What screws for specific task.

[colinuk1]

Hi guys,

I have been given the job of putting three bathroom cabinets up in a family home. The walls are plastered on top of brick.

The cabinets are heavy, and the supplied fixings look a little underwhelming to me - just 2 4x30mm screws.

I'd like to use a bigger screw, but the 4mm heads supplied just about go into the keyhole brackets on the back of the cabinets. A bigger headed screw would not fit.

Ideally, I guess I need a 6 x 50 screw with a size 4 head. Or something, but cannot find any such thing.

Any ideas?

 

[big-all]

brown plugs [assuming they are ]are only 38mm deep so assuming key hole will put the head about 5mm away from the wall surface that will be fine providing the wall isnt crumbly
sorry just noticed 30mm i would go for 4mm x40/45mm[no8x 1 3/4"]

 

[Deleted member 174758]

The cabinets are heavy, and the supplied fixings look a little underwhelming to me - just 2 4x30mm screws.

Ideally, I guess I need a 6 x 50 screw with a size 4 head. Or something, but cannot find any such thing.

6.0mm screws are more for structural work than putting up a bathroom cabinet, and the heads are the size they are because with a 6.0mm screw you need a bit more holding power.

As B-A says, a 4.0mm screw in a longer length should suffice, but you do need the plug to be pushed into the brickwork, not be inside the plaster. Assuming amodern house the plaster won't be all that thick unless it has been boarded over dot and dab, so as he says a 50mm screw should do.

 

[bernardgreen]

If the plasterboard is fixed by dot and dab to the brick then there could be a significant space between plaster and brick. Over tightening the screw may result in the plasterboard cracking. Fitting a spacer as below removes pressure from the plasterboard.
Green is the cabinet, and gray ( insulation ) is the significant space

The spacer does not have to be round.

 

[opps]

If the plasterboard is fixed by dot and dab to the brick then there could be a significant space between plaster and brick. Over tightening the screw may result in the plasterboard cracking. Fitting a spacer as below removes pressure from the plasterboard.
Green is the cabinet, and gray ( insulation ) is the significant space

View attachment 249374

The spacer does not have to be round.

I did recently purchase a box of Corefix dot'n'dab fixings. £20 for 24 fittings though. They have a metal sleeve that helps distribute the load in to the wall. The plug is sufficiently long enough to ensure that you do not distort the plasterboard as you tighten the screw. The downside is that the collar sits slightly proud of the plaster.

 

[foxhole]

If the plasterboard is fixed by dot and dab to the brick then there could be a significant space between plaster and brick. Over tightening the screw may result in the plasterboard cracking. Fitting a spacer as below removes pressure from the plasterboard.
Green is the cabinet, and gray ( insulation ) is the significant space

View attachment 249374

The spacer does not have to be round.

What plasterboard?

 

[bernardgreen]

What plasterboard?

I accept I mis read the original post. But even plaster direct to brickwork can crack / crumble when under pressure.

 

[big-all]

I accept I mis read the original post. But even plaster direct to brickwork can crack / crumble when under pressure.

i frequently misread posts even ones as simple as the origional post

 

[JP_]

Maybe fix it with the supplied screws, which might be enough if you can drill a nice neat hole for the plug, and then pop in a couple of additional fixings of your own

Maybe a couple of these somewhere discreet with a longer screw and plug
https://www.wickes.co.uk/Wickes-Plastic-Fixit-Block---White-Pack-of-24/p/164410

 

[opps]

but you do need the plug to be pushed into the brickwork,

Whenever I have pushed a plug deep into the brickwork, the screw invariably pulls it out. There have been times when I have used two brown plugs to create a super long plug....

In all seriousness I don't think many people, including the people that design things intended to be fitted to walls take that in to account. Any gap between the fitting and the wall, by definition creates a cavity and runs the risk of pulling the fitting out of the wall as the screw is driven in, or as hinted by @Bernard, might lead to distortion.

 

[catlad]

I almost always chuck away any fixings supplied as they are generally rubbish!

 

[opps]

I almost always chuck away any fixings supplied as they are generally rubbish!

Agreed, they often don't seem to be either posidrive or phillips screws. I have long wondered if they are JIS screws.

 

[conny]

Agreed, they often don't seem to be either posidrive or phillips screws. I have long wondered if they are JIS screws.

Never heard of JIS screws so watched the video. Nice bit of knowledge stored away for future use. Good idea about looking for a dot on the screw.
Mind you, like someone else said, I never use supplied screws because the feel/look cheap and nasty.

 

[big-all]

i never use the supplied screws or plugs for fixing to walls or other material you eyes see the plug colour and your brain does the rest no thinking no calculations no thought why learn something new that serves no purpose especially if you dont know the quality off cheese used
what wrong with red plug 38mm hole 5-5.5mm masonary no 6 or 8
or brown 6-6.5mm 45mm hole no 8 or 10 screw

 

[Deleted member 174758]

Never heard of JIS screws so watched the video.

If you buy Makita or Hikoki kit all those nice "Phillips" screws are in fact JIS

...what wrong with red plug 38mm hole 5-5.5mm masonary no 6 or 8
or brown 6-6.5mm 45mm hole no 8 or 10 screw

Whilst I agree with you about the ease of colour coding for plugs, if you use a 6mm bit to drill a hole in anything other than cream cheese, it'll be too tight for a British brown plug (we"ll leave Fischer out of this for now) which requires a 5/32in hole - or 7mm. So if your 6mm bit is working it must be doing a great impression of a single blade helicopter...

OP - in metric terms brown plugs are for use with 4.5, 5.0 and 6.0mm screws. Metric 4.0mm screws (which are slightly smaller than the old #8 size) can be a bit loose in them I find