What sizes can the film greenhouse be built in?
A: Spans of 6.4 m, 8 m, 9.6 m and 10 m are available, with total structure height from 4.3 m to 6.5 m. The reference layout is 64 m x 40 m (2,560 square metres) with a wind load rating of 0.35 kN/m2.

Talk to the manufacturer

Bozong Greenhouse has been building greenhouses for above 35 years and exports globally. Our engineer department can guide installation on site if required, and customers are welcome to visit the factory. For a covering specification matched to your crop and climate, call +86 191 5068 3942. Further growing guidance is collected by the FAO and by industry press such as Greenhouse Grower.