Originally Posted by grahamlthompson:
“I wouldn't risk it personally with a 50" Plasma especially if you can avoid it anyway. Why take the risk ?”
Graham is right, I had assumed it was a LCD when I gave my advice but the OP does say it's a plasma, so don't take the risk of laying it down.
With fixing I always go for the belt and braces approach when hanging something heavy on the wall as it is not much of an effort to drill a couple of extra holes for the sake of peace of mind.
Originally Posted by artnada:
“Isn't putting a TV above a fireplace the worse place to put it? (If you use your fire that is). All that heat rising directly into it won't do it any good.”
But in a lot of cases the only place you have to hang a large TV in the room (the height may not be ideal either). Worth checking beforehand with the fire on how hot it gets. Usually if you have a mantlepiece above, the shelf provides a degree of protection from direct rising heat.