Valances and drop ceilings - Model Railroader Magazine
John,
I completely agree with Karl about being sure the ceiling is securely attached to the floor joists above. My ceiling has suspension wires every 32" (My floor joists are on 16" centers). The suspension wire is approximately 1/8" in diameter. Don't use the thin wire that you find at Home Depot or Lowes. I had my ceiling installed by a professional and when I told him what I was going to hang off the ceiling the above suspension system was what he suggested.
I think you'll find it easier to install your drop ceiling all the way to the walls of the room rather than bring it just to the front side of the valance. This has the advantage of giving the edge of the ceiling grid good support by being attached to the wall studs and when it's finished, the white ceiling tile above the lighting fixtures will act as a reflector of the light down onto the top of the benchwork. By having the ceiling go all the way to the wall, above the valance, you have more flexibility in how you treat the valance at corners, eg. square corners or rounded corners. I'm using some of both. Another reason I chose to take my drop ceiling to the walls was that in the future the room could revert to "normal" use under a new owner. I guess I'm too considerate.
I think if you look at Barrow's article again, you'll see that he does not use plastic diffusers in his new lighting configuration. Using one would hid the light fixtures but, at the same time, would also reduce the amount of light reaching the bench top.
I strongly recommend using the GE Chroma 50 (Sunshine) fluorescent tubes he suggests to get good color rendering.
Where are you located?
Bob
Bob