can I hang kitchen wall units on a stud wall using size 6 screws and rawl plugs? (denoted “medium weight”) by B&Q

I wouldnt. You can get a lot of weight in a cupboard. You’ll need something in the heavy weight division. Commercially you would board out your wall with plyboard beforehand.

They are barely keeping my curtain rail up, so no!

yeah am thinking some wood screwed to the studs would be stronger

I guess if you were looking for an insurance claim to replace all you crockery & glassware you would consider it for a few moments.

screwed to the studs would be stronger

What, you weren’t going to screw into the studs ? 😯

Use at least an 8 if not a 10 screw. And at least 1 1/2″ long if not 2″.

I secured the base units with them and they felt pretty solid.

Ok maybe not that solid…

Studs don’t line up with units

You need to find something solid to hang them from prefereably but another way if the cupboards need to go flush to the wall and your studs are not in the right place is to hang them on the rawlplugs then run a batton ( use moulding to suit the style of the cupboards ?) along the bottom of the cupboards so they sit on it – you should be able to get fixings into the studs for the batton. The batton takes the weight – all the usual cupboard fixings are doing is stopping them falling forward. still not perfect.

Of cut into the plasterboard behind the cupboards and put studs in in the right place – horizontal ones screwed into the vertical studs flush with the wall surface.

No6 screws and Rawl plugs? Into plasterboard?

Hell all my units are held on with M8 Rawl bolts into solid brick and i was still mildly nervous.

Defintely get some no10 or 12 screws through the board into the stud. If there’s a few places you can’t do that, have a look at the fixings section in the screwfix catalogue – should give you some ideas for what’s the right thing to use for a given material.

Uh ok the rawl plugs are 10mm. Good tip tj, I may combine that with a thinner batten behind

If you were seriously planning on doing it with medium weight rawl plugs and screws, I’d suggest doing it with no more nails instead. Will have broadly the same effect, and will take far less time.

Also, save more time by not bothering to line them up and hang them straight this go around. Save that for the next go.

then run a batton along the bottom of the cupboards so they sit on it

Sorry TJ if I’m reading that right, then that would be more or less completely useless. It’s the top of the wall unit which pulls away from the wall, not the bottom.

Although your suggestion of cutting out the plasterboard and fixing some noggins is a good idea imo. Specially if there’s no making good needed as it’s all hidden behind the unit.

Why can’t you line up the screws with the studs cynic-al ? Have the wall units got those metal adjustable corner thingymajig-type fittings ?

GG – the batton underneath takes the weight – vertical load – the top fixings merely stop the cupboards pulling forward off the wall – not a perfect solution but do the geometry – the outward force pulling the top fixings out will be much less than the total downward force.

Sorry TJ if I’m reading that right, then that would be more or less completely useless. It’s the top of the wall unit which pulls away from the wall, not the bottom.

Nope. TJ is right, the baton along the base will support the weight of the cupboard plus contents. The fixing at the top of the cupboard will stop the cupboard coming away from the wall but will take no real strain.

Studs will be at either 400/500/600mm centres and therefore are not easily ‘lined’ up for fixing purposes unless you want uneven spacings….

The fixing at the top of the cupboard will stop the cupboard coming away from the wall but will take no real strain.

Now that, is completely wrong. It is quite normal to have just two fixings at the top of a wall unit and none at the bottom. However, you could not hang a wall unit with just two screws at the bottom and none at the top.

The reason for this, is that the fixing at the bottom takes no real strain, it is the fixings at the top which do all the work.

In the same way that the top hinge takes all the weight of a door, and the bottom hinge does little, if any, work.

can I hang kitchen wall units on a stud wall using size 6 screws and rawl plugs?

You don’t need rawl plugs when screwing into studs, you could drill a pilot hole with a drill size slightly smaller than the shaft of the screws.

LOL at all the misunderstandings and sarcasm.

Thanks for the tips tho, I think tj’s idea combined with cutting some plaster away for a strap behind the fixings may work. Oh and I don’t see how the bottom hinge of a door takes hardly any weight

GG – you misunderstand. If you hang the cupboard from the top it will be fine for sure and that is the best way.
However if you put fixings at the bottom and let the cupboard rest on them they will take the vertical load. As these fixings are at the back and bottom but the weight acts some distance out from the wall you will be left with a rotation around the bottom fixing which effectively acts outwards at the top as the cupboard tries to rotate around the bottom fixing. Hence you get an outward force at the top. The top mountings then only take this outward force and it is lower than the total downward force.

Its quite a normal way of fixing wall cupboards. I used to fit kitchens for a living

How old is the house? i bought a shitty new build once (built 2001) try putting anything on those walls! breeze blocks with plasterboard stuck on with dollops of concrete grrrrrrrrrrrrr only a few centemeters between the two so nightmare – i never thought of or found a way to secure anything to those walls.

Nope. TJ is right, the baton along the base will support the weight of the cupboard plus contents. The fixing at the top of the cupboard will stop the cupboard coming away from the wall but will take no real strain.

It’s like QR wheel ejection all over again…

Unless the batten has significant depth it’s going to act largely as a pivot – the centre of gravity of the unloaded cupboard (let alone one full of heavy stuff) will be massively further forward than the forward lip of the batten itself. If your cupboard’s height is around twice its depth then you can approximate up to half the weight acting to pull the screw/plug out of the wall. It’s still going to require something significantly stronger than a size 6 screw/plug into plasterboard…

You really need to insert a reasonably sized piece of wood horizontally behind the plasterboard, securely fixed into the vertical studwork. This should be at the height of the fixing points for the wall cupboards. Reinstate the plasterboard, then screw through for each cupboard into the horizontal.

House – 1923, stud wall – late 2008.

Know what you mean, lath and plaster is similar in a sense.

i bought a shitty new build once (built 2001) try putting anything on those walls! breeze blocks with plasterboard stuck on with dollops of concrete grrrrrrrrrrrrr only a few centemeters between the two so nightmare – i never thought of or found a way to secure anything to those walls.

It would have been drywall adhesive rather than concrete, but yes these type of walls are a bit of a pain. On very modern houses the block behind the plasterboard is often the aerated type which are very light and have great thermal properties, but won’t hold a rawlplug particularly well either. To fix anything substantial you need looooong screws and plugs to get through the board, void and deep enough into the block behind.

Forget all the suggestions above except the noggins.

Cut the plasterboards out and insert some 4×2 noggins, 4″ being face out.

Cut the pieces just large enough so you need to hammer them in slightly tight, not so you’re moving the studs much though. Then screw these into the studs at 45 degrees with a couple of 4x80mm screws at each side. A 5mm screw may split the wood.
then just re-attach the cut out pieces with gripfill of the like. It won’t be on show so no need to bother skimming up etc. If you screw the boards back, make sure they won’t interfere with the cabinet hanger screws.

Then just use 5x50mm screws to hand your brackets.

Good quality screws are always worth the extra btw, spax, rapier, goldscrew plus and turbo gold, reisser, all very good and VERY Expensive in B&Q

Shouldn’t take long and will be permanent.

I used “bigassscrews” with rawl plugs straight into brick, and also bracketed underneath to take the weight.

My units will then be sticking out 2″ from the wall TFM, unless I am missing something?

M-You are correct in that its like the QR thingy – its about geometry and force vectors and stuff and most folk cannot grasp it.
Yes the batton will act as a pivot. However the downwards force will be acting from the centre of the cupboard assuming evenly loaded. the top screw will be resisting the rotation from the top of the cupboard.

You can do this experimentally. Get a book and put the bottom corner on the edge of a table. – it will rotate forwards. Support it at the front ednge that will be half the weight for sure but support it at the top by stopping it rotating forward – there it is a much smaller outwards force due to the way the angles are. between 1/4 and 1/8

I could draw it all out for you with vectors and stuff. I cannot explain it well without going into complex algebra ( which I would have to bone up on)but the outward force at the top of the cupboard ends up nowhere near half the weight – its a far smaller figure due to the various angles the forces act thru.

What funky monkey suggests is the best way bar far.

Al – want me to pop round and show you? doing what he suggests ( and I did as well 🙂 ) will give the strongest mounting and you still end up with the cupboards flush to the wall.

Use Driva fixings. Metal ones not the plastic versions.

I have done this on a few occasions. TJ and FM are both right.

Now that, is completely wrong

Oh really GG……????? Best go and check all those hundreds of wall units I’ve fitted over my many years as a cabinet maker…… bugger 😀

cynic,

the noggins fit inside the existing studs

Cheers TFM – I get it now, and thanks TJ, I’ll be fine (Will probbers use your method)

Oldgit – They really don’t look strong enough.

its a far smaller figure due to the various angles the forces act thru

I agree that it’s unlikely to be as much as half, but that is the potential maximum for the situation I described. It largely depends on where the cupboard is loaded and how deep the batten is, as well as the aspect ratio of the cupboard. There should, however, also be a significant safety margin built in for things like a child pulling down on a cupboard door whilst opening it.

In any case I don’t believe that it’s sufficient to install a kitchen wall cupboard (which someone could very easily load with 10-20Kg of crockery) using a batten along the bottom and the top fixed into plasterboard.

The only sensible solution is as per TFM.

Oh and I don’t see how the bottom hinge of a door takes hardly any weight

I’m only guessing, but is maybe because you haven’t hung many doors ?

Best go and check all those hundreds of wall units I’ve fitted over my many years as a cabinet maker.

I would really love to – if it’s not too far. I’ve never seen wall units without screws at the top because it’s the ones at the bottom which do all the work. It must have saved you a lot of time on those hundreds of wall units you’ve fitted, not having to get up onto your stool to fix screws at the top of the unit.

No, wait, I’ve just remembered : “The fixing at the top of the cupboard will stop the cupboard coming away from the wall but will take no real strain”

So maybe little piddling number 6 screws at the top just to ” stop the cupboard coming away from the wall” (that should reduce the effort associated with high-level drilling) and then big hefty number 10s at the bottom to take “the real strain”, eh ?

btw, I mentioned your theory at work today ……… oh how we laughed.

Blimey, top rant GG, makes little sense, only short of a few caps and some swearing. I genuinelyt have no idea what you are on about after the first sentence.

Unfortunately posts like this undermine any decent arguments that someone has previously made…

You’re getting the wrong end of the stick cynic-al – no ranting on my part, I’m actually finding it all rather amusing 😉

I’m waiting for someone to come along and tell me that on big 2 hour ****-off doors, you put two butts at the bottom (because that’s where the ‘real strain’ is) and just one at the top (because there’s no ‘real strain’ there) Now that would cheer me up even more 8)

GG – its you that are getting the total wrong end of this one.
I’m sorry you can’t understand my explanation but I can’t explain it any better than I have above without a diagramme. Look at where the forces act and do the vector addition. if you have a really solid mounting at the bottom then the top mounting will only take a small outward load. approx 1/4 – 1/8 of the weight in the cupboard. Think of it like a cantilever perhaps?

Its not a great solution but often the only one where fixings are hard to do.

Its clear from your answer above that you don’t understand the point at all.

Yeah I know exactly what you mean TJ. And your theory would indeed work very well on something like a wall mirror. But we’re talking about kitchen units here – something which has a significant depth to it. So in the case of w/units, the idea is a non-starter imo. By far the best solution is the one which you also suggested, of cutting out the p/board and noggin out. Although I’ve yet to be convinced that at least one stud per unit can’t be located, but then we don’t even know the widths of the w/units. BTW it’s a shame that a wall only a few months old wasn’t nogged out when it was erected 😕

And try not to take it too seriously TJ no need for diagrams etc, it really isn’t that important to me, and cynic-al appears more than happy with the advice he’s been given. If I’m taking the p1ss it’s only because I’m finding it all slightly amusing – but I’m really not bothered 8)

Although I quite fancy a challenge with my ‘heavy door’ 🙄 😉

GG – sorry mate – you clearly don’t understand. Just because you don’t understand doesn’t mean its wrong. Yes the cupboard has depth – so the downward force acts from the centre of gravity – half way up and half way out ( assuming even loading)

Thus say you have a weight of 40 kg in the cupboard and the cupboard is 40 cm deep. and 80 cm high. This gives a downward force of 400 N acting straight down at 20 cm from the edge and 40 cm from the bottom. You are resisting this force from the back edge at teh bottom

Obviously this is out of balance – the cupboard will want to topple forward. Effectively this is a pull forward of 200 newton by vector addition( actually a chunk less but I can’t be arsed working out the geometry sine, cosine and stuff)acting directly forward 40 cm from the bottom of the cupboard ( thru the centre of gravity remember)to resist this pull of 200 N forward you have a fixing at the top – now this has a 2:1 leverage ratio – as it is a turning moment – hinge at the bottom back and toppling forward so the pull forward at the top is <100N.

So you are using the top fixing to resist a pull foreward of under 100N ( 10KG) which is why you can get away with a less secure fixing.

LOL !