Another TV mounting question

[fastalkintn]

I'm about to mount a tv in the bedroom of our 27 rkss and have a couple of questions. I have located the backer which is on the outside wall. The shortest screws I can find that fit the mount are 1 1/2" long, when through the mount they have 1" that will actually be in the wall, is this to long? I am terrified that I will go all the way through. Since there is a backer board do I still need to use wall anchors?

Thanks to everyone in advance for your help.

[myxkp]

Ouerbacker wall is right behind the TV in the living room so no chance of going through to outside

[fastalkintn]

Originally Posted by myxkp

Ouerbacker wall is right behind the TV in the living room so no chance of going through to outside

Mine is on the street side outside wall.