There was nothing to stop things from falling into the house. This posed a real problem in the bedroom where bugs and other droppings could mess up your nice clean bed. Hence, a bed with big posts and a sheet hung over the top afforded some protection. That’s how canopy beds came into existence. (gamla sängar med tak på toppen)
The floor was dirt. Only the wealthy had something other than dirt.
Hence the saying “dirt poor.”
The wealthy had slate floors that would get slippery in the winter when wet, so they spread thresh (straw) on floor to help keep their footing. As the winter wore on, they added more thresh until when you opened the door it would all start slipping outside. A piece of wood was placed in the entranceway. Hence the saying a “thresh hold.”
(Getting quite an education, aren’t you?)