Greenhouse Cladding Materials
This domain tests material selection for light transmission, durability, insulation and cost. You must compare polyethylene film, polycarbonate sheets, glass and shade nets without treating any one as universally best.
Material comparisons
- UV-stabilised polyethylene film: 200 micron is common; light transmission about 85–90%; service life 3–5 years. Add anti-drip and anti-fog grades in humid houses.
- Twin-wall polycarbonate: 8–10 mm sheets; light transmission about 75–80%; life 10–15 years; better insulation but higher cost and dust accumulation.
- Glass: high light transmission, long life, heavy frame requirement, high cost and breakage risk.
- Shade net: 35–50% shading for summer; black net also reduces light in winter, so coloured or aluminised nets may be chosen where light is limiting.
Worked example
A grower in Nashik wants capsicum under a 1,000 m² house and can fund either 200-micron UV film replaced every 3 years or 8 mm twin-wall polycarbonate. Reasoning: capsicum needs good light; polycarbonate loses some light but gives longer life and better heat retention at night. If summer is the main constraint, diffused film plus 35% shade is cheaper. Decision: film with anti-drip and diffused properties for the first cycle, with a replacement reserve in the budget.
Traps that cost marks
- Using non-UV film and finding it brittle within one season.
- Choosing black shade net for a low-light winter crop.
- Ignoring dust and condensation losses when comparing light transmission.
- Forgetting that anti-drip film reduces leaf wetness and disease.