Polytunnel Part 4 - The Doors

Hello and welcome to this 4th part in my allotment diaries mini series in which I document the build process and progress of our first tunnels polytunnel.  With the frame now up, the instruction guide from First Tunnels now moves onto constructing some of the wooden elements of the polytunnel structure.  This isn't a job that has to be done onsite, although if you are fortunate enough to have the flat space needed to do this part of the build on or near your plot, then there is of course no reason why you can't also do this onsite.  For me though, it was nice to be able to do a bit of the build at home, and not have to cart all the component materials and tools up to the plot in the car.

With the frame erected, nearly all of the remaining materials yet to be used are for the wooden elements, including the doors, door frames and base rails.  The next part of the build looks at building the doors.  First Tunnel polytunnels come with several door options ranging from standard doors, wide door, double doors, sliding doors and so the list goes on.  For our tunnel, I stuck with the default option of standard width doors.  I'm not concerned about being able to get a wheel barrow into the tunnel, so a standard width door at each end of the tunnel is absolutely perfect.  Some other companies provide one door and then a dummy door at the other end of the tunnel, but I didn't see the point in a dummy door.  You would still have to build the dummy door and the frame, so for the sake of a couple of hinges and some other bits, you can have a second door.  It aids with ventilation and also gives a good second option if the weather is particularly harsh and blowing directly into the other door.

Anyway, all the timber for the doors is delivered in sets.  So, one set of timber for one door and a frame.  There's no need to pull apart all the sets of timber looking for something specific.  Everything you need is in one place.  The other great thing is that the timber is already pre-cut to the most optimal size.  There are still cuts to be made, but they are minimal.  In fact, in the construction of a standard door, I think I only needed to make two cuts on a single piece of batten.

The longest pieces which run down either side of the door are nominal lengths, so there's no need to cut anything there.  Even the horizontal pieces for the width of the door come pre-cut.  Once all these are fixed together with screws and nail plates, the basic frame shape is complete.  The next step is stretching over the green mesh and the polythene over the frame.  This is where the videos that accompany the instructions really come into their own.  I thought it would be really hard to achieve a flat, smooth finish crease free.  Especially with the polythene section.  But when watching the video back and seeing the technique used in the videos, it's actually surprisingly easy.  The mesh and polythene is initially stretched and held into place by staples.

Once the polythene and mesh is stretched in place, lengths of batten are nailed into place to hide the staples, but also to add strength and clamp the plastic and mesh into place more securely.  Finally, all the excess is trimmed off and you are left with a very pleasing and respectable looking polytunnel door.  It's just a question of rinse and repeat for the second door.

This was a part of the build I had visions of causing the most issues for me.  I was worried about things not being square, making a mistake, putting a hole in the mesh or polythene, cutting the batten to the wrong length etc.  Actually though, it was really straight forward and probably the part of the build I have enjoyed the most so far.

This brings us to the end of part 4.  For the next part, we will look at building and installing the door frames.  Now they are built though, the doors themselves won't be taken up to the polytunnel until the end of the build.  We've made brilliant progress so far, and the build is rewarding and enjoyable.  If you can afford the time to not have strict deadlines and maintain an open mind of accepting that things will just take as long they take and that there is no need to rush anything then the whole project can prove to be a great experience all round.

Thanks for sticking with this mini series and my allotment diaries in general.  Hopefully the next phase will be posted in the coming days and you can continue to follow the project with me.