The wall is 2 3/4 in. thick.It appears to be drywall.I drilled a hole and scraped the walls of the hole with a house key."Chalky" material appeared.I would like to install a cantilever t. v. wall mount that weighs 45 lbs. on the wall.The plasma t.v. weighs 80 lbs.Any suggestions appreciated .This building was built in 1963.It is 17 floors in height.The t.v. is on the 2nd floor and on an inside wall separating the living room from the den.Thanks.Doug O.
from your description it sounds like it might be plaster.I don't know about you but I don't have several thousand dollars to toss away if that TV falls off the wall and a plaster wall or even drywall is not going to support 125 lbs of weight.I would cut out a section of where you want it and find the studs then add some bracing and cover it up with a section of drywall tape it mud it sand it smooth and paint it then put up your TV into the bracing
You want to screw that wall mount into studs, plaster won't support that for long.
When I hung a tv above my fireplace, there weren't any studs. My walls are drywall, but there's only 2" between the drywall and cinder block for the chimney, they didn't put any studs there when the house was built. I cut out a hole big enough to fit studs in sideways, and re-drywalled.