You would be able to check if this is the case in your home by going up into the attic.
Decorative wood between floor joists ceiling.
You may need to lift insulation or plywood to see the joists.
Floor live load of 40 psf between the kneewalls.
Called a floor covering or finish floor this might be ceramic tile solid wood laminate engineered wood luxury vinyl carpeting and many others.
Owt ornamental wood ties ironwood 6 in.
Lower ceilings shrink the volume of the room to be heated.
Floor covering is the aptest description since everything below the substrate can be considered the real floor in terms of structure and permanence.
Ceiling drywall hides the unpainted unfinished wood of joists beams or the floorboards supported by the beams plus a lot of other junk detailed below.
Ceiling board allows you to heat your room far more efficiently.
Bonus room floor joist selection guide.
Generally floor or ceiling joists run parallel to the rafters.
In general floor planks should be installed perpendicular to the ceiling joists although the presence of a plywood sub ceiling or a layer of perpendicular furring strips will allow you to install parallel to the joists.
Straight gable roof framing is assumed for selection table.
Floor joists and ceiling joists serve similar purposes.
For finished ceilings first disconnect the electricity and remove all light fixtures and other obstacles.
Attic and floor dead load of 10 psf.