polytunnel cover

Gaothfar

Hello,
Has anyone ever successfully glued sheets of polythene together?
I need to replace the cover on my polytunnel and the price from the manufacturer is 150 euro but the same stuff (polythene) is available from the local builders providers for 17 euro. Quite a difference!
The only snag is the cheaper stuff comes in two pieces. There must be something that will glue two sheets together. Anyone know what it is?

pauln

Polyeurethane glue seems to be what's need see here. I found that lot the other day while googling for a Irish supplier. I'm also looking for some, ideally a local supplier of polytunnel plastic down the Waterford area. Who do you go to for it?

I've used the stuff from the hardware store before outside and the problem with it is that it isn't UV resistant and tends to get brittle after exposure to the sun for prolonged periods.

P.S: Don't need it for a polytunnel as such, I'm building one of these.

Macy

pauln wrote:

P.S: Don't need it for a polytunnel as such, I'm building one of these.

Great plan, especially if in conjunction with a standard heated greenhouse for over wintering/ early starts of seeds...

Edit Actually a great site for all things wood. Lots of projects to plan and never start

pauln

Macy wrote:

Great plan, especially if in conjunction with a standard heated greenhouse for over wintering/ early starts of seeds...

Edit Actually a great site for all things wood. Lots of projects to plan and never start

Ya it looks like a good one, I spent awhile looking around for something and this one stood out. There's two pics of a finished one here and here.

Planning on using it to plant vegtables in just to give things a bit of a boost. Just finished the ground works for it today, needed to flatten out a bit of a hill for it.

Anyone got a lead on polytunnel UV resistant plastic?

Gaothfar

Thanks Paul. Polyurethene - I'll carry out some experiments and let you know.
I get my polythene from the local builders providers - Cahills or Coens of Gort, Co Galway but I'm sure it is available wherever cement is sold. If you check where they keep the DPM (damp-proof membrane) which is used in building, you will find they have grey or clear. It comes in different thicknesses. I use 500 gauge.
As regards UV, at 34 euro against 150, I could afford to replace it a few times. By filling the trench with sand instead of soil, the old cover comes out without too much labour.
Also, as regards that Texas greenhouse, I would make the frame (without that fiddly two-tier roof) and cover the whole thing outside with plastic. Then why not go the whole hog and make a polytunnel. I've heard of it being done with hose-pipe for hoops (heavy-duty black ones available from - you guessed it - builders' providers.)
Good luck with your constructions and keep the rest of us posted. Saves me having to make ALL the mistakes myself.

pauln

I reckon I'll be going with the builders plastic too at those prices.

I saw an idea for a polytunnel which involved setting some re-bar in the ground and bending some PVC waste pipe between them, looked simple enough.

I went for this one in the end because it just sort of suits where I'll be putting it and the size I'm looking for. It looks like a interesting project too.

The roofs a little over complicated alright but not to bad to put up and I like the idea of the windows up top to leave out some extra heat in the summer.

Edit: I've started a thread on another idea I was having to do with the greenhouse here and would welcome comments.

Macy

Polydome is the only supplier I've seen of the UV stablised polytunnel plastic.

Instructions for a home made polytunnel here Pauls Garden World. Depends on the proposed site I suppose, but the poly greenhouse would be a much stronger structure.

JPFP

Gaothfar wrote: »

Hello,
Has anyone ever successfully glued sheets of polythene together?
I need to replace the cover on my polytunnel and the price from the manufacturer is 150 euro but the same stuff (polythene) is available from the local builders providers for 17 euro. Quite a difference!
The only snag is the cheaper stuff comes in two pieces. There must be something that will glue two sheets together. Anyone know what it is?

The dearer stuff has a 5 year guarantee against UV degradation - the cheaper stuff lasts about 6 to 9 months exposed to sunlight. The dearer stuff is co-extruded (that is 3 layers of film joined together), each layer giving different qualities to provide improved growing conditions and maximise strength/light transmission - the central layer for example is EVA which helps reduce heat loss at night. The dearer stuff is 200 micron in thickness the cheaper stuff is 125 micron. One is for polytunnels the other is for building - different products for different jobs. The price should give a clue that they are not the same at all. When you have replaced the cheaper product maybe 10 times during the life of one dearer sheet (after finding a way to stick the cheaper product toghether 10 times) and spent about 5 days extra in labour - and your plants will not have grown as well at all, will the penny drop?

Builderwoman!

High Bank in Kilkenny or Decker.ie are suppliers of polytunnel plastic. I think that if you use hot spot tape with their plastic you should get 7-10 years out of the plastic and I don't think you'll get that from regular builders plastic.