Plywood Ceiling And Downlights

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safedepth

safedepth

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Evening all,

Please bear with me here!

Can anyone offer some advice regarding the installation of downlights in a wooden ceiling. 

A customer has had a bespoke summer house installed, I was tasked with providing the electrics which I attended to install today. On arrival it transpired that the summerhouse came pre wired. It is built at the factory, dismantled, transported to site then re assembled.

The installers were there today to complete the snagging list. They informed me it was all ready for test once I had connected, when I asked for the design and installation certificate they went very quiet.

Following some testing I found many many faults, not least of which on the lights.

No earth continuity from switch to fittings, Class 3 fittings with GU10 lampholders and halogen 50w lamps. Fittings butted right up next to the wooden ceiling joists and the ceiling itself is 10mm foil backed plywood with a skimmed and painted internal finish. 8 lights inside and 5 more outside in the eave. None are suitable for outdoor use.

I've told them and the customer the electrical design and install quality is carp. They informed me they did all of there own electrical work, design onwards. All without the aid of an electrician.

Indeed the big bloke who actually did the wiring asked "How come the lights are working if there is no earth then?" in a smug kind of way!!!

What I can't find in the BGB is a definitive statement concerning ceiling material and fire safety. Ceiling void depth is 70mm max, very little room for fittings to breathe.

I've informed them the current positions are a no no.

Manufacturer's instructions aside, would anyone allow the fitting of a downlight in a wooden ceiling?

Cheers.

 
most downlights have 2 ratings, usually 50w in non-flammable ceiling, 35w in flammable ceiling. so yes, they can usually go direct into wood (same with plastic ceilings etc).

as for space behind it, 7671 says to follow manufacturers instructions, which will state depth required

also, you cant get a class III GU10. its either class III MR16 or class II GU10

 
Last edited by a moderator:
I wouldnt have a problem with them being in a wooden ceiling,, in fact I fitted some recently in a plastic ceiling.... They were F (in upside down triangle - meaning they are suitable for installation on/in a normally combustable surface) and they did also have 5W LED lamps fitted.

 
Some halogen lamps are not good on ceilings have seen them leave scorch marks on plasterboard ceilings even damage the ceiling so on plywood possibly could cause a fire.

 
Thanks all,

In order,

Andy.

I must admit, I've never noticed two ratings on a fitting as you suggest. Also, it's a class III fitting (as labelled on it) but they've exchanged the MR16 lamp holder for a GU10.

M107, I'll try to get a copy of that.

ProDave

Do they generate that much less? I've not really investigated but the massive heats sinks would indicate that still do.

Noz,

These aren't labelled as such but I can search for suitably sized items that are.

Paddler,

I'll read them later, thanks.

Batty,

My thoughts too.

 
safedepth said:
ProDave

Do they generate that much less? I've not really investigated but the massive heats sinks would indicate that still do.
Click to expand...
the heatsink is purely to dissipate the heat easier, keeping it cooler. they do get warm, but even after an hour they are still cool enough to touch. after a few seconds you will burn yourself touching a GU10

 
safedepth said:
Evening all,

Please bear with me here!

Can anyone offer some advice regarding the installation of downlights in a wooden ceiling. 

A customer has had a bespoke summer house installed, I was tasked with providing the electrics which I attended to install today. On arrival it transpired that the summerhouse came pre wired. It is built at the factory, dismantled, transported to site then re assembled.

The installers were there today to complete the snagging list. They informed me it was all ready for test once I had connected, when I asked for the design and installation certificate they went very quiet.

Following some testing I found many many faults, not least of which on the lights.

No earth continuity from switch to fittings, Class 3 fittings with GU10 lampholders and halogen 50w lamps. Fittings butted right up next to the wooden ceiling joists and the ceiling itself is 10mm foil backed plywood with a skimmed and painted internal finish. 8 lights inside and 5 more outside in the eave. None are suitable for outdoor use.

I've told them and the customer the electrical design and install quality is carp. They informed me they did all of there own electrical work, design onwards. All without the aid of an electrician.

Indeed the big bloke who actually did the wiring asked "How come the lights are working if there is no earth then?" in a smug kind of way!!!

What I can't find in the BGB is a definitive statement concerning ceiling material and fire safety. Ceiling void depth is 70mm max, very little room for fittings to breathe.

I've informed them the current positions are a no no.

Manufacturer's instructions aside, would anyone allow the fitting of a downlight in a wooden ceiling?

Cheers.
Click to expand...
I also need advice on it, Want to do my ceiling with laminated floorboards tongue and groove no nails concerns glue heat durability's ?

 
s.pathak said:
I also need advice on it, Want to do my ceiling with laminated floorboards tongue and groove no nails concerns glue heat durability's ?
Click to expand...
Use LED GU10.  . Both laminate and wooden flooring  expands and contracts in the hot and cold  so i doubt it would be suitable for your idea.  There is probably  a better adhesive that allows movement for what you want to do if you must.

 
That fitting near the joist , M.I,s usually say 40mm distance  but as said above , LED lamps would solve all that .  

However , by the sound of it , they have no right to be doing their own electrics.

 
Evans Electric said:
That fitting near the joist , M.I,s usually say 40mm distance but as said above , LED lamps would solve all that .

However , by the sound of it , they have no right to be doing their own electrics.
Click to expand...
This post, from two years ago, was dragged back out by someone who was not bothered enough to start his own.

I informed the customer of my concerns and advised that he instruct the makers to redo the electrics. I don't think he did though.

Their product looked far better than the testing showed it to be.

In the end I believe I supplied a cert for my new supply but limited it to that only and excluded the summer house install.

 

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