polytunnel construction.

[gensetsteve]

Pick a dead still day and make sure you have no machinery or thisles thorns etc near by if it blows off you can have another go but if it lands on a hay turner life gets a bit more stressful.

[cornish wood burner]

Working for a nursery we've done a few. (Hundred)

First put a pole through the roll then rest the pole on something like stacks of pallets so it can unroll freely.

With a person either side of the tunnel, pull the poly along the length.

Batten one end then tension at the other. Tighter the better.

Next work along the sides evenly tensioning from side to side.

If you are digging in the poly, dig your trench about 200mm deep, put a little earth over the poly,lift,flap to

tension from side to side. Increase the fill, turn poly back towards the tunnel then fill completely.

Tunnel structure is very important and it must be able to take tension along the tunnel length.

[cornish wood burner]

I was looking at 30ft span 90ft long polytunnels recently and saw these guys - firstpolytunnels. No link to me at all. They have a fitting team and this really appeals. I reckon having someone who really knows would save hours, maybe even days on a big tunnel. No idea on the cost of this though.

 

Perhaps I should set up as a tunnel erector advisor. Nice little retirement job. Seriously though it is really quite easy if you go about it the right way. We work on a max wind speed of 12mph for small and 8mph for a large one which I would class as 40 to 50 metres long. Less wind means less pulling so as still as possible.

[tree79]

I've done fair few to

 

Unroll all the poly 1st, if u have a small tower that would be useful.

Keep pulling the poly over the hoops, depending on the type of tunnel you can rest a ladder on the spacers or on the hoops.

Some people tie ropes on to the poly but not had much look with that.

Once you've got a few hoops over it pulls easer.

 

Have you put anti hot spot tape on the hoops?

[renewablejohn]

If anyone wants to learn how to put a cover on a large polytunnel I will be installing a 25 mtr in the next couple of weeks weather permitting and then a 40 mtr tunnel around the 1st week in Sept. First one attached to rails and the second dug into the ground. Quite willing to show anyone but be prepared to work and expect a bit of anglo saxon language.

[renewablejohn]

Perhaps I should set up as a tunnel erector advisor. Nice little retirement job. Seriously though it is really quite easy if you go about it the right way. We work on a max wind speed of 12mph for small and 8mph for a large one which I would class as 40 to 50 metres long. Less wind means less pulling so as still as possible.

 

Your a braver man then me. Has to be perfectly still for me even to attempt to put a tunnel on.

[cornish wood burner]

Your a braver man then me. Has to be perfectly still for me even to attempt to put a tunnel on.

 

Providing you have enough help then the wind can actually help a little. Always pull into the wind and it will lift the poly over the hoops. Our nursery is on a very windy site so very few still days unfortunately. Over 30 sheets to maintain so we have to take our chance when we can. Best to cover at the end of the summer if possible. One less summers UV means virtually another years life from the sheet. We use scaffold tressles to batten the ends. I definitely would not advise unrolling first as that just increases the risk of damage. If you are not pulling into the wind a batten or long handled brush may be needed to lift the leading edge over the hoops.

[renewablejohn]

Having enough help is always our problem we normally manage with myself and the better half.

[richy_B]

Perhaps I should set up as a tunnel erector advisor. Nice little retirement job. Seriously though it is really quite easy if you go about it the right way. We work on a max wind speed of 12mph for small and 8mph for a large one which I would class as 40 to 50 metres long. Less wind means less pulling so as still as possible.

 

This is my point exactly. If you know what you are doing then I am sure it is pretty straightforward. As a first timer I'd be a bit apprehensive about putting up a pretty large polytunnel. Especially if I'd spend a few grand buying it.

[cornish wood burner]

This is my point exactly. If you know what you are doing then I am sure it is pretty straightforward. As a first timer I'd be a bit apprehensive about putting up a pretty large polytunnel. Especially if I'd spend a few grand buying it.

Best piece of advice I can give to anyone erecting a tunnel, is do not underestimate the importance of longitudinal strength.

Presumably most would go for a single span as their first but multi spans are almost as easy, they just have a gutter down the middle supported by posts. When buying you have a choice of fixings and hoop shapes and sizes. It depends on the use required.Trenching works well with the sloping sided shapes, especially if you have a digger of some kind. A tunnel with upright sides makes good use of floor space and gives the chance of good side ventilation. Most aluminium clips are very quick to use but many can cut the polythene if not used correctly. Your chosen supplier will advise on which systems he can supply. Wooden battens are reliable and easy to use, but again practice makes perfect. Its all simple stuff and I'm sure plenty of advice would be given through this forum.