Hi chuckanw,

Yes, there is a work around.

Draw a floor, set the properties, etc. and then, right click in the floor-->Move to Plan-->Deck (or landscape, or...). Make the same process with the ceiling and move it to a different tab.

If you moved the floor to the Deck tab and the ceiling to the HVAC tab (for example) hide the HVAC tab in the Deck tab and the Deck tab in the HVAC tab. To do this, click the small arrow next to the title of the tab so you can view or hide other plans.
In this way when you are working in the "Deck"tab , the floor of the room will be present but the ceiling will not, so you can select it and change it without problems. The same for the ceiling.

In Platinum, the tabs have the same color, but in AS18 and up, the tabs have different colors

Hope this helps

Patricia