The Norhage Tre 300 10x39 wooden greenhouse is the longest polycarbonate greenhouse Norhage build. Thirty-six square metres is a serious growing space. Schools and community gardens tend to ask about this size.
The build does not change with length. Swedish pine frame, solid plywood arches, 3000mm across and 2300mm to the ridge. What changes is how many bays sit between the two ends.
Light arrives diffused through the twin-wall sheets, which is what you want over a run this long. Direct sun through a clear roof would scorch some beds and starve others.
Six millimetre twin-wall is standard. Sixteen millimetre makes the most sense on the twelve metre model. It is the biggest volume to heat, so it gains most from the thickest sheet.
Wood breathes with the weather, so the frame moves a little across a year. Nothing dramatic, but it is not a fit-and-forget structure the way aluminium is.
Please note the polycarbonate is delivered in full standard sheets, not cut to size. Over twelve metres a frame varies slightly once built. The sheets are sized generously and trimmed on site.
- 3000mm (9ft 10") Wide Wooden Greenhouse - Beds down both sides with a path between.
- 12000mm (39ft 4") Long - Thirty-six square metres, our longest Tre 300.
- Impregnated Swedish Pine Frame - Pressure treated before it leaves the factory.
- Solid Plywood Gothic Arches - Curved roof sheds snow instead of holding it.
- 6mm Twin-Wall Polycarbonate - Traps a layer of air to hold the heat in.
- UV Protection - On the outer face of every sheet.
- Ridge Height 2300mm (7ft 7") - Headroom to work standing up.
- Door 850mm x 1920mm (2ft 9" x 6ft 4") - Wheelbarrow width, no stooping.
- Window on the Rear Gable - Opens for airflow and a through-draught with the door.
- 280 kg/m² Snow Load - Engineered for Nordic winters.
- 25 m/s Wind Rating - Holds up on an exposed plot.
- Roof Vents and Automatic Openers - Available as optional extras.
- Free Delivery - Within 5 weeks of order.
Greenhouse width
3000mm (9′ 10″) (9ft 10")
Greenhouse depth
12000mm (39′ 4″) (39ft 4")
Ridge height
2300mm (7′ 6″) (7ft 7")
Door size
850mm (2′ 9″) x 1920mm (6′ 3″) (2ft 9" x 6ft 4")
Growing area
36 square metres
Minimum base size
3000mm (9′ 10″) x 12000mm (39′ 4″)
