[Uffda]

Hi,

I was looking to build a homemade greenhouse / polytunnel.  I've been researching polythene plastic sheeing but am not sure what gauge is suitable.  There seems to be at least 125 or 250 microns.
Any advice on the most suitable will be very welcome.

[mumofstig]

Proper polytunnels are covered in 150 or 180 microns.

I've not used this site, so don't take it as a recommendation, but look here
http://www.premierpolytunnels.co.uk/replacement-cover.asp

[grinling]

my local garden centre sells it.