Hey everyone,

Looking for a bit of advice I was planning on wall mounting my plasma tv 42". I just learned that in my town home the wall I would like to mount on is not studded with 2x4 it looks like it is just small studs aprx 1" by 2" concrete screwed into cinder blocks to mount the drywall to and they are not 16" apart there is only one stud down the center of the room (where I would like to mount the tv) and the next studs are about 30" from there ( much too far apart for a wall mount bracket). My question is how can I still wall mount this tv in the center of the room? I know I can drive a couple tapcons in the middle "stud" but that won't be enough support I would think. Without destroying too much wall how can I get some more support? Mainly on the outer corners of the mount.

cut out the drywall 4" larger then your mount all the way around build up a plywood base the exact thickness from the cinderblock to the *Face* of the drywall (1" I assume since 1x2 is actually 3/4 deep x1 1/2 wide assuming your drywall is 1/2 inch) take some tap cons and fasten the plywood spacer to the wall. Now mark your holes for the mount and then get some hilti toglers and drill your plywood/cinderblock (you will need a hammer drill) Use the togglers to mount your mount :)

you now have a crazy strong support for your TV and have no worries of it falling down. if you find that the cinder block is solid you will have to use red head concrete anchors in place of the toggle's.

Before you throw your TV on the wall take some joint compound and tape and blend in the plywood with the sheet rock, paint to match and you have a seemless transition, later on if you take your TV down just fill the holes from the toggles and paint over.

your next issue is running and hiding the wires, especially power. 3x4 is very tight but you could get a slim HDMI fished through.

So you basically have a 1x2 strapped cinder block wall. That's pretty easy.

First, tapcons don't go into wood, they go into concrete or block.

Second, we hung a 50" last year by just mounting the mount itself straight through the drywall and into the block behind using 1/4" blue tapcons. I might be wrong, but I think we only used 4. The shear rating on even 1 of those is enough to hold a TV. With 4 of them, you're more than golden. Just read your minimum and maximum embedment specs to get the right length.

Next week we're doing a 65" on an articulating arm straight into a poured concrete basement foundation wall - through drywall and about 2" of rigid foam. 3/8 x 5" red head LDT for that, x6.

Tapcons may be small, but they're mighty mighty. :)

yeah but you cant simly mount the mount to drywall with a 3/4 air space behind it, you could never pull it tight and technically your sheer rate is much less because of the torque on the tapcon because the mount is an 1" off the wall.

If this is just a flat mount or tiliting then put the spacer I explained in my first post but then just use longer tap-cons to go threw the spacer into the block, dont worry about using toggles. just make sure the threads of the tapcon stay in the block and dont go past and just into the airspace. if this is an articulating wall mount then its a whole different ball game :)

Maybe we're not talking about the same thing here.

The other word for scissors, which is "shears," gives a clue as to what shear strength really means. Shears cut by applying pressure at right angles to what you're cutting. The paper shears.  Shear strength resists a material parting into two pieces from pressure at right angles to it.

Shear strength is not much of an issue with a TV. Your average 1/4-20 bolt has a working shear strength of about 200 pounds,* meaning that if the bolt goes straight in, you can hang a downward force of 200 pounds and the bolt will not be cut by the forces. Note that working strength means that a margin of strength is built into this; it can probably support a half ton but engineering practices specify it as much less in order to have zero failures.

The strength you mostly need for a TV is pullout strength, and that is only critical on the top. Think about it: if a TV's mounting bolts were loose, the bottom ones would be just fine but the top ones would pull out. The bottom ones wouldn't undergo any force in a direction that would pull on them until the top bolts were out and the bottom of the TV had hit the wall.

Pull-out has two components. One is the tensile strength of the bolt. From the same web page, 1/4-20s have a tensile strength of about 160 pounds. Most of a TV's actual weight pushes down on the bolts, so shear strength, for the most part, holds the mount and TV in place. It takes much less tensile strength to keep a bolt from snapping apart, but the strength shown is 160 pounds....

And that's per bolt. And that's with 1/4-20s. But every TV mount I've ever seen has larger bolts than that, meaning they are all even safer than the description I've given.

This leaves the most important part: the entire mount depends upon what it takes to pull a Tap-Con, or whatever you put the bolt into, out of the wall. Here's where you need to look up the kind of mounting bolt and insert, stop guessing how to use them, and see how they are supposed to be installed.  And if you're using a lead insert, you'll want to be aware that lead is so soft that it moves over time when a force is applies to it.  With a TV mount, that movement will put the TV on the floor.


*[Link: halseymfg.com]

Toggler's work extremely well. I had to use a few of these to hang a wall mount rack in a frozen yogurt store with only a concrete wall behind sheetrock.

[Link: amazon.com]

Thanks for the info guys,

yeah was just worried about putting taps or toggle bolts where there was airspace behind the drywall and no "stud" i guess I will just add a stud of sorts with tap cons, its just a standard tilting mount wont be able to cut out the whole profile of the mount and add wood though as I already have the receptacle and all the AV wiring ran through the wall and it would interfere.

You can if you place the mail bolts right next to the firring strips. The drywall won't compress much unless the bolts are over-tightened and then, more can be added with plastic stand-offs to keep the drywall from bowing and/or collapsing.

Look for these (redhead masonry wall anchors) at your local hardware store and install four of them. Some installers think that these are overkill. I however, walk away from any tv installation 40" to 70", on any mount, knowing that the wall will come down before the TV.

The previous advise on placing them near the furring strips is helpful too.

[Link: walterwood.com]

77w - I just noticed you recommended 5" redheads in your post as well.