Two houses can look identical and be ten years apart on the sheet. This one is quoted around the sheet specification rather than the picture: 8 or 12 mm hollow polycarbonate with a UV resistant layer, held in a grooved channel frame on hot dip galvanized steel, in bays of 6.4 to 10 metres and heights to 7.5 metres. The four figures that decide what the sheet is really worth are thickness, wall count, weight and how the UV layer was applied.
A polycarbonate sheet without a UV layer goes yellow and brittle in a handful of seasons, and there is no repair for it beyond replacement. That is why the sheet specification matters more than the frame on a PC house, and why this page is written around it. It belongs to the polycarbonate greenhouse section of this site.
The UV protection on a good hollow sheet is a co-extruded layer on the face that sees the sun, not an additive mixed through the plastic. The layer is what holds the surface against chalking and yellowing; the quoted sheet life of 10 to 15 years is really a statement about that layer.
Two practical consequences. The sheet has a right way up, and the side with the UV layer must face out. And the cut edges must be closed, because an open-ended multiwall panel collects dust and algae in the cells and stops being either clear or insulating.
Panels are 8 mm or 12 mm hollow sheet, set into a grooved channel profile rather than clamped on the surface of the frame. The channel holds the panel edge, keeps the fixing line out of the weather and stops a panel lifting in wind. The frame is hot dip galvanized steel pipe, with aluminium sections where the detailing matters more than the span.
| Type | Multi span PC panel greenhouse |
| Covering | 8 mm or 12 mm polycarbonate hollow sheet |
| UV protection | UV resistant layer on the outer face |
| Panel fixing | Grooved channel profile |
| Frame | Hot dip galvanized steel pipe, aluminium option |
| Span | 6.4 / 8 / 9.6 / 10 m, wider to order |
| Length | 10 m to 100 m or to order |
| Total height | 4 m to 7.5 m |
| Light transmission | 90 to 95 percent |
| Sheet life | 10 to 15 years |
| Impact | About 200 times glass and 8 times acrylic, per the sheet supplier |
Four figures tell you what you are buying: the thickness, the number of walls, the weight per square metre, and whether the UV layer is co-extruded or applied. Thickness alone is a weak guide, because a five-wall sheet at 16 mm behaves differently from a twin-wall at the same figure.
Weight is the honest one. It cannot be faked, it tracks the amount of material in the sheet, and it is the number to compare when two quotations look the same on paper.
Panels go up after the frame is square, with the protective film left on until the panel is fixed and the UV face pointing out. Edges are closed with the profile or tape, and the sheet is not walked on: polycarbonate takes an impact that would break glass, but a point load from a boot is a different test.
Allowance for thermal movement matters on a long run. A panel fixed hard at both ends in cold weather buckles in summer, and the fixing holes are sized for that rather than for convenience.
A second PC range on the same sheet specification is described on the large scale PC greenhouse page, and a twin wall kit on the twin wall PC kit page.
Panels are held in channels and can be replaced individually, which is the practical advantage of a panel house over a monolithic cover: storm damage is a morning's work rather than a season. The sheet life of 10 to 15 years is quoted by the supplier and depends on the UV layer and on how often the surface is washed.
Trade fair and market information for the sector is published by Fruit Logistica, and horticultural business coverage by HortiBiz.
Yes. We customize span width, bay length, gutter height, covering material (film, PC sheet or glass) and ventilation configuration. Share your crop type, local climate and growing area, and our engineers will size the structure to match.
The hot-dip galvanized steel frame carries a 10-year structural warranty covering structural safety, plus a 5-year warranty against corrosion perforation. It is designed for a 15-20 year service life. Film covers carry a 3-5 year UV warranty depending on grade.
Film suits low-cost tunnels on 3-5 year replacement cycles. Glass delivers the highest light transmission and the longest lifespan, at the highest cost. PC sheet insulates better than film and suits cold or high-humidity climates. The right choice depends on climate, crop and budget.
A standard multi-span greenhouse is typically erected in 2-4 weeks, depending on the span, the number of bays and site access. Foundation work and glazing are the two stages that set the pace, and both are scheduled before the frame arrives.
The side with the UV resistant layer, which is co-extruded on the face that sees the sun. Panels have a right way up, and the protective film stays on until the panel is fixed so the layer is not scuffed during installation.
Yes. Panels are set in channels and come out one at a time, which is the practical advantage of a panel house: storm damage is a morning of work rather than a season.
