[A. Fallowfield]

Is there a really good tape for joining clear polythene sheet?
Big sheets are very pricey, but Wilkos have cloche polythene at a reasoable price. two of theirs joined would be ideal for what I have in mind.

[noshed]

Wilkos sell plastic joining tape I think

[Terrier]

You can buy clear heavy duty cellotape which is meant for repairing broken panes of glass. Also, if you don't mind it being black tape, any farm suppliers will sell rolls of PVC tape meant for repairing wrapped silage bales and that sticks to anything.

[Bluedave]

I would have thought that any sort of duct tape would do the job?

[arugula]

You can buy clear polytunnel sheeting repair tape, its strong if thats what you need.

[pedro]

try allplaz.com  they sell clear tape for just that purpose, I have used it and it stayed outside all winter with no nproblems.

[DD.]

It may well be, but make sure the polythene you but is UVI, otherwise it's not going to last.

[pedro]

It may well be, but make sure the polythene you but is UVI, otherwise it's not going to last.

Yes I agree with that. Dont buy any plastics for the plot unless its uv stabilised.
Its unlikely to last out the year without falling apart.

[A. Fallowfield]

What I've bought is two Wilko's poly-sheets. I made a mini greenhouse out of this for my patio two years ago and its still ok!
I have found the stuff I need on the net http://www.allplaz.com/acatalog/Tapes_for_Polythene.html
it's not a bad price until you add the jolly old PP on it, but at least I know what to look for!

[Trillium]

Duct tape won't hold up to the heat of the sun and will quickly fall off and defeat your efforts. There is a special tape for greenhouse/hoophouse poly but I don't know who would carry it in the UK. It's UV and heat resistant.