So, you’ve chosen a suitable site for your polytunnel and made sure that the ground is cleared of vegetation and obstructions. The big day has finally arrived! It is time to begin constructing your polytunnel. Constructing a polytunnel is not too difficult, but it pays to be prepared and take your time.
Before You Begin Constructing a Polytunnel
Don’t underestimate the task that lies before you – constructing a polytunnel can be done in a day by experienced construction experts, but most people should allow at least a long weekend for the work, perhaps longer. Though this is a relatively straightforward job which can be undertaken by a couple of people with even very basic DIY skills, don’t think you’ll have it all done in an afternoon. It is best to take your time, to make sure your structure is sound and secure and will allow you to enjoy it for many years to come. Take the time before you begin to make sure you are familiar with the instructions, understand what you will be doing and have all the necessary tools (and helpers) on hand.
Check out full installation instructions for all First Tunnel polytunnels at www.polytunnels.co.uk. We can also help you to familiarise yourself with the processes involved with our polytunnel construction videos.
Preparing the Site
The first thing to do once you have checked everything over and read the instructions is to accurately mark out the polytunnel site. Marking out the site will allow you to make sure that you get the structure square. Take your time and make sure you get it right first time.
The next step will depend on whether you are erecting the polytunnel on soft ground, or on an area of hardstanding. It will also depend on whether you are trenching the cover, or whether you have opted for a base rail. If you have opted to trench your polytunnel plastic, you will of course have to dig the trench around the area you have marked out for constructing your polytunnel. In this case, however, once you are happy with the position of all your ground tubes you will simply need to hammer these into the ground. If you are not trenching the plastic, you will need to make sure that the ground tubes are firmly held into the ground, usually with anchor plates.
Erecting the Frame
Once the base is marked out and the ground tubes are securely in the ground or attached to the base surface, the next stage is to assemble and erect the hoops of your polytunnel structure. Take your time and you will find that you can follow the instructions and put the structure together without too much hassle.
First, assemble each of the hoops according to the manufacturer’s instructions, using the supplied fittings. Pay careful attention to which fittings need to be on each hoop, and which way round these should go. Also note which side of the ridge pole each fitting should end up on.
Put the hoops onto the ground tubes, making sure all sections are fully engaged.
Assemble the ridge pole that runs down the centre at the top of the hoops and connect all the hoops together. At this point, the structure will become much more rigid.
Add any diagonal bracing that came with your polytunnel structure, along with any additional bracing you have ordered to add extra rigidity to the structure.
Add any crop bars across the top sections of your hoops.
Covering the Polytunnel
The more helpers you have on hand when constructing a polytunnel, the easier it will be to put the cover on your polytunnel structure. It is also best to wait for a calm, sunny day to make the job easier.
- Pull the cover gently and carefully across the frame, making sure that the excess is distributed as evenly as possible around each side.
- If trenching the cover, making sure to pierce it in the bottom of the trench to prevent waterlogging around the polytunnel, otherwise, affix the cover to the base rail. Try to make sure you keep the cover as smooth and taut as possible over the frame.
- On the door ends, cut your cover for the door opening and pleat the edges to hold it in neatly and tightly around the ends of the structure, as per instructions for the particular polytunnel and doors you have chosen. Make sure the pleats face downwards so they do not collect rainwater.
- Finish off edges and trim as required and generally tidy up.
- Tension the cover by raising the hoops (on a trenched tunnel) or by making adjustments to the base rail, to make sure the plastic is fully stretched and taut.
Originally posted 2011-05-27 12:00:33.
Sean Barker is the MD of First Tunnels, and is enthusiastic about providing quality gardening supplies to gardeners across the UK