On 21 Sep, 22:37, "Dave Liquorice"
wrote:
On Sun, 21 Sep 2008 13:54:03 -0700 (PDT), Adam wrote:
Thanks, that's only 30cm wide, but my concrete slabs are 40cm across.
Presumably it's a problem if there's a gap in the DPC?

You only need the DPC between the timbers and the slabs not over the
entire surface of the slab.

Sure, but there'll still be a gap, unless I'm missing something
obvious. See my piccy:
http://www.snowstone.org.uk/temp/plan.png


Later, Phil P wrote:
Personally, I wouldn't use anything underneath timbers in a situation like
this - it merely holds any water in place, right where you don't want it -

This seems like a good point. There will be rainwater above the DPC
and damp below the DPC, so what's the point in it? Why not just lay
the joists directly on the concrete?

Thanks a lot for the helpful replies so far
Adam