I have come to the point I dredded when I first bought my tunnel, I thought I would get one twice the size I thought I would need, but now realise I should have got one 4 times bigger. my question is has anyone extended a tunnel without fitting a complete new cover, is it possible to join an extension to the original poly as it's only 3 years old.
The moral of the story is if you are going to get a polytunnel get the biggest one you can afford then get a loan and get one 4 times bigger!

You don't say the dimensions. There is nothing to stop you extending with more hoops but you will have to buy a new long cover, joining covers could be very difficult as no glue will hold on polythene. If you extend don't go beyond 64 ft. as that is the optimum for using standard rolls of polythene, also ventilation gets very difficult the longer it is, unless you go for side vents which gets difficult and expensive. If you have the room you might consider using the small one mainly for propogation and buy a bigger one as well. I find on examination of costs that doors which are useful can be the most expensive item on the shopping list.Width can be very useful, 18ft has advantages over 14 ft. My suppliers have been Fordingbridge (commercial sizes) and Northern Polytunnels, most firms will sell the seperate components.
I have got 4 permanent and 3 mobile tunnels, not getting any more!
Allan

agree with allan on this one we bought a 14 x 65 (worked out as the cheapest per sq ft) and errected it as two 30 footers. having two shorter tunnels helps with the ventalation and the separating of crops which prefer different conditions , one tunnel can be kept humid and the other on the dry side.

Thanks for the info fellas, At the moment I have a 14ft by 30 ft but have room to go another 30 feet.I think Richards idea of two seperate tunnels is the way to go, an end to end gap of 6ft and a 24ft tunnel methinks.
thanks