any body know where I can get some cheap 3"x2" for a frame roof on a shed lol

been meaning to bolt it up for 2 years

its a prefab concrete double garage that Im going to make a 16ft x 10ft lock up in me back garden but need to make a roof for it

thinking of a slanted roof also not an apex one so 3"x2" pine or sumink shoud do eh?

already have the base down, had that done 3 years ago