Fixing Kitchen wall unit to thick plasterboard

[veedee]

I will be installing some 600mm wall units to some plasterboard and wanted to know the best fixing

The plasterboard is pink (fire resistant) and it is thick

The total thickness of the PB is 35mm

And it appears to be comprised of two pieces of plasterboard that has been stuck together.. There is insulation behind all of this too

The original screw used in the old wall cabinet was 60mm (looks like a black drywall screw)

Will i need a plasterboard fixing for this? And if so, what should i use

After the insulation, there is PB of the adjoining flat

 

[rsgaz]

the best fixing

The best fixing for any stud wall is finding the studs and screwing into those, with a continuous rail.

There is insulation behind all of this too

Rigid foam stuff like celotex, or rockwool/fibreglass type? i.e. is there space behind the boards for this type of fixing to be able to open out once inserted?

http://www.ebay.co.uk/itm/360502666901

 

[veedee]

@rsgaz thanks for the response

There are metal studs, however with the way the kitchens designed, it will not be possible to hit these all the time

If i used 6x heavy duty fixings like the ones you linked to, will this suffice? Also, i was considering using snap toggles as i heard that these are incredibly strong


And the insulation is the rockwool/fibreglass type

 

[rsgaz]

If i used 6x heavy duty fixings like the ones you linked to, will this suffice?

Yes, this type are the best when the screw holes need to be close together, they have the smallest drill size, so don't weaken the boards as much, right where you want strength.

Also, i was considering using snap toggles

Snap toggles, spring toggles and the above type will all be fine, but each have their downsides...

Toggler - they are expensive and the plastic flange sticks out a bit. Large drill size (13mm) also.
Spring toggles - Large drill size, with no front flange part, so there is loads of play when tightening up. If you need to take them down in future to decorate for example, the threaded part falls down inside the wall.
Brolly type - metal flange sticks out a tiny bit and you ought to buy the setting tool for them, so more initial cost.

Double skinned plasterboard is actually surprisingly strong, especially under a shear load, rather than a 'pull-out'/cantilever load. If you were to use the continuous rail idea, then plenty of number 10 screws into ordinary brown plugs would easily hold a quarter of a ton! Spreading the load is more important with plasterboard, especially as you unfortunately have steel studs.

Using a continuous rail also makes it so much easier to get everything level and lined up properly.

Gaz

 

[veedee]

That's brilliant, thanks for your advice.. i will have to do my homework on the continuous rail to be honest.. As i am not to familiar with this..

 

[rsgaz]

Oh, and one more downside to the brolly type (despite which you have probably guessed are my favourite), you need to buy the correct size for the thickness of the wall, which in your case, fortunately, you already know is 35mm, so the ones I linked to are spot on.

The other types do handle various wall thicknesses a lot easier than the brollys.

 

[veedee]

@rsgaz out of curiosity, can i ask why you're such a fan of these?

 

[rsgaz]

why you're such a fan of these?

Look at the back of this offcut of plasterboard I did a test on ages ago.
See how great they spread the load over a large area, even when two fixings are needed very close to each other...

Now, spring toggles. Pause this video at 1:43, as he is removing the toggle. Look at the 4 sharp bite marks it has left behind. Bear in mind that plasterboard is just paper on the outside layers, you can see why I don't like them...

And also, go back a bit and pause at 1:30, look at the diameter of the hole that was needed to push it through in the first place. So when you're first screwing them up tight, trying to line things up to within a mm or so, there is just too much play. And imagine trying to install two spring toggles at the same time with a bracket that needs two fixings close together, seeing as you have to have them both threaded through the bracket already, before you can pass the toggles through the wall.

 

[rsgaz]

Snap toggles (Toggler) - These are a close second in my opinion, they do spread the load nicely because it's a flat bar that presses against the back of the board, not sharp pointy bits! Again they need a larger hole and pause this video at 1:13...

You can see how the plastic flange part sticks out the front quite a bit. I don't like that for putting up small items, you want them to be tight to the wall.

The main reason they come second for me though is the cost per one. They are a lot more than brolly fixings per one, but as I said earlier, you really want the 'setting tool' for the brolly ones, so there's that cost to think of too.

For me personally, seeing as I use the brolly fixings at work, there are no downsides at all, I already have the setting tool, I already have an assortment for different wall thicknesses, etc. For a DIY-er, if you have quite a few things to put up in a new home for example, the initial cost of the setting tool will soon be saved back by the cheaper price of the brollys.

HTH

Gaz

 

[rsgaz]

And finally, to prove I'm not totally biased towards brollys, here are some figures I've just measured...

Although the flange on an M6 brolly is 0.8mm thick, when tightened up, it only protrudes out by 0.25mm from the wall.

So, only the spring toggles have zero flange, but their other issues are why I won't use them.

 

[veedee]

@rsgaz Top man! I'm totally sold... Thank you for your help..

You're a star!

 

[rsgaz]

Now you just want the tool, then...

Cheap n cheerful...
http://amzn.eu/5D5VYZ9

Much better quality...
http://amzn.eu/gbFDozP

 

[veedee]

Now you just want the tool, then...

Cheap n cheerful...
http://amzn.eu/5D5VYZ9

Much better quality...
http://amzn.eu/gbFDozP

Would this be suitable from screwfix? Because I'm not sure whether i can hang around for delivery

https://www.screwfix.com/p/setting-tool/12429?_requestid=158355


Also the plasterboard is 35mm.. Can you confirm that M4 60/65mm would be suitable?

I assumed that i would need a fixing closer to 35mm such as

https://www.screwfix.com/p/easyfix-hollow-wall-anchors-m5-x-52mm-100-pack/5643p

Or is anything above 35mm okay?

 

[rsgaz]

Would this be suitable from screwfix?

Yes, but that is identical to the cheap one I linked to which is £6.29 on Amazon or eBay.

Can you confirm that M4 60/65mm would be suitable?

Scroll down in the eBay listing I linked to, to where it says "Grip Range" in red letters. 60mm is the initial length of the anchor, 65mm is the length of the screw. But when it scrunches up, it suits a wall thickness of 31 to 38, which is bang on what you need.

Gaz