On 30 Aug 2017 18:09:47 GMT, KenK wrote:

I have floor vents thoughout my mobile home for a heating system
I no longer use - propane is WAY WAY too expensive. The grill-
like vent covers are a PITA, I too often get a shoe caught on
one. I'd like to replace them with a solid cover but can't think
of anything thin enough to avoid tripping on. Maybe a sheet of
aluminum and file down the edges (bevel them) so there's nothing
to catch on. A better easier idea? The vent holes are about 4
1/2 x 10" so the material should be strong enough to avoid
breaking through.

TIA
If you are sure you never want them again, go under the home, take out
the vent and ducts, put some blocking across the hole and then cut a
drop in filler the thickness of the floor for the top. It will be
flush.
If you ever did want the vent back, remove the blocking and the
filler, reconnect the ductwork.