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My son has just fitted my new 40" LED TV to drywall.

He did attach a board to the drywall but when he purchased the board he had assumed the metal studs were 18" apart not 24" so only bought a 20" board which wasn't wide enough to span two metal studs.

He fixed one side of the board to a metal stud (not sure which fixings he used in the metal stud but he didn't use the snap toggles I supplied) he then used two snap toggles to fix the other side of the board to drywall.

My TV bracket is a cantilever and only has about a 6" square wall plate which he fixed to the centre of the board (not sure if he used Snap Toggles).

I know Snap Toggles are supposed to be good but my concern is that if only two were used as described will this be enough to support the TV?

The TV seems to be held up really firm and the cantilever action works well but I'm just feeling nervous so I decided to research the fixing of TV's to drywall (I almost wish I hadn't!).

Can you please advise if I could be in trouble? If necessary I could not use the cantilever action as I only want to angle the TV very occasionally. I'm just dreading being told I need to get in a professional TV installer and have everything replaced. I can't bear to think of the mess it would make of the walls let alone upsetting my son after all his hard work. No mum likes to upset her son and it would be especially hard considering he is a carpenter.

isherwood
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Sheila Goswell
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I must say that the "carpenter" son seems to be a bit of a non-professional if the description you gave of the installation is correct. Mounting a cantilever arm as described seems to me like it asking for trouble. Even with a smaller sized TV the cantilever arm, when extended, will put a rather large pull out force on the fasteners in the drywall.

To avoid any unfortunate mishap I really suggest getting that short piece of board removed. It should be replaced with a sturdy piece of 0.75 inch thick plywood that spans at least two studs and has a height of at least two feet so that fasteners into the studs can be spaced a good distance apart near the top and bottom of the plywood. Then remount the cantilever arm plate to the plywood. That should give a very reasonable and secure mount for the TV.

The plywood piece can be sanded and painted up nice before attaching it to the wall. If the color matches to the wall it would blend in well and not appear to be out of place behind the TV.

Michael Karas
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  • Thank Michael. I tend to agree with you, I think my son was managing with what was available at the time. I may be doing him and injustice and he may have used the correct screws in the metal stud but even if they are I'm still concerned with it only being held by the one stud. He was disappointed the board he had wasn't big enough to span two studs but I had already waited three months for him to do the job and I don't think he dared say he couldn't do it. I also don't think he has the knowledge of TV Brackets and their force is non existent. I will get a professional in, Many thanks. – Sheila Goswell Sep 28 '15 at 11:41
  • I don't know if I'm putting this in the right place to ask you Michael but if you see this can CAN I PLEASE ASK YOU URGENTLY DOES IT MATTER IF THE BOARD USED IS PLYWOOD OR MDF? Everywhere I read about this as to use Plywood is there a reason for NOT using MDF? – Sheila Goswell Oct 02 '15 at 13:35
  • Again not sure if you will see this Michael so I know I'm posting this information twice and I apologies for this but as you have been so king and knowledgable in answering my last question I'm hoping you can answer the following: – Sheila Goswell Oct 02 '15 at 14:20
  • Sorry to add another question but I have found a wall bracket which spans 24" studs. I know my studs are metal but could I hang this straight it the paywall using the studs with just good snaptoggles or will boarding the wall first with either Plywood or MDF strengthen this further. I can't quite get my head around why a board would add any extra strength. I am concerned that the weight of a Bracket this large may be too much. Is it better to add a lighter smaller base plate on the board or a larger bracket to allow you to spread the load? – Sheila Goswell Oct 02 '15 at 14:27
  • I would always use plywood. It is far superior in holding screws that are under tension. MDF is not much more than saw dust that us ground up with glue added and pressed into a sheet. It will not hold a screw in pull out tension nearly as well as plywood. – Michael Karas Oct 03 '15 at 12:40
  • I would always do as suggested in the answer and use as large of piece of plywood as possible. The plywood spreads the stress across as many mount points into the metal studs as can be added. Then the extension arm bracket can be mounted over the plywood so it's fasteners can be optimized to the bracket as opposed to the stud locations. – Michael Karas Oct 03 '15 at 12:48
  • Do note that metal studs are whimpy as compared to real wood studs and they gain their strength mostly from the fact that they are joined to the wall panels. The plywood that I have suggested over and over extends this idea into the plywood panel too. – Michael Karas Oct 03 '15 at 12:49
  • Hi Michael, I can't thank you enough for all your replies. You have expalined it perfectly. I fully understand what I need to be asking for now. Amazingly, the specialist Company who advertise fitting brackets/aerials (from the first aerials/TV company when I Googled) said what my son had done looked good enough to to him! I was amazed so don't hold much faith in his opinion. He hadn't even heard of plywood being used. I explained all you and I have discussed. He is happy to do this but I can't help but think I should look for someone else. At least I know what I need now. Thanks again – Sheila Goswell Oct 04 '15 at 18:36
  • I hate to bother you again I thought I had this straight!! I read on a similarly thread not to use toggle bolts as the drill hole size needed will wreck the metal studs but I've never come across anyone suggesting not to use toggle bolts before. I was planning on getting my installers to attach the plywood with snaptoggles will this be OK? If not what fixings wouid you advise please? Can he also use snaptoggles through the plywood and drywall to fix the actual bracket to plywood or should he use something else? What width plywood do I need cut to span 2 x 24" metal studs. Gracious thanks. – Sheila Goswell Oct 04 '15 at 19:23
  • Do not use toggle bolts into the metal studs. The large holes required for toggle bolts will not be good for the metal studs. So even though metal studs basically suck you have to interface to them in the correct way. You should be using a properly sized sheet metal type screw that self threads into the sheet metal stud in the precisely sized drilled hole. It is very important to tighten these screws just the right amount. If they are over tightened the threads on the metal stud will strip out and result in a nearly useless fastening. (continued) – Michael Karas Oct 05 '15 at 04:53
  • (continued from above) It would be better to use more of these screws to secure the plywood as opposed to fewer. Note that the plywood idea to re-enforce the wall surface is probably not so widely known because most installers are looking for the simplest methods to get in and out of the job site in the shortest time possible. To achieve that they use methods that are quick and give the appearance of being secure. However, and it is my opinion certainly, the plywood is the best way to go in this instance. – Michael Karas Oct 05 '15 at 08:08
  • Since you have metal studs at 24 inch spacing the minimum spacing of the plywood needs to be 24 inches plus the width of a metal stud. A bit wider would be better. Across three studs would be even better. – Michael Karas Oct 05 '15 at 08:22
  • Hi Michael, you say to use a properly sized sheet metal type screws that self threads, can you advise on a type and size please as I've tried to search and the mind boggles. I am hoping to have the correct tools here ready. Also am I better to buy a larger mount base plate to spread the load across the plyboard or doesn't this matter if fixing to correctly fitted plyboard? One last point, should the mount itself be fixed right through the plywood into the drywall by snaptoggles or fixed in some other way, please advise. I do apologise for bothering you again but you have been so helpful. – Sheila Goswell Oct 05 '15 at 14:06