Zandronum

I am having trouble figuring out a way to add a door to a 3d building. I have the walls raised from the floor and I am using a solid 3d floor as a roof but I can seem to find a way to make a door for the door slot. I tried making another 3d floor where the door slot would be and giving the 3d floor an action of raising the floor and lowering it to simulate a door opening and closing but I get a really weird glitch where the 3d floor goes through the ceiling of the actual map.

How do I make a door attached to building with a 3d floor as the ceiling?

make the door go down or make it a 3D floor and open it with a script.
sector_raisefloorandceilling of the dummy sector and lower it via the same method.