I had the 12x20 for almost 4 years and it held up good, like Sasky said just keep the snow off it and anchor it down good.
I made a 2x6 frame and fastened mine down to that with four pieces of rebar about 2 feet long through the 2x6 and driven in the ground on each side. It all held up until we had a hurricane and it kind of mangled it
I now have another, I got mine on sale for $150.
I made a 2x6 frame and fastened mine down to that with four pieces of rebar about 2 feet long through the 2x6 and driven in the ground on each side. It all held up until we had a hurricane and it kind of mangled it