Shed build #777

[muzzza]

Craig, Leaving a gap will invite snakes, mice, geckos etc. I would not be leaving a gap at all. Best practice is to lap the cladding down the side of the slab min 50mm. Between slab edge and the cladding, I normally specify a "Z" type flashing that runs the perimeter of the slab. This flashing closes off the corrugated ribs in the wall cladding to make it pretty much vermin proof.
Sloping slab will be a pain the arse in every way, other than when you are hosing ! ( hosing is for cowsheds !! IMHO ) Can't imagine you will get that much crap on the floor !?. Wash down bay with catch drains outside entry doors would be my idea. Interesting that you have embedded steel portal frames directly into bored concrete piers. Normally we would set bolts into reinforced pier to enable adjustments / levelling.
Trust that a good bitumen based paint was used on steelwork in contact with concrete. Muz

[Jaydee]

There are 2 thought about pouring the slab after the walls are fitted or before.
As I have moved house I need to build a new shed as well. My old shed had the concrete poured after which filled all the corrugation and keeps out all the bugs and spiders etc. The concrete was screened to a waterproof smooth finish and sprinkled with black oxide and neat concrete. It won't soak in water or oil etc. It's easier to sweep and hose out. Even though it's level, with a high pressure cleaner, you can just keep spraying towards the door and it won't leave much water on the floor. Any small puddles can be swept away, and it will dry overnight.
The disadvantages they tell me is that the sheets will rust. My old shed was 30 years old and didn't rust. Maybe the steel these days isn't as good as they won't guarantee against rust if you pour the slab after the sides are put up. So they suggest the lip that muzza was talking about. The z flashing sounds interesting, I haven't been told about that, as they told me to rest the sheets onto the concrete. But as the concrete won't be perfect, you'll still get gaps. So I might consider the z flashing. Also interesting about bolting the frame after. Great thread. I wish I could get a shed that big. I need 4 meters high for my hoist. How tall is yours?
JD