# Anyone ever hung an LCD TV on a plaster/lathe wall?



## fabrk8r (Feb 12, 2010)

You can do it yourself by using *lag screws* to attach the mounting brackets through the plaster and lathe and into the wall studs.

I have never had luck using a stud finder to find studs through plaster and lathe due to the thickness of the plaster plus the 1/4" wood lathe. I find the location of the studs by first measuring from a known stud location. This will get you close. Then drill a small hole through the plaster and lathe and insert a coat hanger which is bent so it will detect the location of the stud. Pull the wire out and use it as a guide on the wall to mark the center of the stud (add 3/4").

You may have to drill the holes in the mounting brackets to a larger size to accommodate the lag screws. I usually use at least 5/16" X 3" lags, but for heavy items like TV mounts I use at least 3/8" X 3-1/2" lags.


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## jpearson311 (Dec 29, 2009)

fabrk8r said:


> You can do it yourself by using *lag screws* to attach the mounting brackets through the plaster and lathe and into the wall studs.
> 
> I have never had luck using a stud finder to find studs through plaster and lathe due to the thickness of the plaster plus the 1/4" wood lathe. I find the location of the studs by first measuring from a known stud location. This will get you close. Then drill a small hole through the plaster and lathe and insert a coat hanger which is bent so it will detect the location of the stud. Pull the wire out and use it as a guide on the wall to mark the center of the stud (add 3/4").
> 
> You may have to drill the holes in the mounting brackets to a larger size to accommodate the lag screws. I usually use at least 5/16" X 3" lags, but for heavy items like TV mounts I use at least 3/8" X 3-1/2" lags.


Thanks for this. What about the component and electrical wires for the tv? I don't want them just running down my wall.

Jesse


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## fabrk8r (Feb 12, 2010)

jpearson311 said:


> What about the component and electrical wires for the tv? I don't want them just running down my wall.
> 
> Jesse


The easy solution is a cord cover. They are not the most attractive option, but it's easy and quick. They are available is numerous sizes and colors and can also be painted to match the wall. They have an adhesive on the back and a snap on cover.

A more eye pleasing alternative would be to cut an opening in the wall behind the TV and install a couple of 2" X 3" boxes, one of which contains the coax and component connections and another for a duplex receptacle for power. This would involve snaking wires and cables through the wall cavity and is fairly easy if there is a basement or crawlspace directly below the space where you are placing the receptacles. The only problem with this scenario is that you won't be able to staple the romex to the stud without tearing out some of the wall and patching it.:wink:


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## jpearson311 (Dec 29, 2009)

fabrk8r said:


> The easy solution is a cord cover. They are not the most attractive option, but it's easy and quick. They are available is numerous sizes and colors and can also be painted to match the wall. They have an adhesive on the back and a snap on cover.
> 
> A more eye pleasing alternative would be to cut an opening in the wall behind the TV and install a couple of 2" X 3" boxes, one of which contains the coax and component connections and another for a duplex receptacle for power. This would involve snaking wires and cables through the wall cavity and is fairly easy if there is a basement or crawlspace directly below the space where you are placing the receptacles. The only problem with this scenario is that you won't be able to staple the romex to the stud without tearing out some of the wall and patching it.:wink:


Ok, let's say I want to mount my TV on the wall and right underneath my tv is where all my peripherals will be (i.e., cable box, DVD player, stereo receiver, etc). If I have 2"x3" boxes in the wall behind the tv for component and power cables, wouldn't I have to have another component cable box down near the floor so my dvd, receiver, etc. can connect? The 2 boxes would of course be connected to each other inside the wall. See what I'm saying?

Jesse


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## Yoyizit (Jul 11, 2008)

jpearson311 said:


> Is this possible? Best Buy told me they wouldn't hang my TV on a plaster wall. How can I do it myself? Thanks!
> 
> Jesse


How much does it weigh? A 42" weighs about 70#.
Flat against the wall or at the end of one of these articulated arm things?
Pullout force for hollow wall anchors in plaster is pretty high.


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## jpearson311 (Dec 29, 2009)

Yoyizit said:


> How much does it weigh? A 42" weighs about 70#.
> Flat against the wall or at the end of one of these articulated arm things?
> Pullout force for hollow wall anchors in plaster is pretty high.


My TV weighs about 34 lbs. and I want it flat against the wall.

Jesse


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## Yoyizit (Jul 11, 2008)

Of course, now I can't find my table of pullout strengths for various fasteners and wall materials.

Here is one link
http://www.oldhouseweb.com/how-to-advice/hanging-objects-from-plaster-walls.shtml

For four fasteners, all will have a shearing force on them but only the top two will also have some pullout force on them. 

34#/2 = 17#. 
For a safety factor of 4, the top two fasteners need a min. pullout strength when used in plaster of 4(17) = 68#.


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## stadry (Jun 20, 2009)

70# weight


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## stadry (Jun 20, 2009)

70# + weight of the mount would be fine for shear AND pullout BUT if you've got this many questions, probably best to find a decent carpenter rather'n watch your very fine tv seek the floor due to improper work,,, you're your own best critic far's ability.

pullout strength of ANY anchor in lath/plaster wouldn't be acceptable to me NOR would i even think of attempting it in ANYTHNG but studs !


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## Yoyizit (Jul 11, 2008)

The other option is to make a wooden plate at least 18" lg and screw it onto the studs [if you can find them through the plaster] then put the mount on the plate where you want it. 
But it probably won't be centered.

For the two years I worked as a h/w store clerk almost no one had studs where they wanted them. 

We used Hillman hardware and they had tutorials on their website where they talked about low density materials and high density materials, etc., and the fasteners to be used with them, so I made up a bunch of gypnotes about fastening to plaster, drywall & cinder block.
And some fastener packages show ultimate strengths for the different materials they might be used in. You have to scrounge around. 
The fastener manuf. for sure can advise on this. 

Servalite and Midwest may have fastener tutorials somewhere on their websites.

I found my fastener tutorial file on my back-up computer but it doesn't view correctly. Probably I have to open it in WP51, if I still have that program. It might be saved on a disk somewhere as a text file.
Computers are great when they actually work.

And, test your work. 
Fasten the mount and load it to 4x the expected load. 
Better it falls on the floor then and not later.

BTW, those gypnotes came in handy when a very serious, blue-eyed young honey questioned me for a half hour on fastener strength. I've never been interrogated like that in my life.
She didn't seem all that impressed, but the next night she was back asking for me. I was off, so somebody else had to deal with this lady. I bet she turned him every way but loose.


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## gregzoll (Dec 25, 2006)

Only if you can attach to studs or a ledger board behind the lathe. If you want to wake up to a crashing LCD, go ahead and just attach to the Plaster & Lathe.


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## Yoyizit (Jul 11, 2008)

gregzoll said:


> If you want to wake up to a crashing LCD, go ahead and just attach to the Plaster & Lathe.


http://www.google.com/search?hl=en&...f+little+faith"&aq=f&aqi=g2&aql=&oq=&gs_rfai=
:laughing:


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## rjniles (Feb 5, 2007)

This is what I did for a buddy to hang is 52" flat screen. This was on drywall but no reason it will not work with plaster / lath. I cut a sheet of 3/4" Birch plywood a couple inches smaller than the TV. Cut 2 opening for electric boxes in the plywood (one for a receptacle and one for the low voltage stuff-used a LV box with a open back). Opened a hole in the wall about 2 feet wide and 1 foot high. Fished a 12-2 cable inside the wall to a receptacle below the TV (lucky here). Installed another LV box down low. Mounted the plywood to the wall with a lot of heavy screws, caught 2 studs. Trimmed out the plywood with 1/4 round molding and painted with a white semi-gloss. I would have used the wall color but he didn't have any. Hung the TV mount with lags into the plywood, installed the receptacle, fished the low voltage wires between the 2 open back boxes. (The open back LV boxes allow any new wiring to be easily installed.) Hung the TV on the mount, one of those ones that pulls out like a scissors jack and tilts side to side.


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## Yoyizit (Jul 11, 2008)

rjniles said:


> that pulls out like a scissors jack and tilts side to side.


That kind puts enormous stress on the wall fasteners on the top of the mount. 

That's why the mount is so chunky. It has to resist being torqued off the wall.

You might want to test it with the mount fully extended [worst case].

You have a link to the mount dimensions? This is what I was going to install in Reston, VA on a panelled wall but Panasonic wanted $200 for the mount so the HO opted out. Now they're going to put it on a table.


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## rjniles (Feb 5, 2007)

Yoyizit said:


> That kind puts enormous stress on the wall fasteners on the top of the mount.
> 
> That's why the mount is so chunky. It has to resist being torqued off the wall.
> 
> ...


Here is the one I used from eBay:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=230458928034&ssPageName=STRK:MEWAX:IT

The shipping cost is crazy but the total price at a little over $90 is great.

I hung my full weight (165) on it, with it fully extended. It is solid!


Here is the same one for $20 less:

http://cgi.ebay.com/LCD-PLASMA-FLAT...tem&pt=LH_DefaultDomain_0&hash=item35a9127506


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## cellophane (Sep 29, 2009)

fabrk8r said:


> I have never had luck using a stud finder to find studs through plaster and lathe due to the thickness of the plaster plus the 1/4" wood lathe. I find the location of the studs by first measuring from a known stud location.


Stud finders usually do work with plaster but you have to shell out for a good stud finder. The $10 wal-mart variety won't do the trick.


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## Yoyizit (Jul 11, 2008)

rjniles said:


> I hung my full weight (165) on it, with it fully extended.


That's what I would have done.

I'm thinking the set weighs 78# so you've tested it to a safety factor of 165/78 = ~2. If you dare, test it to 4 by putting 330# on it. You might expect wall bulging or hairline cracks at this weight, but if it holds, it passes. Have an assistant hold a straightedge on the wall as an early warning.

For personal safety, safety factors of at least 10 are spec'd.

As more people torque the middle of studs in this way, I'd think the building codes would be recommending beefing up studs to resist this stress.

Thanks for the links; I'll tell the Reston HO that she can have a mount for a lot less than $200. She doesn't have Internet access; she should, for shopping and to stay 'connected' [she can't walk that well].


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## fabrk8r (Feb 12, 2010)

jpearson311 said:


> Ok, let's say I want to mount my TV on the wall and right underneath my tv is where all my peripherals will be (i.e., cable box, DVD player, stereo receiver, etc). If I have 2"x3" boxes in the wall behind the tv for component and power cables, wouldn't I have to have another component cable box down near the floor so my dvd, receiver, etc. can connect? The 2 boxes would of course be connected to each other inside the wall. See what I'm saying?
> 
> Jesse



Yes, you are correct that you would have to have wall plates in both locations. 

You have numerous options. Some people just punch a hole in the wall and feed the cables through with a wire snake. Not the prettiest way to do it, but the components and monitor hide the holes.

You can buy special cover plates that allow you to feed the cables through and still connect directly to components and have it look somewhat finished.









One more option is to use dedicated component wall plates that are connected to each other behind the wall and you just plug your component in. Place one behind the monitor and another behind the video/audio components.









You could even go so far as to install audio connectors in the walls and run speaker wire in wall cavities to supply connection points close to speakers.

I should also say that my home, which was built in 1908, has plaster and lathe walls and I have installed several wall mounted TVs (some heavy CRTs and some flat panels) using the method I talked about in my first reply. I have had no issues with cracking plaster or breaking studs.


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