Any problems fitting bathroom downlights in UPVC cladding

[Vogon64]

I am refitting my bathroom and intend to clad my ceiling in UPVC shiplap cladding. I want to fit some IP65 Shower rated downlights (5), ideally LV ones with a separate transformer that I can mount in the loft space out of the way.

Is there likely to be any problem with heat build up damaging the cladding?

As the rear of the units will be penetrating into the roof space, is it necessary to have clear "airspace" around the back for ventilation?

Do I need to pu anything over the back of them to keep the fibreglass insulation away from them.

Any recommendations of suitable units (I want fixed white finish probably).

thanks in advance.

 

[1john]

plenty of ventilation required and insulation distance from the fitting will depend on the manufacturer.

Do you know about 'Part P' ??
Is the current lighting circuit fed from an RCD or RCBO
Are there any other circuits feeding the bathroom?
Are they RCD protected
Do you have supplementary equipotential bonding in place?

I have seen downlighters mounted in PVC that has melted it, i have seen them mounted in PVC and it is fine.

To be certain of not scorching the PVC have you considered CFL or LED lamps?? (these are mains voltage not ELV)

 

[ban-all-sheds]

I am refitting my bathroom and intend to clad my ceiling in UPVC shiplap cladding. I want to fit some IP65 Shower rated downlights (5),

5.

And the combined wattage of those compared to what you'd need if you didn't try to light the room with 2" diameter recessed torches is...?

Does that tell you anything about how well they work, in terms of ability to provide room illumination?

ideally LV ones with a separate transformer that I can mount in the loft space out of the way.

The IEC definitions of voltage bands are:

• Extra Low Voltage: AC below 50V and DC below 120V
• Low Voltage: 50 - 1000V AC or 120 - 1500V DC
• Medium voltage: 1kV - 35kV
• High voltage: 35kV - 230kV
• Extra-high voltage: >230kV

This is not some pedantic technical point - if you start getting involved in doing your own electrical work, and start learning about regulations etc you'll come across references to "Low voltage", and it'll be no good you thinking that that means 12V...

Is there likely to be any problem with heat build up damaging the cladding?

//www.diynot.com/forums/viewtopic.php?t=215695

As the rear of the units will be penetrating into the roof space, is it necessary to have clear "airspace" around the back for ventilation?

Yes, the instructions should tell you how much.

Do I need to pu anything over the back of them to keep the fibreglass insulation away from them.

Yes, you need a sealed enclosure providing the clearance the manufacturers specify.

It must be sealed, and sealed against the ceiling, to prevent moist air from the bathroom getting into the loft and causing a problem with condensation. This is a requirement of Part C of the Building Regulations.

You must also reinstate all of the insulation, which will probably mean getting more of it, as the humps will need longer pieces to cover them. You have to keep the insulation levels the same as before or you'll be in contravention of Part L of the Building Regulations.

Finally, adding these lights is notifiable - see //www.diynot.com/wiki/electrics:part-p

Any recommendations of suitable units (I want fixed white finish probably).

Anything except small recessed lights.

 

[flameport]

I am refitting my bathroom and intend to clad my ceiling in UPVC shiplap cladding.

A huge mistake.

Downlighters can't be fitted, as they will melt the cladding.
You could use LED lights, but they would have to be the very expensive ones which only accept LED lamps, to prevent someone fitting a halogen lamp at a later date.

Unless the cladding is completely sealed (almost certainly impossible), moisture will get behind it and make the original ceiling go mouldy. By the time the mould has spread enough to show, it will be so bad that the whole lot will have to be ripped down and completely replaced.

 

[Vogon64]

BAS, thanks for link to plastic ceiling nightmare!

That and other comment about mould is making me rethink.... I was awaer of regs and notification etc, but had not thought the ceilng would be such a problem.

Like many poeple my loft is full of C**p and so don't really want to have "protrusions into the loft space. The thought of condensation problems in the loft are also putting me off making holes in the ceiling!

Perhaps I will just get a surface mounted fluorescent or some spots where the current ceiling light is fitted rather than messing around with flush ceiling lights.

This thread is probably now in the wrong place, but what would people suggest for the ceiling....

I have moved some partition walls to extend the shower cubicle and as a result the ceiling is a mess, liked the idea of a few battens and then some cladding to tidy it all up.

Surely comments on condensation and mould would apply equally to wooden cladding, or would insulation behind plastic (or wood) sort out the problem. If both are nonsense then suggestions as to what I shoul do are gratefully received.

 

[flameport]

Any cladding will have the issue of moisture being trapped behind it.

If the ceiling is damaged, fix plasterboard over whatever is there and have it skimmed over. Probably cheaper than plastic cladding, the result will be much better and it will certainly last longer.

Some lighting alternatives:
http://www.google.co.uk/products?q=bathroom+lighting&hl=en&show=li&lnk=showgrid

You can probably do away with a grotty pull cord for the switch - wall mounted switches are acceptable in the majority of bathrooms.