18ft × 78ft Heavy Duty Commercial Polytunnel Kit: Professional Greenhouse

Take your growing to the next level with our 18ft × 78ft Heavy Duty Commercial Polytunnel Kit — a professional-grade structure designed for serious growers, allotments, and smallholdings. Built from premium materials, it offers outstanding durability, generous working height, and a stable growing environment all year round.

What's Included

• Frame: 35 mm diameter Z35 galvanised steel hoops, 1.2 mm wall thickness
• Hoop Spacing: 5 ft (1.52 m) centres with ridge and crop bars for extra strength
• Bracing: Corner struts and wind braces included as standard
• Cover: 720 g/m² UV-stabilised diffused polythene with 5-year guarantee
• Fixings: Full set of galvanised clamps, brackets and tensioning components
• Base: Heavy-duty ground tubes for concreting or hammer-in installation
• Protection: Anti-hotspot tape, repair tape, and printed instructions

Optional Upgrades

• Hinged timber door kits (single or double width)
• Roll-up side ventilation kit
• Additional internal crop bars or staging
• Replacement covers & spare fittings

Dimensions & Technical Specs

• Width: 18 ft (5.49 m)
• Length: 78 ft (23.77 m)
• Ridge Height: Approx. 8 ft (2.44 m)
• Side Clearance: Approx. 3 ft at 2 ft from side
• Steel Tube: 35 mm dia. Z35 galvanised
• Cover: Diffused light, anti-drip, 720 g/m², 5-year UV guarantee
• Estimated Weight: 160 kg
• Wind Rating: Suitable for exposed sites when anchored correctly

Why Choose This 18x78ft Polytunnel?

• Commercial-grade strength and stability
• Generous internal height for comfortable working
• Diffused cover promotes even light and reduces scorch
• Built to withstand the worst of the UK's wind and weather
• 5-year cover guarantee and long lifespan steel frame
• Full UK customer support and spare parts available

How to Install Your Direct Plants Polytunnel

• Supplied as a self-build kit
• Requires 2–3 people for assembly
• Typical build time: 1–2 days
• Tools needed: spanners, drill/driver, spirit level, hammer
• Must be installed on level ground and securely anchored
• Clear step-by-step printed instructions included

Delivery, Warranty & Support

• Fast UK mainland delivery (typically 5–10 working days)
• Delivery surcharge applies to Scottish Highlands, Islands & NI
• 5-year cover warranty and 10+ year frame lifespan expected
• Full after-sales support and replacement parts service

Buy Your Direct Plants Polytunnel Now

Add this professional-grade 18x78ft polytunnel kit to your basket today — or contact our team for expert advice on sizing, siting, or installation.