Mounting TV above fireplace. Plaster with metal behind?

I'd like to mount our 55 pound television above our fireplace (yes, I know all the pros and cons). The wall is plaster and although I was hoping to find a stud, it looks like the brick of the fireplace extends only up to the height of the mantle and from there up, there is apparently solid metal behind the plaster.

I took a picture and labeled where the metal is. It looks quite thick (at least 1 inch all around).



I've been reading about mounting TVs above fireplaces and haven't seen this before so I'm wondering what my options are.

I thought perhaps wall anchors (Toggler brand SnapToggles) but don't believe their is any gap between the plaster above the mantle and the metal behind it.

Anyone have any ideas?

Thanks

 

The wall can't be just plaster. It's a firebox/chimney. There would have to be at least bricks between where you shot your picture to the face of the plaster wall.

You can use plastic anchors or I'd use lead anchors into the brick. You need to be aware that you don't want to penetrate into the firebox/chimney area.

You need to tread carefully here.

 

Thanks but how can I confirm that there is brick between the firebox and the plaster? I drilled a hole and after an inch of plaster it appears that I've hit metal (the brown in the hole matches the brown metal inside). Also, when I put a stud finder above the mantle, it sticks to the entire area above the mantle. If there was brick behind there, would the stud finder do that?

Assuming that there is brick (or not), how exactly do I go about insuring that I don't penetrate into the firebox. Is there a specific depth (say 1/2 inch) that I can safely drill? How much depth is needed for anchors.

Lastly, as mentioned, the plaster is an inch thick. Is that strong enough to hold some type of anchor and the weight of the TV on its own without drilling further in? Like I said, there is no gap behind.

Thanks again.

 

If it relevant, this house was built in 1940..

 

I'm not a pro on fireplace construction so I'm out of my element here. It would appear that you have some type of metal chimney.

No... an inch of plaster would not be enough to support the weight of that TV. It would stand to reason that there must be studs in that wall as plaster is held to the wall with mason's lath and mason's lath needs to be attached to studs.

There are others that may have a better idea on that construction and will offer their opinion.

 

Not sure what mason's lathe is but there is no wood lathe behind this. Perhaps it's sheetrock and not plaster. Not sure but rest of house is definitely plaster walls.

 

Plaster would be very hard. You would have to hammer a nail thru plaster while you could just push a nail thru sheetrock.

 

Where is your pix taken from? What are the steel plates? Your flue? Can you see up the chimney to tell if you have a terra cotta flue, or if it has been updated somewhat with metal? Plaster, no matter how thick it is, will not hold weight. What plans have you made for supplying power and cable/HDMI to the location? That alone will require penetration into the chase, so we really need to know its construction. Pictures from all around will help.

 

The picture is taken from the position of me lying on my back on the fireplace floor photographing up. The right side of picture is the brick of the hearth leading up to top of mantle. A few feet up on left, you can see where the metal starts. Here are a few more pix lying on my back




The square area is what appears to be metal all around. And like I said, the stud detector magnet sticks to the entire wall above the mantle.

I don't know if it's a terra-cotta flue but here is a picture of the chimney from outside:



and the fireplace from the inside:



As for the wires, the previous owner (we recently moved in) installed an electrical outlet right into the top of the mantle. We actually have the TV sitting on the mantle now but because the AC outlet is right in the middle, we can't center the TV and plug it in at the same time. I guess my other alternative is to move the AC outlet but I know less about moving outlets than I do about chimneys. That said, I find it strange that there's an AC outlet in the mantle in the first place given the possibility of heat. Here's a photo of that.

 

You say a magnet sticks to the plaster wall all over it? If so, it may surely be a lath backing. I would make a core cut, approximately a 1 1/2" hole saw, very carefully, one layer at a time, inspecting the next layer before drilling. It should reveal plaster, lath, possibly tar paper, then brick or lumber backing. If you get to a terracotta layer, back out and patch the hole, as it will not be possible. If you get to brick, you may stand a chance of attaching expanding fasteners in the brick to hold your TV.

 

Thanks very much. As I haven't done this before, should I just buy something like this:



and that will simply connect to my cordless drill?

Time for me to now also google patching plaster!

Again, thanks very much for the responses. Much appreciated.

 

That would work. Be careful as Pete said and go slowly with each layer. You will probably feel as you go through each one.

 

Cordless drill would be third choice. 3/8" cored drill second choice. 1/2" corded drill first choice. I would not recommend impact mode in plaster even though the hole saw is rated for that.

 

Is the firebox steel or firebrick? If steel then maybe you have a heatalator type fireplace. The positive test with the magnet could be because there is metal lath behind the plaster. But ere has to be something somewhere to support the lath and plaster. I suppose there could be woven wire lath but I am thinking diamond mesh or rib lath. It looks like the top of the chimney needs some pointing. I have seen masonry chimneys built roughly flush with the wall studs then later installed over the brick and plaster applied Xcode continuously over the wall. If this is done there is usually something to break the bond of the plaster to the masonry.

The advice to be cautious is important
Now high is the ceiling? Is thee some kind of a ceiling mount that can get the TV down to where you want it?

 

I like Tightcoats suggestion. Swag chains from the ceiling would be one idea. Maybe black to match the TV or brass as an accent or painted to blend in..

 

So I've finally had a chance to do some drilling with the hole saw. As it turns out, it looks like there is steel mesh mixed in with the plaster. Here are the photos:

These are the holes I drilled (wife won't be pleased!)


First hole - I believe this may be terra cotta but not sure.



This one looks like I've found some lath.



I can't even drill through this one so quite strong.



I've read that plaster with metal mesh is quite strong so between the thickness of the plaster/mesh and then perhaps hitting a piece of wood lath, I'm wondering if that would be strong enough to hold the TV (55 lbs). Otherwise, should I keep drilling looking for a stud? I found one on other side of fireplace (in the dining room) and figured there would be on at same place on fireplace side (center hole) but no such luck.

Any thoughts?

Thanks.

 

I don't know about terra cotta but it sure looks like a flue liner.

The lath is running vertically which means there must be horizontal studs that they are fastened to.

 

If the pictures are oriented correctly and if the lath is oriented correctly then the lath is installed horizontally which is correct. In the middle of the three closeups of the holes the wood looks like OSB. Could it be that the fireplace was added? If so then this is what I guess. There is a steel firebox and steel flue. It is not as wide as the wall. There is wood framing on either side of the flue and it is sheated with something. It could be OSB or plywood or dimension lumber. You might have found the transition between flue and framed wall. You might have found a stud. You can do some more drilling with a small masonry bit in line with the exposed wood and see if you hit wood or something harder above and or below your saw holes. If you drill with a masonry bit and drill slowly you can tell when you hit wood. If the wood is a stud or even OSB or other sheating they you can screw to that if it works out space wise.
The last hole that you could not get through could be just because you have worn out your hole saw.
If this were mine and I was set on mounting the TV to that wall I would cut a strip of plaster out across the area where I wanted to mount it and see exactly what I had. Of course I know how to fix the cut.
Maybe what you have is framing beside the flue then metal lath bridging the space over the tile or steel flue.
Or you can get a good hot fire going and feel where the wall gets hot. That might tell you something.
Or look into a suspended ceiling mount.
What is the firebox? Is it fire brick or steel?
I think the fact that someone put an outlet in the top of the mantel might indicate that that was the only alternative. That may or may not be because they could not get to the area behind the plaster.

Let us know what you find. You are also going to need to know how to patch your holes. It's simple and you have a couple options. Tell the wife not to panic other than for the mess of the sawing dust.

 

Thank you both for your reponses. A few questions:

Tightcoat, I'm confused why the second hole picture shows that the lath is applied horizontally. If it was installed horizontally, wouldn't it be nailed to a stud on either end? That is, if the second photo is the left side of a horizontal piece, wouldn't the stud show in the photo? Or would the lath end extend past the stud and, in that case, I would expect to find the vertical stud somewhere to the right of the hole?

In answer to your question, I don't know if the fireplace was added. But if I understand what you're saying about the firebox frame, you're saying there should be vertical studs (horizontal as well?) a bit wider than the flue but with plaster and lath (and metal mesh) on top of it. And in that case, I could either find the studs and mount the TV or find the studs and put a piece of plywood horizontally across the mount the TV. Is that right?

I don't know what you mean about "fixing the cut" and also not sure what you mean when you say I might have already found the stud. Where would that be in the posted photos? Behind the lath end in the second photo?

Also, is it possible that the 2nd hole photo does show the left side of a piece of vertically installed lath as PJMax says?

Sorry for all the questions. I'm just wary about drilling too far in or in the wrong place.

And yes, I would welcome some advice on patching the plaster!

Thanks again

 

In each of the pictures the long dimension of the lath runs left to right. If this is correct then the lath is horizontal. Good construction would mean that the studs are up and down.
maybe I better back up. The black mesh is the lath. It is metal lath. That is why I think it is installed across the studs and that one picture shows the edge of a stud.
Metal lath is 97" X 27-28" The lath is installed across the supports perpendicular to the supports. Your lath is horizontal therefore the studs must be vertical

Metal lath with gypsum plaster is superior quality construction or else it was used for a specific reason like bridging the flue. Incidentally, its a little hard to tell for sure from the picture but I think the lath was installed backward.

I can't both post and look at the pictures at the same time. Or at least I don't know how so maybe more later after another look.
I had not thought about putting plywood across the studs if they are not located to suit you. Yes, you can do that. Make sure you use long enough screws through the plywood, through the plaster into the stud far enough to hole the weight of the TV, the mount and the plywood.

WRT repairing the cut: If I cut a slot across the wall to see what I had I could fix the slot cut.

Probably the easiest way to fix the holes is to use the same saw to cut some drywall to fit the holes and use liquid nails to hold it in place. It should be shy of the finished surface so fill the hole with joint compound. Were I to do it this way I would use some setting compound. But I would not do it this way. I am just telling you what I think is the most amateur friendly way to do it.

I am referring back and forth to your last post. I think what PKMax and you think is a vertical lath is a stud or else OSB.

I'll look at the pix again and maybe think of something else.

 

I see what you're saying be what makes me think the wood in picture is lath and not a stud is that it's only about a half inch thick. I'm judging by the drilled hole in it. By the way, I don't know what that is behind it. I tapped a small nail in and it went in but was nervous about driving the nail in too far in case it wasn't a stud (or even wood). I couldn't really tell.

 

In picture 3.... you say the wood is roughly 1/2". I thought it was the end of a piece of wood lath but now that I look again.... it appears to be plywood. I can see the plies thru the drilled hole. Lath would be solid wood.

 

What is the spacing between the holes you have? Do I see wood on the right side of number three and on the left side of number four. Do a little more exploration and figure out how thick the wood is and how wide and try to trace them up and down and also how they are spaced.

 

Ok, I've drillled a few more holes.

If you look at the first picture above with the three holes in a horizontal line, this picture shows some more holes I drilled around the middle hole.



There is no wood in the big hole on bottom left



and no wood in small hole to right of center big hole. So it appears that the wood is not laid horizontal but rather vertical.

Looking back at original three horizontal holes, here is a another shot of the one on the right.



Again, this also appears to be a vertical piece of wood with a big piece of metal to the right of the edge.

Given how deep the plaster is (about an inch thick and very solid), I was thinking of trying to mount into the center vertical wood strip but just not sure it's strong enough. Also, the screw is about 2 1/2 inches long and I think I only have about 1 1/2 inch before I hit what ever is behind the wood. I guess I could find 1 1/2 inch screws but again, not sure if that's a smart move.

I'm also thinking that since I know I have two vertical strips, perhaps there is a horizontal stud at the top or bottom. However, other than continuing to randomly drill, I don't know how to find it. And if there is one, it might end up being up near ceiling which won't do me much good.

Any other thoughts? Ultimately, I'd love to still find a centrally located stud but am a bit lost at moment.

Thanks.