Over here, extra bottom space in hives that have deep bottoms is taken care of using a removable
buildstop. The bees sometimes build comb underneath the buildstop, but it's easier to remove from there than having to trim it off the frames.
What is the other flaw that you referred to?
There are several and the hive is going to get a bit of a re-build this year once I can get the bees out and into another hive. These are the principal ones:
1. The mesh floor sits in a 50mm frame but I put the mesh on the bottom of the frame when I should have put it on the top - hence I created 50mm of space below the frames. The fact that the floor of the hive has a step down to where the mesh floor is means that dummy boards cannot just be straight across the bottom they have to be shaped to fit the bottom of the hive - and the mesh floor bows slightly in the middle so the bees inevitably get past the bottom of my dummy boards. To solve this I tried putting foam rubber on the bottom of the dummy boards and the bees ate it.
2. The mesh floor frame clips on to the bottom of the hive and the idea was that it could be unclipped and would just drop down onto the two cross rails of the legs and then simply slide out from the hive. Because the bees build free comb underneath the frames and the side rails of the legs are too high I can drop the floor but I can't slide it out as it would slice off the comb on the bottom of the frames.
3. There is a lip on the edge of the mesh floor frame that locates the floor in the bottom of the hive - bad idea - the bees propolise it and stick it in place and also the hive has distorted slightly so a crow bar is needed to get the floor back in place. Lesson learned - never have lips on bee boxes where the bees can get at them - flush fit every time. I wondered why bee boxes just sit on top of each other ? ... now I know !
3a. Also this lip is not quite aligned and at the far right end of the hive the last couple of frames sit on it and are lifted up slightly so the crown board is pushed up (Not a problem as they have never got to 27 frames yet !) - I just don't put the frames in at that end of the hive and fill the empty space with insulation - but it needs resolving.
4. There is no easy way of putting supers on this hive ... I think that a clip on roof would solve this problem but I really like the fact that I can hinge the roof up for a quick look through the crown board. Rock and a hard place on this so - still thinking.
5. The 'ventilation' holes around the bottom of the hive were put in before I decided on a full mesh floor and not a solid one - the bees have covered the mesh on the inside of these with propolis so I reckon I might as well just plug them up.
6. The frame hanger in the roof impacts on the 100mm of Kingspan I like to have in there over winter and the roof won't close so I have to unscrew the hanger and take it out in the autumn and put it back in the spring when I reduce the Kingspan down to 50mm. It's not a problem just a PIA and I don't think there's much I can do to change it. (I'm thinking about a frame hanger that is outside the hive that is mounted on a stand - so I can use it on all my hives - watch this space !).
Other than that it's nigh on perfect (for me !). Bearing in mind how the hive evolved from a Top Bar Hive and my lack of experience four years ago it's not been too bad but you only find out what works when you start using things - particularly when you are intent on reinventing the wheel !!
Oh ... and I will need a fork lift truck and Pickfords to move it !!
You will see what I mean above from this sequence of photos ...
https://www.flickr.com/photos/99514363@N06/9401432181/in/album-72157634865981506/