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I have a 75" TV that I want to mount above a wood burning fireplace (don't worry, the fireplace is not in use!) in a 1920s built house. I have bought this pulldown mount from Monoprice (https://www.monoprice.com/product?p_id=27773). The weight of the TV is 79lbs and the mount itself is about 33lbs.

The wall is plaster and wood lath with brick behind. The brick is about 2.5in behind the face of the wall (plaster and lath about 1.75in and 0.75in gap).

Since the wall bracket for the mount is I-shaped (i.e. bolted across the top and bottom, I'm thinking to cut out two parallel channels in the plaster the width of the mount to expose the brick, fasten 2x3 lumber using anchors into the brick so it is flush with the wall, then attach the mount to the 2x3 using lag bolts as if they are studs.

Requesting feedback or other suggestions. Hoping to limit intrusion into the plaster or face my wife's wrath. Thanks

EDIT: Slight setback during the installation...the adhesive started gelling in the nozzle in less than a minute and my caulk gun broke. I managed to get some in all the holes (don't think the last hole was fully filled) along the top row and get the rods in place. Hopefully it's enough. Need to go buy a new gun to finish the bottom!

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    It sounds like a well thought out plan. You certainly want to avoid mounting to plaster and lath! If you have the ability/inclination to patch/paint the wall, you might want to cut a third channel for cables and AC power. (Put a wiring conduit in that channel and cover it up)
    – Steve Wellens
    Commented Jun 22, 2020 at 4:30

3 Answers 3

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Feedback: sounds like a good idea. But I suggest you use as big fasteners as possible, as your moment on them will be quite high...the load being so far from the anchors themselves. Something at least 3/8" or even 1/2".

The entire weight of the set is around 112lb and your TV will stand at least 6in from the brick surface; this will create a torque of ~56 lbf, higher the more you extend the arm away from the wall.

I suggest you consider fastening the TV-mount THROUGH the wood, into the brick itself, and consider the wood just a "spacer", as 2" of wood only may be to little to hold the assembly. I would personally install a long internally-threaded sleeve (such as this), and fasten it with a chemical anchor such as Hilti HY-270, Simpson Strong-Tie AT-XP, DeWalt AC100+ or other similar non-epoxy resins suitable for masonry. You can then drill and drive threaded rods through the lumber, and fasten the mount with nuts. If you cut the threaded rod to the correct length, you can use black dome nuts, that would look as good as a regular bolt.

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  • Thanks to both Jasen and FrK for your suggestions. It sounds like you both think it would be better to fasten the mount directly to the brick using long threaded rods. The difference is that FrK recommends using a chemical anchor vs Jasen using expanding sleeves. Assuming equally effective, is the benefit of the chemical way that there is no expanding stress that could crack the brick? (sorry, have never done either)
    – Matt
    Commented Jun 22, 2020 at 13:09
  • @Matt I agree, both are good suggestions, I like this answer a bit better with the wood as a spacer. One drawback to the expanding anchors is they could potentially crush the brick instead of expanding and squeezing into them. A lot depends on the type of brick used in your house (the age has nothing inherent in it, though the brick could have some damage due to age). Older brick does tend to be softer than more modern brick, but it's no guarantee.
    – FreeMan
    Commented Jun 22, 2020 at 13:26
  • One limitation: the holes in the mount seem to only be big enough for a 5/16 rod. I found this adhesive stocked at my local store Hilti HIT-1 (homedepot.com/p/…). Think I could get away with this? I want to avoid cost of a special dispenser that I would only use once. Lastly, I can't seem to find a threaded sleeve on my store's site. Possible to resin the rod directly in the hole? Sorry for such basic questions.
    – Matt
    Commented Jun 22, 2020 at 15:50
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    @Jasen: epoxy works by "glueing" to the clean surface. It needs a VERY clean surface. You can't ever clean solid brick very well...it releases powder all the time. You will notice that no manufacturer in the world offers an epoxy chemical anchor for brick; instead they have the so-called hybrids (which are a mixture of inorganic elements such as sand and cement) with an organic resin (usually an acrylic resin, similar to plexi). Hilti's products in this line are the HY lines, Simpson has the AT line, DeWalt's are the AC lines.
    – FrK
    Commented Jun 23, 2020 at 14:26
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    Really knowledgeable comments from all - can't find this information on any technical sheet or manual. I am going to try using a resin, 3/8 threaded rod (will need to file the holes in the mount slightly larger), 1/2 drill bit, embed in the brick to at least 3.5". Once mounted, I will test thoroughly using weights before putting the big tv on it and let you know how it turns out.
    – Matt
    Commented Jun 23, 2020 at 14:55
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I'd go with expanding sleeve anchors into the the brick and threaded rod out of the wall, set a nut just below the plaster level, then a washer then your TV bracket then another washer and nut

M8 threaded rod should be plenty stuff enough to hold your TV bracket, so go with sleeve anchors in that size.

the hole in the brick will be about 10mm but you'll need to carve a recess in the plaster to hide the back nut for fastening the bracket, and if your sleeve anchor has a flange you'll need a hole through the plaster large enough to pass that.

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3
  • Thanks to both Jasen and FrK for your suggestions. It sounds like you both think it would be better to fasten the mount directly to the brick using long threaded rods. The difference is that FrK recommends using a chemical anchor vs Jasen using expanding sleeves. Assuming equally effective, is the benefit of the chemical way that there is no expanding stress that could crack the brick? (sorry, have never done either)
    – Matt
    Commented Jun 22, 2020 at 13:09
  • There's a potential issue with expanding anchors in brick. If the brick is soft, the anchor could simply crush the brick out of its way instead of tightening in and gripping. Other than that cautionary note, I think this is a fine answer.
    – FreeMan
    Commented Jun 22, 2020 at 13:27
  • It's almost guaranteed: insert a high performance wedge bolt, and it will destroy the brick. You have a lot of other choices, i.e. low-expansion anchors (e.g. a sleeve anchor), but they are mediocre solutions: you could try a RedHead, Hilti or Simpson sleeve anchor, all available at Home Depot. But they need at least 1" embedment in brick, and can give you only 340lb allowable load, and require a minimum spacing of 2 full bricks in any direction.
    – FrK
    Commented Jun 23, 2020 at 14:21
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I agree with the earlier commenters that suggest drilling a clean hole thru the outer layers and into the brick. I am concerned about the use of “glue”. Anything “air dry” is not going to get any circulation. This is a job for a 2-part masonry epoxy.

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