I have just finished a 3x3 shed which I layed on 600x600x35 mm concrete slabs - 25 of them (26 including the one I dropped and cracked haha). I slopped them away from each wall to hopefully flow water out.
I put the whirley bird sprinkler on the roof after I finished, and only water that got in was at each corner and it ran straight out of the slabs.
Only winter will tell the real situation
With regards to extending the life of the deck, Do the large nature strip last, which is very slightly sandy - tends to get a lot of the grass off. After I drain the fuel, I tip the mower on its side, sweep and wipe the grass out, then use the leaf blower and blow over it and through it. Empty the catcher, blow that out as well. The catcher either ends up on the shelf, or ontop of the mower (handle bars up so the snorkel isn't buggered). They are now stored in a (hopefully) well draining shed that gets morning and afternoon sun, day shade, and reasonable ventilation.
I am like Ted Bulpitt and his Kingswood.
The Victa, your not taking the Victa, I just ajaxed the hubcaps
