This house is a single span film greenhouse with no internal columns, so the whole width of the bay is clear ground for a tomato crop and for the equipment that works it. Both side walls are roll up film, which brings the air intake down to crop height instead of leaving the plants in still air. The frame is hot dip galvanized steel, bolted rather than welded on site, and the cover is a three layer compressed PE film. Spans run from 8 m to 12 m and the length is set anywhere from 10 m to 100 m.
A single span house is the simplest answer to a tomato crop: one clear bay, no columns in the middle, and a film cover that can be replaced without working around a multi span roof. On a farm that runs several houses in a block, that simplicity is what makes the houses easy to build, easy to work and easy to recover one at a time.
Tomato is grown on rows, and rows want to run the length of the bay without breaking around a post. A single span house gives one clear width from wall to wall, so row spacing is set by the crop and the machinery rather than by the structure. It also means each house is a separate environment, which is useful when one block is being turned over or cleaned while another is still cropping.
The trade is in the cover area. One wide bay carries more film across a single roof than the same ground covered by narrower bays, so the cover has to be tensioned properly and checked after wind. Houses of this family are grouped on the tunnel greenhouse range page on this site.
Both side walls are roll up film, and opening them is what turns a closed house into a working one. The intake sits at crop height rather than under the ridge, so the incoming air crosses the plants before it reaches the roof space, and the canopy is not left sitting in its own layer of warm humid air. On a tomato crop that shows up in fruit set and in how much of the afternoon the plants stay active.
The walls are opened in stages through the day and closed again when the sun goes off the house, which is the part that decides how well the house runs through spring and autumn as well as summer. A house in the same family built around hydroponic tomato production is described in the compact single span tunnel house for hydroponic tomatoes.
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 and purlins 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, and the side walls roll on their own tube so the cover can be worked without being taken off. A single span house built for the same crop on a galvanized frame is described in the single span film tunnel house with a hot dip galvanized frame.
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, single span with no internal columns |
| Side ventilation | Roll up film side walls on both sides |
| 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 hoops and purlins go up as a frame, and the film is pulled over and tensioned from the ridge down before the side walls are wound on.
Maintenance is mostly about the film and the side wall gear. The roll up tubes and their fittings 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.
Houses of this type are used for tomato and cucumber production, for leafy vegetables and for other crops worked in rows on open ground or in grow bags. They suit farms that run a block of houses and want each one independent, growers moving up from a low tunnel or a shade structure, 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, including work on high tunnel and season extension systems, is published by the United States Department of Agriculture. 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 house 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 house covers the same ground with fewer walls and less edge, which suits a single large block.
Both side walls roll up along their full length, so the opening runs the whole house rather than at intervals. The walls are worked in stages through the day, which is what keeps the house usable in spring and autumn as well as at the height of summer.
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.
