This house is a multi span film greenhouse built for vegetable production at farm scale, on a hot dip galvanized steel frame with a reinforced three layer PE film cover. The frame is bolted rather than welded on site, so sections can be replaced without cutting out a member, and the film is held on the hoops and the base rail with clips. Spans run from 8 m to 12 m and the length is set anywhere from 10 m to 100 m. It is made for growers who run a crop through the whole year and need a cover that stands up to the season rather than one that has to be nursed.
On a working vegetable farm the greenhouse has to keep running through the season that is hardest on it. Wind, snow and a film cover that is worked every week together decide how many days the house is actually producing. A reinforced frame and a multi layer cover cost a little more at the start and are the two parts that decide whether the house is still doing its job in year five.
A film house fails in one of two ways. Either the cover tears and the house is open to the weather, or the frame bends and a bay has to be rebuilt. Reinforcing the frame addresses the second and makes the first less likely, because a stiffer structure moves less in wind and puts less fretting load on the film where it meets the hoops and the base rail.
It also changes how the house is worked. A frame that holds its line keeps the film at an even tension across the bay, so the cover does not slacken into a pocket that holds water or snow. Houses of this family are grouped on the film greenhouse range page on this site.
The cover is a three layer compressed PE film. The layers carry their additives separately, so the anti condensation face keeps working for longer than a single layer sheet does, and the outer layer carries the UV stabiliser. That matters on a farm house, where the cover is the part replaced on a cycle and every extra season of service is one less recovery between crops.
Film is fixed on the hoops and along the base rail with clips and profile, which means a panel can be released and retensioned without the whole cover coming off. On a working site that is the difference between a repair that takes an afternoon and one that takes the house out of production for a week. The same cover is used on the commercial plastic film greenhouse for agricultural and farm planting.
The frame is hot dip galvanized steel, galvanized after the sections are formed, so the zinc reaches the bore of the tubes, the cut ends and the inside of every drilled hole. Columns and trusses are bolted rather than welded on site, which leaves the coating intact and lets a damaged member be unbolted and replaced instead of cut out. The base rail carries the film and ties the hoops together, so the load from the cover goes down through the posts rather than into the film itself.
Spans run from 8 m to 12 m, and the bay width together with the post spacing is what sets how much clear working space the house has. A narrower bay carries a shorter span of film and moves less, which is why wide bays and long spans ask more of the frame than a block of small ones.
The table below is the standard build. Span, length, height and cover are set to the site and to the crop.
| Greenhouse span | 8 m / 9 m / 10 m / 11 m / 12 m |
| Greenhouse length | 10 m to 100 m, or built to client demand |
| Greenhouse height | 3 m to 8 m, or custom |
| Structure material | Hot dip galvanized steel pipe, bolted assembly |
| Cover material | Three layer compressed PE film |
| Roof type | Arch roof, multi span |
| Film fixing | Clips and profile on the hoops and base rail |
| Cooling | Fan and pad cooling system optional |
| Crops | Tomato, cucumber, leafy vegetables, fruit and flowers |
| Customisation | Span, length, height and cover set to the site and the crop |
The kit arrives formed and drilled with the fittings, so the work on site is bolting and tensioning rather than fabrication and no welding is done at any point. Ground posts or a base rail are set to the drawing first, the arches and trusses go up bay by bay, and the film is pulled over last and tensioned from the ridge down.
Maintenance falls into the frame and the cover. The bolts, the base rail and the film fixings are checked before the windy season, because a slack clip is where a tear starts. Film tension is checked after the first season and the cover renewed on a planned cycle, while the galvanized frame runs for far longer than the film does.
Houses of this type are used for tomato and cucumber production, for leafy vegetables and for fruiting crops grown in soil or in bags on the floor of the bay. They suit commercial vegetable farms that run the house all year, growers who are replacing a lighter film house that did not hold up, and operations that expect to add cooling, irrigation or a control system to the same frame later. A lighter film house for mixed farm planting is described in the agricultural plastic film greenhouse.
Research and extension material on protected crop production, including work on the growing environment under cover, is published by AIPH, the international association of horticultural producers. Production and market reporting for commercial growers is published by Krishijagran. The specification that matters is the one that still suits the crop ten years from now.
Stiffness. A stiffer structure moves less in wind, which keeps the film at an even tension and takes the fretting load off the cover where it meets the hoops and the base rail. It also means a bay is less likely to have to be rebuilt after a storm.
On a house that runs all year, yes. The layers carry the UV stabiliser and the anti condensation additive separately, so the anti drip face keeps working for longer than it does in a single layer sheet. It also means the cover is renewed on a longer cycle, which suits a working farm.
The galvanized steel frame is rated for 15 to 20 years under normal growing conditions. The film cover runs on a shorter cycle than the frame, typically 3 to 5 years depending on UV exposure at the site.
We provide a 10 year structural warranty and a 5 year anti-corrosion warranty on the galvanized frame. Details are set out in the contract for each project.
Send your site dimensions, the crops you plan to grow and your local wind, snow and rain figures. We reply with a layout drawing and a full quotation.
