I have no experience of polytunnels but, looking at the photo you've posted, it looks to be made of very thin material? I have seen a few polytunnels locally and they are made of much thicker material that can't be seen through. Although I have noticed that even they look a bit raggedy by the end of the growing season. Sorry I can't be of help. :o)

I think Nariz may have hit the nail on the head, the picture does show a very flimsy structure. A polytunnel should have very heavy gauge plastic to be able to withstand the elements. It is possible to buy replacement covers. You can expect to pay several hundred pounds for a good polytunnel that will last for years.

Our 30 by 14 feet polytunnel cover is 720 gauge UV protected laminated PVC. The last one lasted 12 years although they are only supposed to last 5 to 6 years. Even now the pieces left after the last lot of gales are in good enough condition to be recycled into cloche covers.
For a new cover from LBS Plastics along with tape to cover the metal hoops (anti-hot spot tape) we paid 180 pounds (ish). Properly fitted it should (bows to Hubris) last a reasonable length of time, assuming the cats do not puncture it again!

as you have it you could try making it difficult for the wind to get it -- maybe trench it and build up the sides with earth-- burying the edges-- I don't know how fesible this is but some tunnels use green mesh -- could you cover it with that and peg it down-- it may help the uv too.....no idea of the cost though

Pam the only way it will work well as a polytunnel is if the pvc is strong enough - otherwise the UV will cause it to breakdown rapidly. Our son gave Bulba a polytunnel cloche for Christmas 09 and that was pretty much US too. Folk need to accept that you have to pay a reasonable amount of money to get something that actually does the job.

We got burned ourselves saw a polycarbon cold frame in Lidl and need another frame. Up to then we had only used glass. Yes it was cheap and yes it was rubbish... B spent time fixing it again today. The glass ones just keep gonig with the odd broken pane.

A good polytunnel will be of at least 600-and-something guage, but preferably 720 gauge plastic and should last for years. The one shown in the pic looks very thin to me. A thicker gauge polythene is not just stronger but insulates better too.

However, if you've already got the polytunnel, as Pamg suggested you should try to protect it - place it in as sheltered an area as possible. If you want to buy just a replacement cover, lots of companies, eg First Tunnels, sell these separately. Hope this helps. :)

thanks so much,i will pass this onto dad,i knew there was something about them as they were only £99,and as i said poly tunnels are usualy a lot dearer,ive got one too and dont know what to do with it now and wil have to think on how to make it stronger,thankyou chris