On 10/9/20 7:21 am, Chris Bacon wrote:
On 09/09/2020 21:48, Brian Gaff (Sofa) wrote:
So were you economising in concrete?
Â* Brian


No. There's probably rather more than 4.5 cu m there. I measured it
carefully, and the base is spot on. I had previously read (somewhere)
that the base should be just larger than the building. mCormaic's site
says 150mm. Lidget Compton say 3" larger all around.

The question remains unanswered (apart from "sound"), unfortunately. If
I need to do anything about it, I would rather know now, when I have
some work to do welding up trusses, which will take time, during which
more concrete could set.

What I am worried about is that the edge may give way, or the keel
deflect and "rotate".


Any reason why you can not make the shed smaller?