"tjr" wrote in message
...

Hi All,

I'm about to build a greenhouse on some existing paving slabs. The
slabs are very firmly laid, but are not perfectly level. I'm building
a 4' x 6' greenhouse and along the 6' length the slabs are virtually
level, but along the 4' length it drops by about 15mm.
I'd appreciate any advice.


I would not worry about so little fall.

Mike