We want to completely cover our gas fireplace with a new tv because we never ever use the fireplace.

I'm thinking of covering the fireplace with plywood by screwing the plywood into the drywall mantle and supporting studs, sides and top. Then I would attach a plasma mount to the plywood only (and hitting no studs).

Will this be strong enough for a 50-60" plasma tv (between 90-140 lbs) if I use 2 pieces of 3/4" ply (glued and screwed)?

More than enough as long as the plywood is secured properly to the mantle.

Excellent. Thanks for your reply, mayhem13. :)

Now, do you think 1 layer of 3/4" ply would be strong enough? :rolleyes:

Or, should I stick with 2 pieces?

1 would be fine....try running a piece of hardwood like 1x2 horizontally from mounting hole to hole glued in place to stiffen it up.....nice theater by the way. The screenwall turned out really nice.

Thanks again, mayhem. Good tip with the 1"x2".