Hi Tom and other Bee-L readers,
Tom wrote,
"If I understand correctly Paul has no floor or no open mesh floor. How can
the bees defend such an opening especially against wasps in the autumn?"

I have cut the solid floors out of 5 of my hives. The floor now consists of
a landing, with an opening of 20 x 365 mm (which I can reduce in winter, or
if wasps become a problem) and a 45 mm high surround. (no actual floor or
mesh screen).
This floor, the hive itself, is supported on a 260 mm high fully enclosed
plywood base which is open to the ground beneath.
This means the bees only have to defend the same sized entrance as a normal
hive entrance.
In spring, the bees have built drone comb down into the sub-floor space when
there is insufficient space in the supers. The enclosed-base has a rear
opening door through which a mite counting drawer can be slid for monitoring
natural mite fall and for access to the bur drone comb which I cut off using
a long handled 'chistle' tool. This removes the varroa mite trapped in the
drone comb. The rear opening sub-floor door can also be left open during
honey flows to provide through ventilation. Bees will then enter and leave
by both openings.
This type of hive closely approximates the natural 'hollow tree' feral
colony. Condensation (water), mites, bee crap, etc all falls to the soil
below and the decomposers recycle it. (A pity I can't adapt the concept for
here at home!)
Cheers Paul b. Auckland. New Zealand.