Want to mount TV over fireplace but stud finder showing large metal area

July 6, 2014 10:34 AM

I have a home built in 1940 with (I believe) plaster walls. The chimney runs down enter of house. We'd like to mount TV above fireplace but my stud finder is essentially showing the entire space above the fireplace to be metal (finder sticks to wall over entire area).

If I run the stud finder over wall on back of fireplace (which extends into dining area), the metal is not there so looks like it's front of fireplace only.

I believe I may be able to find studs by measuring 16 or 24 inches from doorways (or finding studs on opposite side, which I assume should line up with front?) but what is that metal and would I damage my fireplace if I was to pierce it? Perhaps it's some type of shield or liner?

posted by gfrobe to Home & Garden (8 answers total)

It's likely an expanded metal plaster mesh/lath that your stud finder is detecting. You might not have any studs where the mesh is located as the builder may have plastered directly over the bricks (if you have a brick fireplace).

It's going to be tough for anyone to tell if it is dafe to drill into your particular chimney with out seeing it. Can you post any pictures?
posted by Mitheral at 12:46 PM on July 6, 2014 [2 favorites]

Response by poster: Thanks for the reply. Wasn't sure if you wanted pictures of chimney or fireplace so have included both. Here is the link to photos.

I'm guessing my best bet might be to cut a small hole where I think the stud might be to have a look, and if the stud is there, it doesn't look look like the mesh should be a problem to work around. Does that sound right?
posted by gfrobe at 3:29 PM on July 6, 2014

I'd double check and see just how insulated the flue is behind the wall. You're obviously planning to run power lines and various cabling inside that wall. If it's just a bare brick flue in there, it could get pretty hot. Perhaps hot enough to melt cables.
posted by Thorzdad at 4:26 PM on July 6, 2014

Response by poster: Thanks Thorzdad. There is an AC outlet already built into the top of the mantlepiece so I could probably get away with not running any wires in wall.
posted by gfrobe at 4:55 PM on July 6, 2014

Also, most stud finders are reliably, repeatably shit.

I returned one once to the store, and when she asked if there was anything wrong it it, I passed it over her empty plastic trashcan. It found studs. Same place every time.
posted by IAmBroom at 7:24 PM on July 6, 2014 [1 favorite]

Apart from difficulty in installing a mount, there are some other reasons why you should consider not mounting a TV over a fireplace:
1. Heat and smoke and soot from the fire do not mix well with the electronics in the TV and will shorten their life.
2. The TV is probably going to be too high for optimum viewing - and it may not be well placed for off-axis horizontal viewing (especially if it is an LCD)
3. You are more limited in terms of safe and concealed means of running cables.
- It may still be your best option, especially if you don't use the fire, but these are worth mentioning before you drill.
posted by rongorongo at 11:13 PM on July 6, 2014

Why not build up an impressive fireplace mantel and place the tv in the new woodwork? Use the newly built up area to conceal cable runs. There are some interesting ways to mount the tv and allow it to pull away from the fireplace and/or change the viewing angle.

I also second rongorongo on the heat/smoke/soot, view angle/height comments.
posted by Leenie at 1:34 AM on July 7, 2014 [1 favorite]

Best answer: gfrobe: "I'm guessing my best bet might be to cut a small hole where I think the stud might be to have a look, and if the stud is there, it doesn't look look like the mesh should be a problem to work around. Does that sound right?"

If it was me I'd just drill a small careful hole right where I want one of the mount screws. One of three things will happen:

1. You drill through up to an inch of plaster and foundation materials and then hit brick. In which case drill the brick for a lead anchor (Lag Screw Expansion Shield) (usually cast in zinc now not lead) to hold your screw
2. You drill through up to an inch of plaster and foundation materials and then hit several inches of open space (maybe with fiberglass insulation). In which case enlarge the hole to hold a butterfly anchor and use those to mount your TV.
3. You drill through up to an inch of plaster and foundation materials and then hit wood. Yay! you found a stud. Use an appropriate wood screw to mount your TV.

This way you end up putting your TV where you want it not wherever your studding works out. A TV over a fireplace not centred on the fireplace is going to look weird.
posted by Mitheral at 6:36 PM on July 7, 2014 [1 favorite]