I was getting ready to wall mount my new 50" plasma, and I discovered that the studs in my wall are exactly 8" off center from being able to mount where I want to on the wall -- basically the worst possible position. So, I was thinking I could install a couple of horizontal board to attach the mount to (Sanus vmaa18 articulating mount). That way, I get to attach the boards to 3 studs.

1. How do I know how thick the boards need to be to hold the screws so the screws don't just rip through under the weight? Can I use 1x4s (3/4" thick) or do I need 2x4s?

2. Is there a particular size screw that I need to use to attach the boards to the studs?

3. Is the stud/drywall/board sandwich going to crush the drywall with the TV up?

Thanks,
Rob

have you looked into getting a mount that slides from left to right?

1. How do I know how thick the boards need to be to hold the screws so the screws don't just rip through under the weight? Can I use 1x4s (3/4" thick) or do I need 2x4s?

2. Is there a particular size screw that I need to use to attach the boards to the studs?

3. Is the stud/drywall/board sandwich going to crush the drywall with the TV up?

1. the price difference is tiny, use 2x4's. Not because it would not work with 1x4, but
nobody will question, no insurance questions, and no future worries with a 2x4. No point.

2. 1/4 or 3/8 lag screws should be fine.

3. Nope. Typical mounts have a large flat surface against the drywall and
it will not crush. Before the drywall would crush, you'll probably torque off
the lag screw heads. (I did that twice.)

Just to round out the thread:

I must have checked this thread right before you posted, because I had given up on getting responses, and did the mounting with two 1x4s. The TV floats pretty far out from the wall even with the 1x4s, so I really didn't want to add an extra inch if I didn't have to.

Each board is held in by four 5/16" lag screws, plus one in the center stud. I used 5 shorter lag bolts to mount the plate onto the boards, plus the two lag bolts that are going into the center stud. Hopefuly the overkill on lag bolts will distribute the load and make the thinner board a non-issue.

I hung my 170 lbs on the extended mount for a few seconds and it seemed rock solid, so I think I'm good!