Hanging chandelier

[george121212]

Thanks for the replies , the new light is the one still packaged. What you cannot see is the glass decor which hasn't been hanged on it yet as per picture which adds extra weight. 9kg is probs a slight overestimate as I am shortening the chain so likely 7-8kg but going to prepare for extra weight.

Thanks for the post above regarding beam supports. I thought two x long no 5 wood screws 80mm or so would be suffice? Plaster is 12mm thick.?

 

[Sureitsoff?]

Use large penny washer to help stop the metal bracket bending. "every little helps.."

 

[JohnW2]

Thanks for the post above regarding beam supports. I thought two x long no 5 wood screws 80mm or so would be suffice? Plaster is 12mm thick.?

Do you really mean "No. 5" ? I'm not suree that I've ever seen such an animal, but it would be somewhere between No. 4 (~3.0mm) and No. 6 (~3.5mm). I would personally not use a screw smaller than No. 8, and would probbaly be inclined to use No. 10 (~5 mm).

Did you perhaps mean 5mm (roughly No. 10) ?

I would say that 80mm long would be overkill, and probably would be happy with 50mm or thereabouts.

Kind Regards, John

 

[JohnW2]

I used this View attachment 303189 which is seems has been discontinued, with the hook taking the weight I was not that worried, but to hang on the power cord yes I think 5 kg is a bit much ...

As I've said and illustrated in the past, I have a lot of those (in brass) in my house, including some mounted 'vertically' on walls, rather than 'horizontally' on ceilings, to support high uplighters (see pic below).

However, as I recently wrote, no matter how able the rose is to support a particular weight, the quality/.safety of the support will be totally dependent on how well the the 'rose' itself is attached to the ceiling/whatever - which, as I said, takes one back to the OP's issue/question.

Kind Regards, John

 

[george121212]

Thanks you John yes sorry meant a 5x50mm screw. Will let you know how I get on. Thanks for the help

Do you really mean "No. 5" ? I'm not suree that I've ever seen such an animal, but it would be somewhere between No. 4 (~3.0mm) and No. 6 (~3.5mm). I would personally not use a screw smaller than No. 8, and would probbaly be inclined to use No. 10 (~5 mm).

Did you perhaps mean 5mm (roughly No. 10) ?

I would say that 80mm long would be overkill, and probably would be happy with 50mm or thereabouts.

Kind Regards, John

 

[JohnW2]

Thanks you John yes sorry meant a 5x50mm screw. Will let you know how I get on.

As I suspected

Kind Regards, John

 

[ericmark]

I looked for the weight a wood screw can hold, one can find the shear strength, but not what is held on the threads, I see screws being used at work with impact drivers and clearly these can hold more than one fitted using a hand cranked screwdriver, so likely there is no fixed weight they can hold, the only way is to test, I note

In places where the fixing means is intended to support a pendant luminaire. the fixing means shall be capable of carrying a mass of not less than 5 kg. If the mass of the luminaire is greater than 5 kg, the installer shall ensure that the fixing means is capable of supporting the mass of the pendant luminaire.

should an EICR include testing the weight a ceiling rose will hold, I think it would result in a lot of ceiling repairs? I have seen ceiling roses held by the plaster board, I think 5 kg would be asking a lot with some ceiling roses?

 

[JohnW2]

I looked for the weight a wood screw can hold, one can find the shear strength, but not what is held on the threads,

Indeed, as you imply the strngth of a screw is iurrelevant. It's the 'strength' of the connection between the screw and the wood (or whatever) that matters - and that depends upon so many factors that one could not hope for anything but the vaguest of indications of how much force it would take to 'pull out' any particular screw.

I see screws being used at work with impact drivers and clearly these can hold more than one fitted using a hand cranked screwdriver, ...

The amount of force required to 'pull out' a screw (or bolt) has got virtually nothing to do with the force used to 'screw it in' Think of a large bolt - even if only 'hand tight' it would require an extremely large force to 'pull it out'. Tightening fixings to specified torques is all about avoiding the risk of them 'unscrewing' (e.g. due to vibration), and has little/no bearing on how much force is needed to 'pull it out' (by shearing the threads).

.... should an EICR include testing the weight a ceiling rose will hold,

EICRs are all about electrical safety, so I would suggest that the short answer is probably 'no'. In any event, to the best of my knowledge there are no regulations in BS7671 (which is what EICRs are based upon) about the weight-carrying capacity of ceiling roses (the nearest being tabulated 'guidance' in an 'informative' Appendix) - so an EICR could probably not claim that there was non-compliance with any regulation, anyway.

Kind Regards, John

 

[bernardgreen]

I see screws being used at work with impact drivers and clearly these can hold more than one fitted using a hand cranked screwdriver

I would not agree with that. An impact driver could strip the "thread" the the screw has cut into the timber

 

[george121212]

Hi just to update , moved some floorboards above and below the joists are Battons holding the plaster board up. I would have ended up supporting the new light via the Battons rather then the joists so glad to have checked.

To support the light thinking of using 2 of these 150mm hangers between the 2 joists, some timber in-between and then screwing the 9kg light into the timber between the hangers.

Buy Simpson SAE Hangers | SAEL500/150 Heavy Duty Face Fix Hanger 150mm

The Simpson SAEL hanger is a heavy-duty hanger designed for applications requiring additional strength. The SAEL hanger can be installed a variety of header members including timber, steel, masonry & I-Joists. The SAEL hanger can be nailed using square twist nails, and it also has bolt holes for...

www.tcfixings.co.uk

Would be great to get thoughts. Thanks

 

[chivers67]

That should do the job, I'd put a maintenance free junction box in there and just drop a single T&E down to the light to make it easier to terminate and less flaff.

 

[george121212]

Thanks Chivers,

Trying to think what bit of 150mm x150mm timber to put in. It would only be a short stretch between the joists. Any recommendations for what timber to use?
Also is it worth bolting the hanger through the joist , by drilling a small hole or would some simple wood screws be suffice?

Thank you

 

[JohnW2]

Thanks Chivers,

Trying to think what bit of 150mm x150mm timber to put in.

Do you really mean 150mm x 150mm? That's enormous, and not all that smaller than the beam holding up two stories of part of my house.

It would only be a short stretch between the joists. Any recommendations for what timber to use?

What you propose would obviously 'work, but represents serious overkill. A piece of small timber (say about 50mm x 25mm) of any type, attached simply to the joists (just screwed or nailed or using small angle brackets) would be more than enough to support your 9 kg fitting.

Kind Regards, John

 

[flameport]

You are massively overthinking this.
Get 2 woodscrews and screw the bracket into the piece of timber that's already there.

The whole thing will be held up by these two tiny machine screws into the flimsy metal dish.

what bit of 150mm x150mm timber to put in

 

[chivers67]

I think the thinking is 150 to go into the size of that hanger, doesn't need to be more than 50x50, in fact you could get a smaller hanger . 50mm perhaps?

Though Flameport's right unless the existing joist isn't in the existing correct place.