I need help designing a shelf that will carry the weight of a plasma tv approximately 135 lbs. Basically, how thick should it be to prevent sagging? I'm not able to furnish a sktech so I'll simply try to expalin the dimensions.
The shelf will be mounted between two exisiting vertical boards which are each about and 1 1/4 " thick and 8" wide. The horizontal distance between these two is 80 inches. There is no other loading to speak of on these two being a frame around a mirror that forms the backdrop for a liquor bar. I believe they are made of Oak.
Also the weight of the TV will be carried on a TV stand that is approximately 3 feet in length and 12 to 14 inches wide. So the shelf has to be wide enough to meet that requirement but be able to taper back to the upright supports.
"Cleats" could be used to support each end of the shelf and depending upong the thickness of the shelf, I thought of running a "stringer" the length of the shelf for added support.
Hope I'm not confusing too many with these terms but that's the best I can do with a limited woodworkers vocabulary.