This house is a single span film greenhouse on a hot dip galvanized steel frame, built for tomato production at commercial scale. There are no columns in the bay, so rows run the full length of the house and the crop is worked and picked without breaking around a post. The frame is bolted rather than welded on site, which keeps the coating intact and lets a member be replaced on its own. Spans run from 8 m to 12 m and the length is set anywhere from 10 m to 100 m, or built to client demand.
A single span house is the simplest way to give a tomato crop what it wants: one clear bay, no posts in the rows, and a roof that can be recovered without working around a multi span structure. On a farm running a block of houses that simplicity is what makes them easy to build and easy to work one at a time.
Tomato is grown on rows, and rows want to run the full length of the bay without breaking around a column. A single span gives one clear width from wall to wall, so row spacing follows the crop and the picking trolley rather than the structure. The same clear bay is what lets the trellis and the irrigation main be laid out to the crop instead of fitted around it.
The second reason is independence. Each house is a separate environment, so one block can be cleaned, turned over or recovered while the house next to it is still cropping. Houses of this family are grouped on the tunnel greenhouse range page on this site.
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. Hoops, purlins and the base rail are bolted rather than welded on site, which leaves the coating intact and lets a bent hoop be unbolted and replaced instead of cut out.
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. Film is held on the hoops and the base rail with clips, so a panel can be released and retensioned without a full recover. A house with the same cover and a wider bay is described in the farm tunnel house for tomato and vegetable growing.
Once the canopy closes over the rows the air inside it stops moving on its own, and that layer is where the humid air and the warm air collect. Openings at crop height bring air across the leaves rather than over the top of them, which is what keeps a tomato crop working through the afternoon and keeps the fruit dry into the evening.
The working arrangements matter as much as the growing ones. A single span house of this width takes a picking trolley down a central aisle with a row either side of it, and the height at the gutter is set so the crop can be trained upward without the operator working above head height all day. A house on the same principle with a multi span roof is described in the commercial multi span tunnel house for tomato growing.
The table below is the standard build. Span, length, height, cover and openings 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, single span with no internal columns |
| Ventilation | Side wall openings at crop height and gable openings |
| Cooling | Fan and pad cooling system optional |
| Crops | Tomato, cucumber, leafy vegetables, fruit and flowers |
| Customisation | Span, length, height, cover and openings set to the site |
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 hoops and purlins go up bay by bay, and the film is pulled over and tensioned from the ridge down before the side openings are fitted.
Maintenance is mostly about the film and the openings. The side wall gear and the gable openings are the working parts, so they are checked and greased before the season turns. 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. Bolts and the base rail are walked once a season, with the shoulder of each hoop the place to look after a windy spell.
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 tomato growers running a block through the season, farms extending a range one house at a time, and operations that expect to add irrigation, cooling or a control system to the same frame later.
Research and extension material on protected crop production and on high tunnel systems is published by the University of Florida IFAS. Production and market reporting for fresh produce growers is published by FreshPlaza. The specification that matters is the one that still suits the crop ten years from now.
Clear width and independence. A single span has no columns in the crop, so rows run the full length of the bay, and each house can be cleaned or turned over on its own. A multi span covers the same ground with fewer walls and less edge.
It is set by the row layout and the trolley. The bay has to take the rows plus a working aisle, and the span and post spacing are then chosen together to give the clear height needed at the gutter for the trellis and the crop.
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 and snow figures. We reply with a layout drawing and a full quotation.
