Adrian, it was your build I was looking at thanks for quick response really handy info there! So I will be getting 6 meter lengths so will need 7 x 6 meter lengths of 25 SHS 2mm thick Walls and 3 x 6 meter lengths of 20mm SHS 2mm thick walls. The book says 19mm and 16swg but 16swg is only 1.5mm thick and the coompany supplying says 19mm is called 20mm, I assume this is the metric euro size. Will this be ok? Oh and it does have to be seamless, correct? Thanks Andy for your info too!
