In message , john west
writes
We bought on of those Gardman plastic Greenhouse/polytunnels about a
year ago.

Those familiar with them know that the entrance is two full height
Zips, just like on a camping tent.

The Zip is broken and was never really strong enough to be up to
repeated use.

Would anyone know of any kind of fastener i might replace the Zips
with, hopefully keeping as much as the warmed air in as possible when
they are closed.

I'm not inclined to, or skilful enough to sew in another zip and the
only thing i can think of so far is about half a dozen adhesive backed
Velcro strips place horizontally.

Grateful for any other suggestions..... thanks.

Zips seems a bit OTT for a polytunnel.

Last one we had here the entrance was two timber uprights with the
polythene cover secured with staples.

The door was a strip of polythene secured at the top, slightly wider
than the entrance and tacked to a series of battens. The battens were
pierced at either end to take cords attached to the top and bottom of
the doorway. A third cord fixed to the middle of the bottom batten
passed through an eyelet at the door head could be used to adjust the
opening to control ventilation.

Stagnant air is not good in a greenhouse.

Biggest problem is when the Sun heats the metal frame and destroys the
plastic cover where it touches.

--
Tim Lamb