Fitting rads to 50mm thick insulation boards.

[cr0ft]

Hi all. Been asked to fit some rads in a very old stone walled house. The plasterer has fitted 50mm insulation boards to the stone walls then dot and dabbed plasterboard on top. There is virtually no gap between the plasterboards and insulation boards.

My question is - how the hell do I fit the rads to these walls now? I am sure there must be a suitable fixing but there is no room between the plasterboard and insulation board to use a spring toggle. Lightweight helix screws will be no good.

Even 100mm drywall plugs are only going to get 38mm or so maximum into the stone wall, that is of course assuming I can actually drill into the stone wall with any degree of accuracy with a 60mm soft material gap in front of it.

What the hell do I do to hang them lol.

 

[hammers4spanner]

Cut the board out and fit patrice board

 

[Ermintrude]

200mm torx concrete screws. I would be putting a large bit of 6mm ply behind brackets or some 22mm as a spacer between stone and rads to

(Yes I had one in my living room)

 

[galaxy_plumbing]

floor standing?

 

[AWheating]

Very long screws as per ermi.

 

[iiplumbing]

Cut vertical slots in plaster and insulating board right where the brackets will be fitted

Insert the correct thickness of timber baton

Pick up the mortar lines and drill there for your fixings (3 off brown plug No 10 screw)

Fix rad brackets to batons

Hope this helps

If there are no mortar lines don't know what to suggest!

Russ

 

[Nostrum]

Umbrella fixings?

 

[Mike Jackson]

I use 6" frame fixings

 

[mfgs]

I have had this a few times. The best solution is to cut the board and fit some timber to the wall. I have also drilled and fixed 12mm stud into the wall and then drilled out the rad bracket.

 

[albatross]

CAVITY WALL ANCHOR SETTING TOOL GUN & 100 CAVITY FIXINGS 5 X 45 FOR HOLLOW WALLS | eBay

something like this

 

[Leo21]

View attachment 17981
CAVITY WALL ANCHOR SETTING TOOL GUN & 100 CAVITY FIXINGS 5 X 45 FOR HOLLOW WALLS | eBay

something like this

If the rads are big I wouldn't use these, not enough spread. Long screws with some 22mm copper tube as sleeves to stop the bracket pulling into the plasterboard.

 

[tom609]

cut out where the screw fixings are going approx 3-4 inch sq scrape out some insulation 1inch all round then plaster up i usually use 2 bonding and 1 cement mix goues off in about 20mins use this process on paramount or dry lined works a treat

 

[kay-jay]

How big are the rads? If not too heavy I just use rawlplug uno plugs and silicone the brackets down the back. Let it go off and hang the rad. It wont shift

 

[cr0ft]

Hi all. They are all single rads. Largest one is 600 high by 2000 wide. Some of them are pretty big single rads.

I was thinking of getting some 2x2 timber, cutting out slots with my Fein cutter where the brackets are going to go. Gripfill the stone wall in the slots, push fit in the timber flush to the board surface ensuring enough gripfill to reach the stone wall. Let it dry then hang the rads with screws.

What do you reckon?

 

[cr0ft]

How big are the rads? If not too heavy I just use rawlplug uno plugs and silicone the brackets down the back. Let it go off and hang the rad. It wont shift

10-12mm Fischer plugs with the lips on the front and the ridges on the side should do the job I reckon, especially if the brackets are siliconed on too.

 

[Killy Bing]

Drill into the stone and use chemical anchors for the wood, gripfill the back of the wood too, then screw mdf sections to give a flush finish the the plasterboard and screw through these for the brackets

i wouldn't rely on gripfill alone tbh

 

[Ermintrude]

Hi all. They are all single rads. Largest one is 600 high by 2000 wide. Some of them are pretty big single rads.

I was thinking of getting some 2x2 timber, cutting out slots with my Fein cutter where the brackets are going to go. Gripfill the stone wall in the slots, push fit in the timber flush to the board surface ensuring enough gripfill to reach the stone wall. Let it dry then hang the rads with screws.

What do you reckon?

Stone sweats and rads fall off. Needs a mechanical fix!

 

[kay-jay]

10-12mm Fischer plugs with the lips on the front and the ridges on the side should do the job I reckon, especially if the brackets are siliconed on too.

not sure which fischer plugs you mean, but the uno ones are designed to be a universal plug for all wall types even plasterboard. use these and you will never use a toggle fastener or a pig tail again.
Rawlplug Uno Brown Wall Plug Pk 300 | Plastic Wall Plugs | NoLinkingToThis

 

[cr0ft]

not sure which fischer plugs you mean, but the uno ones are designed to be a universal plug for all wall types even plasterboard. use these and you will never use a toggle fastener or a pig tail again.
Rawlplug Uno Brown Wall Plug Pk 300 | Plastic Wall Plugs | NoLinkingToThis

The Fischer ones are basically even more beefed up versions of them. That front lip and the prongs are the most important bit I think. They are so much better than normal rawl plugs in fact they are all I use!
After much thought I am going to fit Fischer 12mm plugs in the plasterboard/insulation and also silicon on the brackets to the plasterboard prior to skimming.

I reckon that will do the job nicely.

Cheers to all for help.