Re: Roof - open to the outside, or not?
I always scavange plastic cardboard political signs after an election (with permission from mostly winning candidates ). I use pieces of that cut to fit over my hives. Then i use plywood, or any other scrap lumber, then rocks or brick to hold it down. The lumber distributes the weight to minimize cell crushing in the plastic cardboard, which provides waterproof insulation for the roof. When placing it on the bars, I slide it across the bars to dislodge any bees, who quickly move. Got that advice from McCartney Taylor. I also use it as the roof over the top bars in my swarm traps stapled to the front and back of the trap. Keeps the bars down and the rain out.
TxBeek. KTBHs. Victoria, Tx. along the Gulf coast. Zone 9b.
Treatment free bees from traps and cutouts.