Plasterboard wall with no studs inside... ever come across this?

[jaybee]

Was doing some work inside my house and after trying to find studs with a studfinder, magnets and finally tapping nails in to it in intervals...I ended up getting confused as to what I was dealing with. After drilling through a bit the drill jumped and I thought I was at the next bit of plaster but it was too soon....so i drilled a bit more and it jumped again but I thought I was still in the same bit of plaster. I ended up just thinking **** it and promptly drilled all the way through into the next bedroom. lol

To my surprise I found that our internal walls between rooms are what appear to be referred to as laminated plasterboard. They are literally triple layer plasterboard. First layer is about 18mm, then 24mm, then 18mm all stuck together, WITH NO VOID or CAVITY GAP! I assume they are kind of dot and dabbed together as there is a slight tiny gap between each layer where the adhesive must be making up a bit of the gap. By tiny, I mean literally 1-2mm maybe.

Some of them I guess could have timber in...it's hard to tell. On one wall, I put a TV up and thought I was inside a vertical timber stud as it felt solid...but I'm now doubting whether I actually was. I used long wood screws and the TV has not fell down yet.

It brings me to the question of...how do I securely mount a heavy TV if I truly cannot find timber? I saw online that someone found a house like this in the 80s and he said it was basically massive plasterboard sheets nailed to horizontal top and bottom wooden studs which ran literally at the top of the wall by the ceiling, and at the floor behind the skirting, with nothing in between. Someone else said sometimes the middle layer is between the vertical very thin struts, with the outer layers boarded straight over them all the way end to end, so you essentially in some places would have, plasterboard > thin wooden stud > plasterboard all stuck together.

I've had a couple of ideas as to how to mount a TV in this situation:



1: Use the toggle spring plasterboard mounts that spring out behind the plasterboard but since there is no void, basically drill through the first layer with a large ish hole (which the spring toggles require anyway) and then basically somehow carve away the second layer around the hole to leave a void surround the hole big enough to use spring toggles in the normal way. Spring toggles or grip it fixings can easily take a TV weight on plasterboard as I've used them before.
Could be tedious and messy and risk damaging plasterboard.

2: Drill all the way through the wall and use plasterboard spring toggle fixings and cover the other bedrooms toggle fixings with a picture yo. Ghetto. Yeah nah. Probably not wife approved.

3: Just YOLO some great big wood screws or other type of generic screws into the plasterboard going through and into all 3 layers (but not quite through the last one) hoping it will hold. This will be in about 50mm of plasterboard.

4: Same as 3 but with some kind of dedicated super wide big threaded specialist metal wierd plasterboard screw things. I've seen them but not sure if they would work. They leave a threaded section in the middle to wind a bolt into. Will try to find a link.

5: Same as 3 but use a rull plug of some sort which expands inside all three layers. It would be similar to one for use in masonry since there is no void, and would hopefully expand and be strong....but I can just see the plasterboard crumbling as I tighten the screw in.

6: Build out the wall properly extending it with stud framing. Given the room has just been finished and decorated I kind of don't want the upheaval of this. In the other room I have to do this in it's simply not possible either.

Thoughts?

 

[jaybee]

That's a tricky one, as all the decent plasterboard fixing rely on the cavity behind them to grip and spread the load.

Does the TV need to be completely flat against the wall? Will you notice if the TV sits a little proud of the wall? Is this an end wall, or can you easily see down the side/back of the TV? The reason I ask is that my first thought would be to use a combination of these fittings and a decent grab adhesive (left overnight to dry) to secure piece of 18mm MDF or ply to the wall then screw they TV mount onto that with wood screws.
https://www.screwfix.com/p/easyfix-self-drill-plasterboard-fixings-metal-32mm-100-pack/2422H?tc=MB6

It's not ideal, but if you can't easily see the back of the TV then it's the easiest solution I can think of.

Also you can paint the board to match the wall to make it less visible. I would go as big as you can as the larger it is the more surface for the grab adhesive to work on, but obviously keep it smaller than the TV so it's not obvious unless you go looking behind it!

Also, for the record, these aren't my favourite fittings, but they aren't to bad and would work well here.

Dave

Dave that's a good shout. I was thinking of those things just couldn't remember the name. Yeah...I like this idea with the piece of board. This is on a bedroom wall. You can see behind all the TV as you walk in and look to the side...but...as you say, if you paint it wall colour it might be fine. Perhaps I could get away with using 10mm board but long thick screws that go through the board into the plasterboard as well. Only thing with the grab adhesive is I can see when that ever has to come off, it's basically bringing the wall down too lol. Well, atleast the first layer of plasterboard is going to come away with it. But...a) That could be years and years away b) who cares? Buy some plasterboard and make good nearer the time.

What grab adhesive would you recommend? Something like no more nails?

The TV is a 50 inch LED with the usual arse (lower hump) which may make it look a little unsightly having a bigger gap at the upper part especially with the board but still...could be doable.

Do you know if these fixings you linked to come in an even deeper/bigger style, as obviously I've got 18+24+18 depth to play with, so could go up to about 50mm comfortably without going through the wall.

 

[jaybee]

I would probably overdrill and use a resin to fix in place a mechanical fixing if your sure its this construction

Thanks. What do you mean by over drill? I have heard of people using resin for TV hanging but in masonry or solid wall. Do you have a link to the kind of resin product that would suit plasterboard and not be absorbed by it all? Do you mean to set in place threaded rods so I can just wind nuts on the end to secure a TV bracket directly to the plasterboard? This could be an option yes. Hmm. The resin would need to be solid AF.

 

[jaybee]

I have heard about this method,but not seen it in the flesh
Might look a bit ugly but you could put a piece of ply or similar on the other side of the wall and bolt through?and cover with a picture or something if you are really worried about the stress

Yeah I just remembered there are bathroom tiles on the other side :O
Knowing my luck I'll enter a copper pipe to the towel radiator the other side. Joy.
The trouble with this construction is the stud/electrical/metal finder gets confused and can't cope. It can't really be trusted at the best of times, let alone in this setting.

It had a batten on the floor and one on the ceiling and plasterboards were cut snug and slid along with a batten on the wall and at each joint
weird and time consuming i would have thought

Run that one by me again...can't picture what you mean exactly. Can you draw it? I might draw how I think it is

 

[jaybee]

I think it might be constructed like this:


Red shows main ceiling batten from overhead view. Blue shows the outer 18mm plasterboard layers screwed into the ceiling and floor level horizontal battens.

Then the bottom diagram is a side on view looking directly at the wall. This shows the floor batten and ceiling batten and then the possible vertical studs which may exist every time a new sheet starts or possibly there are more. But these would be thin 24mm deep strips of wood.





Then the brown bits are the internal 24mm thick plasterboard sheets cut to size to sit on top of the floor batten and underneath the ceiling one so it is all surrounded by a wood "frame" and sits flush with the battens or just shy of them.





Then the orange plasterboard outer sheet 18mm thick gets dot and dabbed or adhesive stuck onto the inner sheet and screwed/nailed into the top and floor batten and possibly the vertical stud to the right. Then the next sheet purple one, gets the same treatment butted up against the orange one on the vertical strud. Or...the vertical studs may not exist at all.







EDIT: I've drawn the vertical studs badly like they overlap the battens. They wouldn't. They would sit on top of the floor one and underneath the ceiling one and be fixed into place with screws or right angle plate of some sort I would guess.

 

[jaybee]

And I thought my block and plaster walls were weak Vs the solid brick ones.

Personally I'd cut a section out where you want your TV to go and run a couple of battens from floor to ceiling, then put the cut plaster board back over the top, mark where the studs are and secure to those.
You'd never know then. Hope that makes sense.

There is no void though so what you suggest would have to be cutting presumably the first 2 layers away, fitting the battens and then putting board back over. Which involves:

1: Ripping off skirting to get to the floor batten damaging all the nicely decorated wall and paint and plater where it inevitably does not come away nicely
2: Making two vertical cuts with say a circular saw set to 18mm +24mm=42mm depth to only go through the first 2 layers. This would be impossible to complete as you would not get the saw right up to the ceiling or to the floor, so would have to have some of it done with ? some other tool... you can't use a normal plasterboard saw as remember there is no void and you can only go through the first layer. Either way, the amount of dust this would cause in an already habitable bedroom fully decorated and lived in is vast. To get the final cut done to the top/bottom could be possible with a drill used as more of a router moving up through a load of predrilled holes in a line.
3: Installing studs by somehow joining them to the top and bottom battens possibly with right angled brackets in a tight space. Remember they have to go inside and under/over the existing battens.
4: Cut the new plasterboard to size and install over the new vertical studs. Now there is a void of 24mm behind the plasterboard, use this for wires.
5: Mount the bracket using the vertical studs.
6: Make good the wall with filler.
7: Reattach skirting.
8: Redecorate.


That's a lot of work to mount a TV compared to other methods discussed. I would think it would be just as strong but easier to only go through the first layer, and simply put a great big MDF or thick wood board up the same thickness as the first layer just replacing the plasterboard with wood at 18mm thick. Make it go from floor up to as high as the TV mount would be. Just screw directly into it. Still involves taking the skirting off mind.

 

[jaybee]

Personally I would not. No matter how you try, there is a real danger that any movement could rip the mountings out of the plaster. What I would do is make a wooden frame to attach to the wall that transfers the weight directly to the floor. So that would consist of say a 2x2 wooden frame, resting on the floor, and covered with something strong like 12mm MDF. Or indeed just cover it with plasterboard and blend it in with the existing wall so it looks to be part of it. Just remember where the wood is, to screw the TV wall mount to.

I mean I have done this sort of thing before to mount large TV's in the corner of a room where the TV mount simply isn't big enough to reach between the wall and TV. Make a frame out of timber, cover it and paint it. If you put a length of duct pipe in there it also acts as a handy way to cover up all your cables.

Yeah but then the wall never looks like a nice flat wall. It looks.....like you've boxed it up for a TV mount lol.

 

[jaybee]

Use blue Gripit fixings and the Gripit undercutting tool. You can send me the fiver in the post later

https://www.gripitfixings.co.uk/blogs/gripittv/how-to-use-the-gripit-undercutting-tool
https://www.gripitfixings.co.uk/products/gripit-blue?variant=7273849552951

Yeah I had seen this already but I'm not sure it will work in my situation. The gap between first and second layer plasterboard is tiny. I will have a look again but I swear it was like 2mm maybe. There would not be enough space for the grip it fixing arms to pop out... Unless I actually just allowed the tool to go into the second layer as well and cut all that away as well....I guess that could work. Those grip it fixings with the two "wings" that slide out are not great. The really strong fixings are the ones with spring toggles that snap out behind it. Like these.

 

[jaybee]

If you look at the spec sheets you'll likely find Gripit blue's are far higher rated than spring toggles. Gripits have a far tighter fit and spread the vertical load over a greater area of the plasterboard. The wings on both fixings are primarily to prevent pullout, for a TV most of the loading is vertical which is better handled by a gripit.

The undercutting tool is perfect for what you want. Set it at 18mm (or even deeper if you want), use it to cut out the section of 24mm plasterboard beind, then fit the gripits. How big the current gap is doesn't matter, the undercutting tool will just carve out what you need. I genuinely can't think of a more perfect solution other than causing significant damage/modifications to the wall.

If you watch the video in the above link it shows it being used directly over a dab of adhesive on a dot and dab plasterboard wall, which esentially is the same situation you have (i.e. no void)

Hmm. I'm now excited I can get this done and stop being nagged by my son. Yes...I'm a sad, sad man.
I'm intrigued by the grip it's now....I had watched that ultimate handy man guy on youtube test plasterboard fixings to destruction and thought I had seen the "wing" style grip its as I call them to be poor. Will try to find the video now.

Just remembered also the spring toggle ones need a void that is deep enough to actually push the thing into the wall, to allow them to open up. You'd need way more than the 24mm I would have even if I were to wipe out the entire second layer, so spring toggles I don't think are usable. I have used them in a downstairs room which has walls constructed differently (old garage) where the void is suitably large. I used 8 of them on a bracket and it's holding up an older very heavy TV with no issues. I think it weighs about 30kg.

 

[jaybee]

Check this out...

Spring toggles for the win. However...the blue grip its look pretty good for a 20kg modern LED TV and would be the easiest in my situation I feel.

This video also shows installation of a lot of types:

 

[jaybee]

The Geefix ones look like they may be possible to install with minimal void depth actually, since they can be slid in kind of sideways at an angle. But the set tool linked above would not take out a big enough diameter circle as the backplate on them is very wide.

 

[jaybee]

These are very good. I used them to hold up some kitchen wall cabinets.

https://www.toolstation.com/rawlplug-interset-metal-cavity-wall-fixings/p86485

I'd use those to attach a large large MDF board (as others have said) and then attach the TV to it.

Thanks. If you check 8:05 in this video you can see how I think those ones open up behind and grip. I don't think these would work without a void deep enough. If I used these and drilled through into 2/3 layers, they would not expand inside properly. If they did, they would probably jut disintegrated the plasterboard and pull out.

 

[jaybee]

I remeasured the first layer and it does seem to be more standard sized 15mm plasterboard. Then the gap to middle layer is actually more like about 4mm. Maybe the middle layer isn't as thick as 24mm I can't remember when I was inside the other wall lol.
Maybe its: 15mm > 4mm > 24mmm > 4mm > 15mm = total wall thickness of 62mm. Anyway...I've gone with blue gripits, the set tool, a 25mm drill bit and some cheap, sturdy TV brackets. Wish me luck... will report back when I'm huffing and puffing and the wall broke down some time later this week.

 

[jaybee]

Reporting back about 1.5 years too late as I forgot about this, and was inspired by the chat in this other thread
Basically @Abyss was the legend that recommended the blue gripits. For my personal situation with my weird triple laminated plasterboard walls, they were perfect. I now have a 50inch Samsung, a 50 inch Hi Sense and a 65 inch LG OLED in the lounge all hung using standard cheap, sturdy wall brackets with about 8 blue gripits (4 top and 4 bottom) holding the mounts up. They've been up on the walls for the last....well....1.5 years with no issues.