over kill?

[GLOCK]

If i put a slotted board on top a screen bottom board is that to much ventilation or should i just use the screen bottom board.
Thank you. 10 days till i get my bees.

[Michael Bush]

The slatted rack will make less ventilation than a SBB by itself.  Why do you think it would make more?  It baffles the air a bit and slows it down.

A slatted rack on a SBB is fine.  You may want a tray in the winter, but that's another matter.