Weird walls with no studs in new build flat

[Essential17]

I’ve just moved into a brand new flat built at the start of this year and it seems to have weird walls I’ve never seen before.

The plasterboard are these massive sheets that are double the thickness of regular plasterboard, and there’s no wooden studs, just metal frame struts every so often.

Myself and the other residents are struggling a bit with putting things on the walls given the lack of wooden studs.

Is anyone familiar with this type of building method — does it have a name?

And most importantly, is it safe for me to put my 70” TV on the wall?

 

[big-all]

paramount plasterboards walls

 

[freddiemercurystwin]

I’ve just moved into a brand new flat built at the start of this year and it seems to have weird walls I’ve never seen before.

The plasterboard are these massive sheets that are double the thickness of regular plasterboard, and there’s no wooden studs, just metal frame struts every so often.

When you say struts do you mean vertical studs?

 

[Essential17]

When you say struts do you mean vertical studs?

Yes.

paramount plasterboards walls

I thought that on an initial search but then a few characteristics people mentioned don’t line up (not old, no egg box behind from what I can see, and seemingly no wooden studs) — although I’ve just found you can have metal studs, so I think it must be this.

Guess I’m gonna have to use some fancy plasterboard fixings.

 

[freddiemercurystwin]

Just sounds like metal stud walls (very common on flats) with 2 layers of plasterboard (also very common) or could be 1 layer 19mm.

 

[Deleted member 174758]

paramount plasterboards walls

Technically, Paramount is a layer of plasterboard, a core of "eggbox" or lattice cardboard then another layer of plasterboard, but there are similar office partition systems some of which are literally two layers of PB back to back with maybe a layer of plastic or metal mesh in the middle. Being so thin some of them have metal H-profile or cross profile joining the sheets together. The door casings tend to be very thin, too, and may even project past the walls noticeably

Those systems will take picture hooks, but aren't really designed to carry a lot of load

OP, how thick are the walls? MF stud goes down to about 50mm, so an MF stud wall might only be 65mm thick with those (50mm of stud with 2 x 6mm PB skins). Smallest timber I've ever used was 38mm, for a 50mm thick wall (with two layers of 6mm PB)

 

[rsgaz]

And most importantly, is it safe for me to put my 70” TV on the wall?

As long as it's not a long arm cantilever type, which extends/tilts/etc, then yes.

If you can centre the bracket on a stud, it will be fine. If you can find a very large bracket which can span two studs, even better. This is the type of fixing you want, whether it's into the plasterboard, or into the stud...
https://www.ebay.co.uk/itm/191148165701

 

[foxhole]

Used those fixings mentioned to mount 85” tv on plasterboard walls.No problem.

 

[Essential17]

Technically, Paramount is a layer of plasterboard, a core of "eggbox" or lattice cardboard then another layer of plasterboard, but there are similar office partition systems some of which are literally two layers of PB back to back with maybe a layer of plastic or metal mesh in the middle. Being so thin some of them have metal H-profile or cross profile joining the sheets together. The door casings tend to be very thin, too, and may even project past the walls noticeably

Those systems will take picture hooks, but aren"t really designed to carry a lot of load

OP, how thick are the walls? MF stud goes down to about 50mm, so a wall might only be 65mm thick on those. Smallest timber I've ever used was 38mm, for a 50mm thick wall (two layers of if 6mm PB)

I‘ve drilled in and the plasterboard seems to be about 20-25mm… would need to double check though.

As long as it's not a long arm cantilever type, which extends/tilts/etc, then yes.

If you can centre the bracket on a stud, it will be fine. If you can find a very large bracket which can span two studs, even better. This is the type of fixing you want, whether it's into the plasterboard, or into the stud...
https://www.ebay.co.uk/itm/191148165701

Thanks. I’ve also read that the snap toggle fixings are good too. I feel like if I use enough of those I should be okay.

I don’t think I can fix anything into the studs seeing as they’re metal… or can I?

 

[rsgaz]

don’t think I can fix anything into the studs seeing as they’re metal… or can I?

Yes, you can. Not as strong as screwing into a nice wooden stud, but, if it were only a small TV, I would just pilot hole into the metal stud and screw a No10 or 12 screw directly into it. Plenty strong enough for something light/medium weight, just as long as it's not a cantilever load, i.e. Don't ever buy floating shelves with your wall type!

As your TV is big, deffo use some dedicated cavity fixings. You need an accurate measurement of the board thickness ideally.

 

[Deleted member 174758]

I‘ve drilled in and the plasterboard seems to be about 20-25mm… would need to double check though.

Assuming that total thickness of the wall is 20 to 25mm then it sounds like a solid partition wall of some description, so there will be no cavity. And if there is no cavity, then cavity wall fixings like snap toggles, drywall plugs, metal hollow wall anchors (what we nickname "umbrellas"), etc simply won't work, because they all depend on having a cavity in the wall which at 20 to 25mm thickness you won't have. Or are you saying that before hitting the cavity there is 20 to 25mm thickness of material (plasterboard), then a void (cavity), then another skin at 20 to 25mm?

I’ve also read that the snap toggle fixings are good too. I feel like if I use enough of those I should be okay.

But where are they going to fit? This is how a snap toggle works:

So you clearly need a 30mm or so wide cavity in the wall to make that work. Same goes for my own preference, the "umbrella" or hollow wall anchor:

I don’t think I can fix anything into the studs seeing as they’re metal… or can I?

The plasterboard are these massive sheets that are double the thickness of regular plasterboard, and there’s no wooden studs, just metal frame struts every so often.

If, as I suspect, this is a partition system, and those "studs" are visible, then they aren't studs at all - they are the connector uprights which link the partition sheets together, and you'll more than likely have all metal inside and outside corners as well, and there may also be a visible track at both floor and ceiling level (although the floor level track will likely be behind a skirting, whilst the ceiling level might be above a suspended ceiling or a beneath some form of cornice moulding). Equally the partition sheets could have a groove machined in all round which fits onto an invisible track.

It would be a help if you could post a photograph of one of these metal uprights, together with an indication of how wide it is. Are the metal "studs" painted or powder coated? How thick are they? Studs are always inside a wall (and so not visible) with the plasterboard attached to the outside faces of the studs - so if yout walls are 20 to 25mm thick you wouldn't be able to have studs or a cavity

These uprights should be drillable, and if aluminium they would almost certainly be tappable (to form a thread), but if/when you leave the property how will you make good the damage? I'm asking because the only residential I've come across with these was a rental-only complex in Manchester where the residents were specifically told (in their agreements) that they couldn't drill the walls

TBH you might be better considering something like an 18mm MDF or plywood pattress fixed to the plasterboard using metal "curly whirly" (self-drilling drywall) fasteners and grip adhesive (e.g. GripFill yellow - the water-based ones will be a better bet than solvent-based in this warm weather). The idea is that with a larger area you can use a number of fasteners, maybe one per 5kg of load, pre-drill the pattress, offer it up to the wall, pre-pilot the wall for the fasteners, insert the fasteners with a hand screwdriver, then put some grip adhesive on the back of the pattress and screw it to the wall and leave the glue to set overnight. This pattress can be painted out, and if you chamfer the edges first it will be even less obtrusive. The TV can then be screwed to the pattress. I have used this technique to fix to system partition walling in offices before where there were no studs and nothing but PB to fix to, and providing the load is close to the wall you are OK, but it will never support something like a deep bookshelf, so furniture like that will need to be free standing

 

[Essential17]

Assuming that total thickness of the wall is 20 to 25mm then it sounds like a solid partition wall of some description, so there will be no cavity. And if there is no cavity, then cavity wall fixings like snap toggles, drywall plugs, metal hollow wall anchors (what we nickname "umbrellas"), etc simply won't work, because they all depend on having a cavity in the wall which at 20 to 25mm thickness you won't have. Or are you saying that before hitting the cavity there is 20 to 25mm thickness of material (plasterboard), then a void (cavity), then another skin at 20 to 25mm?

So the plasterboard itself is about 20mm thick. The cavity behind is about 50mm give or take.

If, as I suspect, this is a partition system, and those "studs" are visible, then they aren't studs at all - they are the connector uprights which link the partition sheets together, and you'll more than likely have all metal inside and outside corners as well, and there may also be a visible track at both floor and ceiling level (although the floor level track will likely be behind a skirting, whilst the ceiling level might be above a suspended ceiling or a beneath some form of cornice moulding). Equally the partition sheets could have a groove machined in all round which fits onto an invisible track.

It would be a help if you could post a photograph of one of these metal uprights, together with an indication of how wide it is. Are the metal "studs" painted or powder coated? How thick are they? Studs are always inside a wall (and so not visible) with the plasterboard attached to the outside faces of the studs - so if yout walls are 20 to 25mm thick you wouldn't be able to have studs or a cavity

These uprights should be drillable, and if aluminium they would almost certainly be tappable (to form a thread), but if/when you leave the property how will you make good the damage? I'm asking because the only residential I've come across with these was a rental-only complex in Manchester where the residents were specifically told (in their agreements) that they couldn't drill the walls

I don’t have much info about the metal uprights. The only reason I know they’re there is because I was drilling into the wall for another purpose and could see the edge of a metal strip on the inside. They seem to be quite thin bits of metal. My first thought was the same as yours — just a frame to hold the plasterboard sheets in place. In which case I imagine they’re not studs I could use for support?

TBH you might be better considering something like an 18mm MDF or plywood pattress fixed to the plasterboard using metal "curly whirly" (self-drilling drywall) fasteners and grip adhesive (e.g. GripFill yellow - the water-based ones will be a better bet than solvent-based in this warm weather). The idea is that with a larger area you can use a number of fasteners, maybe one per 5kg of load, pre-drill the pattress, offer it up to the wall, pre-pilot the wall for the fasteners, insert the fasteners with a hand screwdriver, then put some grip adhesive on the back of the pattress and screw it to the wall and leave the glue to set overnight. This pattress can be painted out, and if you chamfer the edges first it will be even less obtrusive. The TV can then be screwed to the pattress. I have used this technique to fix to system partition walling in offices before where there were no studs and nothing but PB to fix to, and providing the load is close to the wall you are OK,

Thanks, the wood pattress isn’t a bad idea. My TV isn’t actually that heavy despite being so big. So I think I will find out the weight of it and determine if I think it’s needed or if cavity fixings like snap toggles will be sufficient.

but it will never support something like a deep bookshelf, so furniture like that will need to be free standing

Gosh, I wish someone had told me that a week ago!

 

[Deleted member 174758]

So the plasterboard itself is about 20mm thick. The cavity behind is about 50mm give or take.

In that case it sounds like a double-boarded cavity wall. Double-boarding is done for improved thermal efficiency, improved soundproofing and improved fireproofing (as in partition walls between two adjacent apartments)

I don’t have much info about the metal uprights. The only reason I know they’re there is because I was drilling into the wall for another purpose and could see the edge of a metal strip on the inside...

...In which case I imagine they’re not studs I could use for support?

In that case you are dealing with a metal stud wall, and the metal is pretty thin (under 1mm for non-structural walls). I gained the (erroneous) impression that you could actually see the uprights on the outside of the wall (hence the partition wall theory). Metal studs on their own won't carry any load, but screw two 12mm layers of PB onto them (forming a stressed skin) and they can.

The best way I know to find studs (metal or timber) is to move a rare earth magnet across the wall - it will find the screws, but do bear in mind that screws can be at 200 to 300mm vertical spacing and that domestic studs are normally set on 600mm centres. Also, with double skin walls there is sometimes the possibility that you can hit a metal fixing strap (e.g. Gypframe GFS) - but the way you can tell it is a fixing strap is that these are only ever between the two layers of PB at one thickness (10 to 12mm) below the surface.

This means that your studs are useable to carry the weight of the TV. The main downside is that you either need to use metal (fine thread) drywall screws to fix to them (coarse thread wood-type drywalls may not be able to pierce the metal) or alternatively a good quality 4.0mm wood screw, like these Spectre screws can be used. The reason for 4mm, not larger, is that a 4mm wood screw can drill through MF, with thicker screws you'll often struggle. The Spectre screws I linked to (together with more premium screws such as Spax or Reisser Cutter screws) have what is called a "slash point" which cheapo screws lack:

Thanks, the wood pattress isn’t a bad idea.

I've used pattresses to carry monitors on solid (no-cavity) office partition walls in the past, partly because by spreading the load across a lot of fixings you can carry a much greater load than the four or six fixings in a relatively small area that some TV brackets have.

Where I deal with cavity walls, which we now know yours to be, my own preference is for "umbrella" (hollow wall) fixings over toggles. I admit this is partly historical - I have had the setting tool for a few decades (which cost about a tenner) and I've found them reliable in the shop fitting environments I used to work in. I've also have book shelves at home on Spur shelving where alternate uprights are only onto "umbrellas" (no stud behind them) - they've been up for about 25 years now (on double 12.5mm PB). The trick to making this sort of thing work is always to spread the load over the biggest possible area with more screws than you actually need to carry the load. That way everything is understressed

 

[Essential17]

In that case it sounds like a double-boarded cavity wall. Double-boarding is done for improved thermal efficiency, improved soundproofing and improved fireproofing (as in partition walls between two adjacent apartments)

Your points here have made me a bit concerned on an assumption I had before…

The cavity space I found before IS on a partition to the apartment next door. I had assumed it would be the same with our internal bedroom partition wall that I intend to put the TV onto. Both walls are 100mm in thickness though, so I expect they’re constructed in the same way…(?) I’ll have to drill in and see!

Thanks for all the advice. I think my best course of action is to use a rare earth magnet to find where the studs are on the wall — if their positions can work with the TV bracket I will get some of those special screws to get into the metal studs, but otherwise will consider the pattress approach. Although, from a bit of research, I’ve found snap toggles apparently can withstand more than 100kg of force each, and the TV is only around 25Kg, so I might just investigate those a bit further and see how robust they really are.