# Radiator on studs on top of bricks



## phloaw (24 Jul 2021)

I need to hang a radiator (160cm wide, 50cm high, total weight around 35kg) via two brackets to a plasterboard wall.
The wall is external, so that it has *studs* (about *12mm deep* and 50mm wide) behind the plasterboard and then *bricks* behind the studs.
I am lucky enough to have studs in correspondence of my brackets.

However, I was wondering whether the 12mm depth of the studs would be *enough for the screws to bite*, or if I should reach to the bricks behind the studs and fix the brackets to them.

If I can use the studs, how do I make sure that the screws go through the whole 12mm, given that this will be prevented by them hitting the bricks?

Thanks.


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## Cabinetman (24 Jul 2021)

Debatable but I think if you use as many holes as you can in the brackets it will work ok to just to go into the timber rather than straight through into the brick, the plasterboard is probably 12 mil (well it should be on a wall) plus the 12mm timber and probably a millimetre for the bracket so 1” screws should be fine. Ian


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## Doug B (24 Jul 2021)

Personally I'd have gone through the timber & fixed into the brick, 12mm isn't enough in my book plus the unknown of how well the studs are fixed to the bricks & I'd rather be safe than sorry.


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## phloaw (24 Jul 2021)

Doug B said:


> Personally I'd have gone through the timber & fixed into the brick, 12mm isn't enough in my book plus the unknown of how well the studs are fixed to the bricks & I'd rather be safe than sorry.



Thanks. I've no experience with brick walls. One problem is that, due to plasterboard, I cannot see whether I drill through bricks or mortar. Would that matter?


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## Doug B (24 Jul 2021)

That would depend on the state of the mortar, but there are usually a few slots & holes in rad brackets so if you hit a soft horizontal mortar joint use another hole


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## phloaw (24 Jul 2021)

Doug B said:


> That would depend on the state of the mortar, but there are usually a few slots & holes in rad brackets so if you hit a soft horizontal mortar joint use another hole


How do I know whether I hit the mortar?


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## Doug B (24 Jul 2021)

The dust is a lighter colour plus if you hit it & it's hard you're fine getting a fixing in it


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## Misterdog (24 Jul 2021)

phloaw said:


> How do I know whether I hit the mortar?



The screw will deform the bracket if the fixing is strong enough. 
Using the correct size screw/wall plug and drill even the mortar should hold though I would fit 3 screws in each bracket anyway.
Use the slots first, hang the rad and level it by tapping the bracket, remove rad then add more fixings in the fixed holes.

7mm masonary drill brown plugs and 60/70mm screws, dome head preferably, or washers to spread the load on the bracket.

How much does the rad weigh when full of water


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## phloaw (24 Jul 2021)

Doug B said:


> The dust is a lighter colour plus if you hit it & it's hard you're fine getting a fixing in it


Thank you! Can I ask a final question, please?
If I fix to the bricks, should I avoid the battens and screw directly into bricks? I can do that by slightly shifting the radiator horizontally, which would be ok.


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## phloaw (24 Jul 2021)

Misterdog said:


> The screw will deform the bracket if the fixing is strong enough.
> Using the correct size screw/wall plug and drill even the mortar should hold though I would fit 3 screws in each bracket anyway.
> Use the slots first, hang the rad and level it by tapping the bracket, remove rad then add more fixings in the fixed holes.
> 
> ...



Very useful, thanks! If you could also answer the question I asked Doug above, that'd be grand.
I'd say not more than 40kg including the water weight


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## Misterdog (24 Jul 2021)

Not necessary though you may need to use a HSS drill first before the masonary drill, I would just turn off the SDS on my drill until I hit the brick.


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## Misterdog (24 Jul 2021)

The good news is with a plasterboard cavity you shouldnt get horrible red brick dust staining all the decorating and carpet.


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## phloaw (24 Jul 2021)

Thanks everyone. I think I'll shift the radiator a bit to avoid studs (that will even look better, more symmetric with the window above) and fix to bricks using your advice. Will let you know. Please feel free to give further advice, if there's any.


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## Misterdog (24 Jul 2021)

If you avoid the timbers don't 'bend' the plasterboard........

You could always fill the void behind the brackets with some expanding foam, if you wanted to stiffen it up.


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## phloaw (24 Jul 2021)

Misterdog said:


> If you avoid the timbers don't 'bend' the plasterboard........


Which amounts to not tightening the screws too much, right?


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## J-G (24 Jul 2021)

phloaw said:


> Thank you! Can I ask a final question, please?
> If I fix to the bricks, should I avoid the battens and screw directly into bricks? I can do that by slightly shifting the radiator horizontally, which would be ok.


If it were my job I'd make sure that I didn't 'avoid the battens' ! Worst acceptable position (for me) would be that the screws_* just *_missed the battens.

As has been mentioned, screwing between the battens leaves you wide open to deforming the plasterboard and not having a firm/solid fixing.


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## phloaw (24 Jul 2021)

J-G said:


> If it were my job I'd make sure that I didn't 'avoid the battens' ! Worst acceptable position (for me) would be that the screws_* just *_missed the battens.
> 
> As has been mentioned, screwing between the battens leaves you wide open to deforming the plasterboard and not having a firm/solid fixing.



Sorry, I'm confused: are you suggesting to screw to the battens only or to the battens AND the (plugged) bricks?


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## Misterdog (24 Jul 2021)

Some plumbers would only use heavy duty plasterboard fixings.

Easyfix Hollow Wall Anchors 8-16mm M5 x 52mm 10 Pack

Though you need the spreader tool and would still have to drill the brick for the fixing length.


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## Sachakins (24 Jul 2021)

Try aiming for fixing to go through batten and into the brick also.


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## J-G (24 Jul 2021)

phloaw said:


> Sorry, I'm confused: are you suggesting to screw to the battens only or to the battens AND the (plugged) bricks?


No - screw through the battens into the brick - I've drawn a guess as to what I would do given the brief information available. :--




Although I've drawn Round Head Screws you may be using C/Snk and I've no idea how thick the brackets are nor how wide or what the spacing of the battens is but I hope the method I propose is clear.


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## phloaw (25 Jul 2021)

J-G said:


> No - screw through the battens into the brick - I've drawn a guess as to what I would do given the brief information available. :--View attachment 114624
> 
> Although I've drawn Round Head Screws you may be using C/Snk and I've no idea how thick the brackets are nor how wide or what the spacing of the battens is but I hope the method I propose is clear.


Amazing that you drew a sketch! And your guess is accurate.


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## Woody Alan (25 Jul 2021)

You could always try the appropriate fixings for dot and dab Corefix Metal Origional Heavy Duty Dot & Dab Wall Fixing 10 x 95mm 24 Pack They come in different sizes and have a steel support tube to avoid crushing plasterboard.


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## 1steven (25 Jul 2021)

phloaw said:


> I need to hang a radiator (160cm wide, 50cm high, total weight around 35kg) via two brackets to a plasterboard wall.
> The wall is external, so that it has *studs* (about *12mm deep* and 50mm wide) behind the plasterboard and then *bricks* behind the studs.
> I am lucky enough to have studs in correspondence of my brackets.
> 
> ...


This should do you. Fischer SXR Hexagon Frame Fixings | Frame Fixings - MIDFIX


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## J-G (25 Jul 2021)

phloaw said:


> Amazing that you drew a sketch! And your guess is accurate.


I don't consider a sketch 'amazing' in any way - it's the way I work. If you can draw a 'problem' then you are more likely to understand the issues involved in the solution - or - as my father said many times "If you can draw it Lad, you can make it".

As Confucius apparently said, "A picture is worth a thousand words"

My guess being accurate is more down to your initial description, which, although sketchy, did provide the salient information.

There may be more appropriate solutions of course, I haven't investigated the various 'Plaster-board' fixings that have also been proposed.


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## CornishWoodworker (25 Jul 2021)

12mm isn't a lot but if you use screws and use a construction adhesive between bracket and plasterboard, that should suffice.


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## Daniel2 (25 Jul 2021)

CornishWoodworker said:


> 12mm isn't a lot but if you use screws and use a construction adhesive between bracket and plasterboard, that should suffice.



That's the way I was taught.
Mollys into the plasterboard and glue between bracket and plasterboard.
IMO, fixing into the bricks may cause a hydraulic bridge for damp.


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## Misterdog (25 Jul 2021)

Daniel2 said:


> Mollys



?


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## Daniel2 (25 Jul 2021)

Misterdog said:


> ?









AKA drywall anchor.


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## Misterdog (25 Jul 2021)

Never heard them called that before, is it a French term?


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## johnny (25 Jul 2021)

forget hanging your radiator on the plasterboard or just the battens as some have suggested .
It is not a sensible option for such a lot of weight.

Using plasterboard fixings to hang heavy items like radiators and wash hand basins should only be used as a last resort when there is not a more substantial substrate to fix to.

The first time someone uses the radiator to pull themselves upright after kneeling on the floor it will rip the fixings straight out of the plasterboard.

Fix the radiator brackets in the manner that J-G has outlined in his excellent sketch and you will never have the worry of the brackets coming loose or the radiator coming off the wall .

Before I became an Architect I was a Plumber and Corgi C Heating Engineer for many years and fixed many thousands of radiators and wash basins to all manner of walls . The number of times I had to remedy failed plasterboard fixings that others had fitted were too great to number.


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## Daniel2 (25 Jul 2021)

Misterdog said:


> Never heard them called that before, is it a French term?



I don't think so. I think they just became known as such, like
Hoover, Thermos or Elastoplast.









Molly (fastener) - Wikipedia







en.wikipedia.org


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## Jonm (25 Jul 2021)

I have an aversion to fixing to plasterboard and avoid it where possible, except for light objects. I appreciate that phloaw has been lucky and has battens behind the plasterboard where his fixings go. Where this is not the case I tend to use some 10mm steel tubing, bought specially for this.

Drill 10mm hole through plasterboard, insert tube to hit brickwork, mark and cut to length so it just protrudes beyond plasterboard, insert drill down tube (7mm works, not sure about 8mm) drill hole, put plug just on end of screw and insert plug. May need to remove screw and tap plug in place with punch (or large nail with head cut off).

I have used these where there was 50mm celotex plus air gap varying up to 30mm behind the plasterboard. Here is sketch



If the gap was small then the corefix suggested by Woody Alan look good, particularly if there were a reasonable number to do.

On my house build, the builder ensured that there was dab behind all the radiator brackets to avoid this problem.


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## Daniel2 (25 Jul 2021)

johnny said:


> forget hanging your radiator on the plasterboard or just the battens as some have suggested .
> It is not a sensible option for such a lot of weight.
> 
> Using plasterboard fixings to hang heavy items like radiators and wash hand basins should only be used as a last resort when there is not a more substantial substrate to fix to.
> ...



With respect, I have hung enough radiators to have lost count, and have yet to have any
issue with this technique. Plasterboard is, in fact, immensely strong when correct fixation
techniques are applied.
Think of upper kitchen units. Usually hung only from the plasterboard, and they too
carry far more weight than a radiator.
Probably the failures you have witnessed are due to incorrect application techniques.


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## Stevekane (25 Jul 2021)

Im sure plasterboard is incredibly strong but I personally wouldnt want to hang heavy things like radiators onto just it, esp as has been said, people do daft things like leaning on them and kids pulling themselves up on them. Screw through the battons will give you a decent fixing but, if as you have said the rad would look better sitting between the batons why not just cut the plasterboard and screw a couple of batons where you want them, finish with a wipe of polyfiller which will be hidden by both the bracket and the Rad. Its a relativly small amount of extra work but you will know that your rad is really well fixed. 
Steve.


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## Stevekane (25 Jul 2021)

Daniel2 said:


> With respect, I have hung enough radiators to have lost count, and have yet to have any
> issue with this technique. Plasterboard is, in fact, immensely strong when correct fixation
> techniques are applied.
> Think of upper kitchen units. Usually hung only from the plasterboard, and they too
> ...


Around two years ago our friends in Andover had a lovely new kitchen fitted, after a couple of days she had put a moderate amount of stuff in the cupboards and when she opened the door one morning the cupboard fell off the wall on top of her, she crashed onto the floor surrounded by broken crockery. The wall units had been fitted using plasterboard fixings by a professional kitchen fitter.
When you think about it you can make a hole in plasterboard with anything a bit pointy, and even a really course screw alone would hardly hold a picture and yet a crappy bit of folded plastic would hold a 4 or 5ft rad!! I wouldn't do it.
Steve.


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## Daniel2 (25 Jul 2021)

Stevekane said:


> Around two years ago our friends in Andover had a lovely new kitchen fitted, after a couple of days she had put a moderate amount of stuff in the cupboards and when she opened the door one morning the cupboard fell off the wall on top of her, she crashed onto the floor surrounded by broken crockery. The wall units had been fitted using plasterboard fixings by a professional kitchen fitter.
> When you think about it you can make a hole in plasterboard with anything a bit pointy, and even a really course screw alone would hardly hold a picture and yet a crappy bit of folded plastic would hold a 4 or 5ft rad!! I wouldn't do it.
> Steve.



I'm sure there will be a very good reason why the cupboard fell down.


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## johnny (25 Jul 2021)

Daniel2 said:


> With respect, I have hung enough radiators to have lost count, and have yet to have any
> issue with this technique. Plasterboard is, in fact, immensely strong when correct fixation
> techniques are applied.
> Think of upper kitchen units. Usually hung only from the plasterboard, and they too
> ...



why would you advocate fixing a 100 lb weight full of pressurised hot water to plasterboard when there is a stronger , safer fixing to brickwork available. ?


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## Daniel2 (25 Jul 2021)

johnny said:


> why would you advocate fixing a 100 lb weight full of pressurised hot water to plasterboard when there is a stronger , safer fixing available. ?



Because, executed correctly, it is perfectly safe and reliable.
It's also an issue of horses for courses. The method is simple and
straightforward. It is correctly proportionate to the task in hand.
The advice being bandied about here, is turning what is a very
simple, and basic, exercise into one of disproportionate
complexity and is unneccesarily time consuming.


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## Mal-110 (25 Jul 2021)

As Woody Alan said, I would go for the core fix. You do not know how well the battens are fixed or the plasterboard to the battens. For the extra cost of core fix against the possibility of not getting all the other holes/screws in the right place.


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## johnny (25 Jul 2021)

Daniel2 said:


> Think of upper kitchen units. *Usually hung only from the plasterboard*, and they too
> carry far more weight than a radiator.


this is not only factually incorrect it is a potentially dangerous and an unsafe practice and would never be recommended by a trained and qualified kitchen fitter.

There is no way anyone can accurately predict the amount of weight that users could put into a wall cupboard which is why manufacturers do extensive research and calculations to develop a safe product with a built in safety margin. This includes calculations of the maximum possible loading both static and dynamic.

Plasterboard fixings are never a fixing method recommended by reputable kitchen wall unit manufacturers or retailers .

No trained and qualified Kitchen Fitter would ever hang a kitchen wall cupboard on a plasterboard fixing of any kind .For one thing their professional and public indemnity insurance Policy would not cover any subsequent failure claim submitted by the customer.

If kitchen wall units are to be fitted to a kitchen stud and plasterboard wall then the units would be fixed to the studwork so that the weight and loading can be safely transferred through the studwork down to the floor.

Either a section of plasterboard would be cut out by the fitter and a noggin inserted between the studs for the wall unit to be fixed to and the small section of plasterboard would be replaced and finishes made good. The same goes for hanging radiators. Or alternatively a steel or aluminium hanging rail would be fixed to the studwork to hang the cupboards on.

A standard wall unit cupboard and door weighs approx 20Kgs and a set of plates and bowls weigh say 8kgs thats a combined load on the plasterboard of 28Kgs and the majority of plasterboard in the UK is 9.5 mm thick unless it is a firebreak wall where it would be 12.5mm
.
The posters radiator weighs nearly twice that and full of pressurised hot water. If you had ever witnessed the aftermath of an entire central heating system emptying itself onto a ground floor you might appreciate why a plasterboard fixing is neither safe nor advisable


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## phloaw (25 Jul 2021)

I think this turned into a very useful thread, at least for me: thanks everyone.
@J-G : I was amazed at the fact that you cared enough to take the time to draw.
@Jonm: this is exactly the solution I was thinking of! Due to problems in sourcing dedicated fixing such as dryline, corefix, rigifix, etc. Do you know if the 10mm steel tube is easy to find in hardware shops?


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## Doug B (25 Jul 2021)

This conversation spike my interest & made me wonder what weight a plasterboard fixing could take a quick google bought up several different makes a few of which were new to me, this P/B fixing claims 113kg per fixing more weight than I imagined









Blue


Heavy duty plasterboard anchor fixing that holds seriously heavy stuff. Easy to install and super strong. Hang domestic heating boilers, wall mounted TV's and radiators. One Gripit Blue holds up to 113kg. You will require a 25mm drill bit also available from Gripit. Each Gripit Blue is supplied...




www.gripitfixings.co.uk





They claim it is suitable for hanging boilers on a wall, interestingly I couldn’t find a weight for the Fisher toggle I tend to use.


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## phloaw (25 Jul 2021)

There is a wide choice of plasterboard fasteners, some of which can indeed stand big loads (see here for non-rigorous experiments: ).
However, the problem is long-term: vibrations, jolts, etc. can induce a progressive decay of the material, leading to final failure. This problem can be worked around with glue to prevent the slightest movement.
Disclaimer: I have no direct experience of all this, I only googled.

I would therefore avoid fastening to plasterboard if at all possible. This doesn't mean that good plasterboard securing is impossible, merely that I don't feel confident myself achieving one.


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## Rorschach (25 Jul 2021)

Cheap decorators filler or cheap no more nails type adhesive (not decorators caulk, you want stuff that sets pretty hard, you can also mix your own powder filler and put in an old mastic tube) in a mastic gun is great for preventing plasterboard from collapsing if you only have a shallow cavity, drill your hole, squirt in a good splodge of the filler/adhesive and let it set overnight. You now have a pretty solid bridge between the plasterboard and the wall behind. As long as you are fitting something with a washer/bracket that spreads the load the plasterboard now won't collapse.

This trick works well for fixing the same issue caused by someone else.


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## Misterdog (25 Jul 2021)

Stevekane said:


> a crappy bit of folded plastic



Only expanding metal fastners designed for the job and load tested have been suggested though,


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## hunter27 (25 Jul 2021)

Was an heating engineer for 42 years and no way would I try to fix a rad through plasterboard into a 1/2" batten if there was bricks behind it, have had to repair plenty of rads that have been fitted with toggle screws in plasterboard and thermolite blocks aren't much better behind dry lining especially in kids bedrooms. I wonder why all/most radiators are supplied with plugs and long screws and not plasterboard fixings and glue


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## phloaw (25 Jul 2021)

hunter27 said:


> Was an heating engineer for 42 years and no way would I try to fix a rad through plasterboard into a 1/2" batten if there was bricks behind it, have had to repair plenty of rads that have been fitted with toggle screws in plasterboard and thermolite blocks aren't much better behind dry lining especially in kids bedrooms. I wonder why all/most radiators are supplied with plugs and long screws and not plasterboard fixings and glue


Not sure: do you mean the way to go is to fasten to bricks?


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## Spectric (25 Jul 2021)

You can get these issues with dot and dab plasterboard, my solution has been to drill a 6mm hole through the pboard into the massonary. Then using a hole saw centred on yur hole cut out the pboard to leave a void, now drill out the 6mm hole to suit the nylon fischer plug and fit plug. Need a round section of wood with a hole in it that fits the hole and sits flush, now you can screw straight into the plug and no compression of pboard or extraction of plug that can blow out face of certain types masonary.


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## hunter27 (25 Jul 2021)

phloaw said:


> Not sure: do you mean the way to go is to fasten to bricks?


Through batten to stop pulling plasterboard in and into brick behind then long screws. I could have fitted a full c/h system in the time this we are still discussing screwing a couple of rad brackets on


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## Rob_Mc (26 Jul 2021)

There are specific products designed for fixing into brickwork and bridging the cavity between plasterboard and wall in high load situations. They are designed to ensure you don't deflect the plasterboard when tightening the fixing. For example Rigifix;






Rigifix M8 Anchor Fixings 4 Pack : Amazon.co.uk: DIY & Tools


Shop Rigifix M8 Anchor Fixings 4 Pack. Free delivery on eligible orders of £20 or more.



www.amazon.co.uk





I have used these and they work brilliantly. You drill a hole in the wall through to the brickwork, insert the plastic sleeve, screw the long metal insert into the plastic sleeve with an allen key. This leaves the metal insert flush with the plasterboard and fully supported by the brickwork, so when you tighten you radiator bracket up against it (with the provided M8 screw) the plasterboard can't deflect in over.

Here is a video showing the principle;



I use mainly the M8 version but a smaller M6 version is available. You need to drill a 16mm hole (100mm long) for the M8 sleeve.





Here is the datasheet with the specifications and load bearing capacity;



http://buyrigifixonline.co.uk/wp-content/uploads/2018/03/Rigifix_Main_Datasheet-DELTALEIGH.pdf


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## Jonm (26 Jul 2021)

phloaw said:


> I think this turned into a very useful thread, at least for me: thanks everyone.
> @J-G : I was amazed at the fact that you cared enough to take the time to draw.
> @Jonm: this is exactly the solution I was thinking of! Due to problems in sourcing dedicated fixing such as dryline, corefix, rigifix, etc. Do you know if the 10mm steel tube is easy to find in hardware shops?


The problem I had was hanging kitchen wall cupboards on a 9 inch wall which had been lined with 50mm celotex and plasterboard, no studs, the plasterboard was fixed back to the wall with long plasterboard screws. In places there was a gap between the celotex and the wall, foam filled. Advantage was that there were no cold spots.

I bought the steel tube from a local steel supplier. The closest one only sold it in 6 metre lengths but I reasoned that it would come in useful for other things, and it has. I had a quick look online and there are steel places that sell shorter lengths. When I come across this problem I tend to use this method as I have the tube available.

If you only have a 12 mm gap then Rorschach method should be fine, provided you have time to wait for it to set. As he said, you need the cheap stuff that sets solid.



Rorschach said:


> Cheap decorators filler or cheap no more nails type adhesive (not decorators caulk, you want stuff that sets pretty hard, you can also mix your own powder filler and put in an old mastic tube) in a mastic gun is great for preventing plasterboard from collapsing if you only have a shallow cavity, drill your hole, squirt in a good splodge of the filler/adhesive and let it set overnight. You now have a pretty solid bridge between the plasterboard and the wall behind. As long as you are fitting something with a washer/bracket that spreads the load the plasterboard now won't collapse.
> 
> This trick works well for fixing the same issue caused by someone else.


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## baldkev (26 Jul 2021)

Hold my beer...... 

Im not going to weigh in on the p.b fixing debate, but i would mark out the section of wall where the rad is going, including bracket height, cut out the p.b behind the rad and stick a lump of ply in.
This way you get to check and if necessary, reinforce the batten fixings ( 12mm studs?? ) before you install the ply. You can use 15mm ply, fill as necessary ( hidden behind rad, but scrim tape and easifill would be nice ) paint it wall colour, hang brackets and rad.... at least you can use 5x30 screws into the ply


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## Stevekane (27 Jul 2021)

Misterdog said:


> Only expanding metal fastners designed for the job and load tested have been suggested though,


Artistic licence old fruit,,,but you get the point and our chum the heating engineer confirms what I suspect most people would think, hanging a rad onto just plasterboard with any type of fixing is chancy to say the least.


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## johnny (27 Jul 2021)

hunter27 said:


> Through batten to stop pulling plasterboard in and into brick behind then long screws. I could have fitted a full c/h system in the time this we are still discussing screwing a couple of rad brackets on


that made me laugh Hunter........  sometimes you just want to say '...oh for heavens sake just give it to me and I'll do it for you ' lol


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## Daniel2 (27 Jul 2021)

Right, but that's not really in the spirit of the forum is it ?


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## johnny (28 Jul 2021)

...lighten up Daniel.... we cannot expect everyone to always agree with us about everything can we eh !
A Forum is a place for meeting and open discussion


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