"Thomas D. Horne, FF EMT" wrote in message

BBQ grills that are listed for use in or on a dwelling will not except any
tank larger than 10 pounds without an adapter. That is done deliberately
to prevent the use of the larger propane cylinders inside a building.
Most regular BBQ grills are not listed as gas cooking appliances that are
suitable to use in doors.

You are talking about the tiny grills that are about worthless. That is not
what the OP is looking for and really has little to do with the subject of
use on a deck. Those things are table top units that use the disposable
tanks. Real grills use the 20 pound tanks.