[wolf1]

I have decided to try and grow as much fruit and veg this year to eat and store i have been looking at polytunnels but the good ones look expensive has any one tried making one from MDPE blue pipe i have seen loads of videos on youtube ect but just wondered if anyone on here has personal experiance with one i am only planning on making a couple 12ft x 6ft ones and some smaller ones at 6ft x 3ft to move around on some raised beds any advise would be great i have a plot which will be ploughed and rotavated once it is dry enough which is approx 120ft long by 30ft wide so hopefully loads of veg and fruit 

[Fleecewife]

I used to make small row tunnels for early protection of outdoor veg, and I'll be giving it a go again this year.  The blue pipe is fine.  Stick a 2' section of cane up each end so about 18" protrudes and push that down into the ground, making the hoop the height and width you want, maybe 3' apart.  Make a series of these for as long as you want the row.  There are various ways to tie it down.  You can run a length of taught string along the top of the hoops, then peg them down with a tent peg at each end.  Once you have put the cover on over this, run a length of string, again holding down with tent pegs, alongside and over each hoop.  When you need to raise the sides for weeding, watering, letting the air and insects in to pollinate, or whatever, then one edge can be slid up to the top, and pulled back down again at night.  I used spare polytunnel cover polythene which is nice and thick, and I don't think it's worth skimping on the thickness you use to save a few pennies.  For the ends, stretch the polythene as tight as it will comfortably go, tie in a bundle at each end and either hold down with something heavy, or use a sturdy tent peg.  I think you can make a concertina type tunnel without ends, then make flat end pieces, but I haven't done that.

For a walk-in tunnel made of blue pipe...hmm.  Maybe someone else has no problem but I would think it wouldn't be strong enough to withstand a strong wind.  The pressure on the polythene from wind is far more than you might imagine.  Think of ancient ships sailing around the world with nothing but a couple of sheets on a big stick and a puff of wind.
Second hand tunnel hoops are frequently available for the frame at very modest prices, then you just supply the polythene yourself (well not quite as there are all sorts of bits and bobs which go to building up a tunnel frame which would have to be sourced in they didn't come with the hoops.

Having said all that, you'll love your tunnels once they're up - they transform growing, especially if you're in an area with plenty of frosts or very heavy rain 

[Mammyshaz]

I'm going to give small ones a go this year to start some areas off with the risk of frost. Thanks for the tips how to do it FW  I have a small 8 x 10 poly and love it. As everyone warned, it is never quite big enough once you start planting  so go for the biggest possible.
Our local allotments have the homemade walk in  blue pipe polys on so you may get some advice from a local allotment area wolf1. Good luck, you won't regret a poly in my experience 

[wolf1]

Thanks for the replies i did think that a walk in one would be too unstable and my field is very open i have decided to do small ones around 3-4 ft high to put the young plants under to get them going and have a go at building a green house out of timber and plastic i can anchor it down well by concreting the posts in i built a field shelter years ago and that is still standing strong 

[Bramblecot]

Hi wolf ,
The gardener at the house where I work has made a couple of walk-in tunnels using blue pipe supported at strategic points with timber.  Knowing your talent, you will be able to knock up something very similar.  He has also made them using heavy grade close netting which protects from birds/butterflies, and raises the temp slightly but does not overheat.
By the way, the panels are in good use- part of a new chicken run

[wolf1]

Hi Bramblecot    hope your all well glad the panels are doing well i have decided to build a greenhouse made from timber and plastic im making it very heavy duty so hopefully it will stay up in the bad weather and will make some smaller tunnels from the blue pipe and plastic to move around the field 

[cloddopper]

I made four hoop tunnels of three blue 22 mm Alkethene water piping about five feet long by four feet wide in  1996. Getting the cross over braces right is a must  you'll also need to  use poly tunnel UV resistant sheeting for it happened  be a hot year & I'd used some clear heavy duty polythene sheet  , the plastic tubes softened and dropped /drooped a lot the clear poly sheet went brittle and quickly became holed & useless.
 They were not useable the next year .
You can sometimes buy used industrial polytunnel sheeting on the internet  ... not always on eBay , as  most big commercial growers do a planned time sensitive renewal program to ensure that they will always have sound useable poly tunnels.
 
 Had I to do it again I'd slip calculated lengths of 1/2"  black mild steel bars inside the actual hoop tubing and brace tubes Then bend  the hoops to shape over a concrete & rubble filled 45 gallon steel drum former etc.
 I'd get the cross brace support brackets made in steel tube and welded up so the ends of the brace bars could be covered in insulating tape and then forced in the cross pieces  & also drill the plastic tube to take a small self tapper to retain the cross piece supports in place . Putting in the steel would also give a lot more anchoring weight and help the hoops retain  shape when / if you move the tunnel around .