[springy]

Hello, I am a new member. I am the Chair of our local Community Allotment (9 plots) and we want to erect a good size polytunnel which will stay put in strong winds. We have identified a sunny but sheltered corner to place it in and we are thinking of putting tough membrane down first then placing the polytunnel on top of that. Does anyone have any advice on the best membrane to use and the best way to anchor the polytunnel to the ground?  Many thanks and happy growing!

[Eblana]

I bought my PT from first tunnels and they do anchor plates which have worked well for me, I also dug a 1.5 ft deep trench all around the tunnel and put the polythene down into that and back filled with soil.  Both of these have kept the PT secure for 4 years now.

[springy]

Thanks for the advice - I will check out first tunnels

[Goosegirl]

If you can, site the pt so the entrance isn't facing the direction of your prevailing wind.

[Kevin67]

First Tunnels are amazing - with a price tag to match.

I have found shiny, new things tend to get vandalised and so I use stuff that works well but doesn't attract attention. Also, it doesn't break your heart so much if damage does occur.

With that in mind I have a 20' x 10' diy pt that works very well. Consider having high sides for more working area and I used just 4 "dog stays screws" from a pound shop and my pt has done well over some very fierce winds indeed - and I'm on an exposed site.

You will need to consider automatic ventilation and automatic irrigation - without these your efforts will get burnt as you cannot reply on someone to do both on hot, sunny days - and it takes just one day to severely affect plants inside a pt.

[brianbishop]

I also used scaffold planks bolted to the P/T frame to help weigh it down and make raised beds.
Bish

[adri]

I bought ours from Citadel.  Set the base pipes into a barrow load of concrete for each then used a base rail.  For the floor I put down weed suppressant fabric as bought from ebay and then cut holes for the 8' by 4' raised beds made from scaffold planks.  The cut out bit from the fabric sits nicely in the raised bed when the bed is not in use.  On top of the fabric I've spread MOT (like a cheap chippings).  All works fine so far.

Adri

Would be interested to hear of automatic ventilation options as that was the only bugbear this year...

[Kevin67]

The only one I've come across is a wooden/plastic frame with a bar that opens according to temps. Quite easy to diy....

[Plot46]

Citadel delivered my PT yesterday, so guess what I'll be doing next week.. as for anchoring after it's all setup I'm dropping a spade or two of concrete around all the plates. A friend on our lotties as done this and his PT is rock solid,  another PT a few plots over without any concrete which I looked at, wobbles like billy oh..

[adri123]

I'd go for a bit more than a spade or two especially on the four corners.

[Plot46]

Thanks Adri123... it's taken on board.

[m1ckz]

my pt is 4m x2m  green..i dug in 6x6 inch beams all around it to ground level..then screwed the tunnel on to the beams     that wont move