What is the material used for drop ceilings? I have done some searching here trying to see if I could find a solution to my problem but then after seeing different topics, I became unsure of what people even call this stuff. Years ago I thought it was called celotex but I am not sure? Anyway I have a few water stains and painting is out of the question because I only have three stains and several squares. I have seen a product you can spray on them for water stains but have not heard or read as to whether or not it works. Also saw here on DIY that someone had used a 1/2 bleach 1/2 water solution on something called "popcorn" ceiling but again, don't know if this is what mine is called. I would just replace the squares but they are in my basement and there is only about a 3 inch clearance from the floor joist so I do not think I can get them out without breaking them and getting new ones in without breaking them. Thanks Much!!

I have redwood paneling throughout livingroom and family room. It has never been painted or stained. However, it is 50 years old. It is a little dull and in places where pictures were hung or shelving placed, the wood is discolored. Is there a way to bring back the paneling, make it brighter, even out the color issues? For instance, sanding? or would i just be wasting my time doing anything to it? Thanks Bryan