roost size - spacing and dimensions

Hello Folks,
I hav the walls of the chicken coop done now, and want to design
roosts and laying boxes.

I have read much, perhaps too much!

So, now I am confused.

What should the dimensions of roosts be - figuring standard size
Chickens?

Could one use the 16" centers between studs in a wall as width
dimensions for neting boxes? this with a piece of 1/2 inch osb should
leave a 13" wide box - The question is what depth and height then?

Advice welcome.
Thanks,
Martin

We have two age groups of chicken. They are four weeks apart. So far
they are living in seperate coups, but we are thinking about mixing
them together. Would the older ones pick on the smaller younger
ones. The youger ones are about 8 weeks, older 12 weeks. Any
suggestions?

thanks.

A couple of days ago it got really hot and we lost a chicken due to
heat. We tried saving the 2nd one by keeping her cool and regularly
feeding it electrolytes. She is showing progress as she has started
to eat and drink on her own, and is also now moving and socializing
with other chicken. However from time to time she stops to breathe
labourously. We are going to the vet soon. In the meantime, any
advice what might be going on with her breathing? or what more should
we do?

thanks.

Is anyone using diatomaceous earth ? for worming. dorothy