I'm going to disagree with what rickygsg has said. You don't have to worry about your surface being level, but it MUST me flat. You don't have to be building museum quality to worry about a flat surface, you need to worry about it for any model. If your surface isn't flat you can build a warp into you wing and fuselage structures. rickygsg, I'm glad that you haven't had any problems, but you've been lucky. I've seen what can happen when wing is build on a surface that's not flat, and it wasn't pretty. The wing had so much warp built into it that we couldn't straighten it, but rather the owner had to trash the wing and build a replacement.

If you care about the plane that you are building, please make sure that the surface is flat. It's fairly easy to check. Take a 3'-4' straightedge and place it with the straightedge down on the surface of your building table. You will be able to see if the surface isn't flat against the straightedge. Check in several different directions.

I use glass top. Straight and smooth. Easy to clean surface.

Glass top is the way

perhaps i over exagerated a but. my workbench is close to flat but building on a board of drywall on top of the workbench the drywall 3/4 inch thick more then takes care of any flatness not in the workbench. it does flex but not when lyeing on a workbench.

to clarify a bit more i can put a pieace of drywall down on a very uneven surface and putting a strieght edge to the drywall it will be flat...perhaps not level but flat.

I use a Dow Styrofoam board, that is available from a lumber yard. It is about 5/8" thick and comes in 4'x8' size. Make sure it is on a flat surface, like a 3'x6-8' folding table available at Sams Club or other places.

The hollow core door is a good choice. Just be sure it is FLAT. Being up in the rafters for an extended period of time may have warped it. Driving pins into the door is difficult at best. I used a product called Celotex for years. It is made of cardboard but is dense enough to hold "T" pins quite well. Another product is Homasote which is availabe at Home Depot or Lowe's. I've never used ceiling tiles so I can't offer much info on them. Take your door and overlay it with a piece of either Celotex or Homasote. Overlay that with your plans and cover them with waxed paper and you're off to the races. Good luck. NOTHING beats flying your own creation

The hollow core door is a good choice. Just be sure it is FLAT. Being up in the rafters for an extended period of time may have warped it. Driving pins into the door is difficult at best. I used a product called Celotex for years. It is made of cardboard but is dense enough to hold "T" pins quite well. Another product is Homasote which is availabe at Home Depot or Lowe's. I've never used ceiling tiles so I can't offer much info on them. Take your door and overlay it with a piece of either Celotex or Homasote. Overlay that with your plans and cover them with waxed paper and you're off to the races. Good luck. NOTHING beats flying your own creation