l'm going to be putting some decking down and need to know how much l need, is there any conversion for measuring how many l need so l know how much it will cost. l'm going to be doing the decking 12ft x 12ft and getting the deck boards from B&Q, the size of the boards are (L)2400 x (W)144 x (T)28mm l just need to know how much needed so l can price the job up. If anyone knows that would be a great help, also how much wood l would need to build the frame.