DIY tunnel

Hey there guys I have seen a few videos on you tube of home made polly tunnels and I am planning on doing one on are new allotment using scaffold tubes and water pipe for the arches has any one here made there own or have any pointers we are pretty screwed together when it come to building things as we both in the construction trade just not something you build every day

 

Here's one that I've always liked the look of:
http://www.overthegardengate.net/UserPages/pp_view.asp?FName=polytunnel&Page=1

Worth keeping an eye out on eBay / FreeCycle for a glass house (unless this is for allotment and glass is banned there - it usually is because of the risk that broken glass gets left in the soil for future tenants. Could use Polycarb instead of glass, but it has a habit of blowing out - folk work around that by silicon'ing it in, but that makes dismantling it pretty tough!

I've picked up a couple over the years - from memory £200 for the 12'x10' and £400 for the 30'x10' one.

 

That is the same idea I have been looking at I already have got loads of scaffold tubes from work just need to chat some one up for some pipe
We are trying to do it as cheap as we can

 

Don't do it so cheap it blows away and takes all your lovingly grown plants with it

Plenty of people have blagged a greenhouse free off Freecycle, or a nearby neighbour who no longer has a need for theirs ... just a thought, but glass almost certainly banned on your allotment, but might be some tunnels going begging near you too ?

 

Put an ad on freecycle for unwanted 12ft or 14ft trampoline frames, you`ll be surprised how many replies you get 1 frame = 2 galvanised hoops that`ll last for years.

 

Good idea if I can not get hold of some pipe I might look in to the trampolines

 

Make sure you use "anti hot spot tape" on the scaffold tubes, the tubes heat up in summer and help to degrade the plastic cover.

Make it as tall as you can, 6ft is okay...7ft is better for crops such as tomatoes.

Make your doors are wide enough to get a barrow in and out as you will need to change the soil every few years

If you can, dig the beds first before building the tunnel as its hot work doing it after...and more chance of putting a fork through the plastic.

Take time to choose where you put the tunnel, you want to site it where it can best get morning sun in both summer and winter (winter sun has a much lower angle).

You will find this software useful to help with site choice. Its free..

http://photoephemeris.com/tpe-for-desktop

Using this software you can zoom into your plot on a sattelite map, then change the dates and it will show you where sunrise will be at any given time of the year...allowing you to make the best choice you can to get that all important first sun of the day (to start heating up the tunnel)

Good luck!

Steve...

 

All excellent points Steve

Just to add: in my case the ground, inside my greenhouse, was rock hard "afterwards" too - from walking on it during building, and because it had not been recently dug. It would have been easier if I had loosened it before building

For a tunnel does it help to have prevailing wind blowing "in" the door - to help cool it in Summer?

 

For cooling I just open the door, my doors are nearly full height so opening the door allows heat to escape. I would rather be set up to gain benefit from the morning sun than any prevailing wind. If you cant heat it up, you wont need to cool it.

So far I only have doors at one end of my tunnels, I will in time fit doors to the other ends too, which if both are opened I'm fairly certain that will create a "through" draft to aid cooling....but I have not needed that so far.

Steve...

 

Thanks guys for your tips I will deft make shore door is big enough for a barrow good point as for sit it will be on the top of my plot and bottom of dans the sun will go right over the side of it and down the other as is east to west so should get plenty of light

 

Have you got mains water on the site? I haven't, so my tunnels are located as close as possible to where I can park my vehicle full of water containers.

 

Yes mate we have got mains water and right at the side of the plot