Heavy Radiator

Good idea, as long as it doesn't push the plasterboard away from the blockwork as it would probably 'cure' faster than Gripfill.

Cheers, T i m

And the plasterboard?

Bill

READ: anything

when I look at the fixings

Everyone does, don't they? Maybe not...

Bill

Surely the screws themselves aren't the issue. The breaking strain of even 5mm screws is probably a significant fraction of a tonne. A quick calculation suggests it is approximately 10000 Newtons, which is actually quite close to 1 tonne.

So four 5mm screws strikes me as quite sufficient in themselves, the issue is whether the wall is hard enough to hold them tight.

No hope of shedding some load on the floor via some kind of block I suppose? Brian

No. But I'd not dream of fixing one to plasterboard.

Mostly things are supplied with No6 or No8 x 1" or 1½" woodscrews. That encourages people to use red or brown plugs. A lot of people abandon their own common sense and think, "Well, if these screws are supplied they must be alright." Yes they would be if screwed into sound timber.

Sometimes No10 screws are supplied, but often they are too short.

The other thing is, often the screwheads don't work well with either slothead or posi.

When using plastic plugs I think it's always worth going to a bit of extra trouble and using blue plugs in a 10mm hole, with No10 screws of adequate length. It's surprising how much stronger a blue plug fixing is than a brown one. And red ones are s**te for anything.

Bill

Agreed. People do grab radiators when they think they're falling. Also old people sometimes hold the radiator to stabilise themselves when reaching behind the telly to grasp and pull the aerial plug out of the telly because there's lightning outside... It's sort of electrical Covid.

Bill

It's about security and stability, not just just dead weight. You can't have a seven foot high rad full of water falling on somebody.

Bill

Those red plugs do actually have two practical uses....

I have UPVC windows here and I don't like putting roller blind screws into the plastic frame as its impossible to make good when replacing blind with a new blind.

I actually drill 6mm diameter holes into the window plasterboard reveals and stick red plugs in the holes.

They are short enough for the PB but there is no point in trying to use

The red plugs will then hold the screws (screwing directly into PB does not work at all)

I then drill holes ine the roller blind brackets so it will then allow me to fix them to the window reveal PB and as long as one cuts the roller blind accurately, its actually hard to pull the whole roller blind down to the point of the fixings coming loose.

Another use isin first fixing electrics.....

When first fixing cables to masonry walls with capping...... Those masonry nails into proper bricks are either too hard to hammer in or bend or do not hold well in thermalite/breeze block and they loosen...

I hold capping against wall, uss a 6mm masonry drill bit, drill through capping edge and into wall. fit red plugs, use a screw and washer and affix capping to wall into those red plugs and then plaster over.

I'm paranoid about wall fixings. Dates from when I fitted some wall cupboards in the kitchen using the supplied screws (into plaster over brick) and on filling them with crockery and tins, etc, came down. Causing expensive damage.

Generally if a fixing looks inadequate, it usually is. And the vast majority are, as supplied.

I find Everflex Premium 165 Small Gap Filler is good for plugging holes like that in PVC, it's a weld/adhesive rather than a silicone/sealer, so when it dries you can cut it flush with a chisel or filling knife.

Or even an empty seven foot high rad falling on someone, like the kid who tried to swing on a big mirror in a shop somewhere, which promptly fell on him and killed him.

The longer the cantilever, the bigger the washers need to be. The bending moment puts a crushing force on the brick at the bottom and outside of the hole. Hence my suggestion of using plywood "washers" two or three inches in diameter. Putting these in compression with the screw or bolt gives you a vertical frictional joint which takes up the shear loads from the heavy radiator, removing that bending moment in the shank of the fastener.

williamwright formulated on Thursday :

I still wouldn't fix such a heavy item to plaster board.

I would drill a hole through the PB, the same size as the back of the bracket, then make up some sort of spacer the same depth as the face of the PB to the breeze, then fix firmly through that spacer using long screws/ even bolts.

I have seen far too many radiators rip PB off, especially dodgy with a tall radiator which can fall a long way.

newshound laid this down on his screen :

Spacers can be made from bits of small diameter copper pipe.

Bill

williamwright explained :

True, but I would expect them to simply crush when the fixing are tightened for this.

Drill through the plaster board and get some adhesive type fixings if you are really worried but any decent long fixing for breeze block will probably be ok. In a place I replaced a rad in someone had sunk wooden blocks in the wall and used coach screws. They were solid as a rock.