Space for bees inside the entrance

[Hoosier]

My five tbh's all have an upper entrance on the front. Inside I will have sixteen 1 3/8 brood chamber bars that are stained on top and fifteen 1 1/2 unstained bars for honey.
What I don't understand is:
If the first brood-chamber bar is filled on both sides with brood/honey/pollen/whatever, how do the bees move around inside once they come inside from the entrance?
I am thinking about putting a semi-permanently-affixed, 3/8-inch-wide "bar" against the inside front to provide space for them to move around easily. Is that a dumb idea?

[Grieth]

I don't have a top bar, but I did add a slatted bottom board.  At last inspection heaps of bees were hanging out under it. but, No burr  comb was built there.  Seems they enjoy the space when the hive is busy and full of bees.  There are posts about this idea of a slatted bottom board.  Good luck.

[Hoosier]

I don't have a top bar, but I did add a slatted bottom board.  At last inspection heaps of bees were hanging out under it. but, No burr  comb was built there.  Seems they enjoy the space when the hive is busy and full of bees.  There are posts about this idea of a slatted bottom board.  Good luck.

"... and why the boiling sea is hot, and whether pigs have wings."

Thanks, Grieth, I don't know what a "slatted bottom board" is, but it's good to know there was no burr comb and their liking the additional space in which to hang out.

[bulldog]

on each of mine the front panels are 3/4 inch taller than the sides and i glued a strip of 1/4 plywood to the front panel ( on the back side of the panel, facing the inside of the hive) of the hive, which gives the bees an extra 1/4 inch of space to move around on the front side of the first comb. if you want to leave them a top entrance you could always glue two short pieces, one on either side, leaving the middle open for the entrance, which would still give the bees that extra space. otherwise they may not center the comb properly on the first bar which coud cause them to mess up every subsequent bar.