Fire proof spot lights

[88daveb]

Myself and a mate have some spot lights to install in a rough 5m^2 room. 25 spots in total, 5 rows of 5.

The joists which hold the plasterboard in place for the ceiling, which will soon be skimmed, now the joiner has gone across the room with long joists and then offset each joist the other way, if you understand me so far..

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like so.

the ceiling needs to be fireproof, hence the new ceiling, but the old one is still 3ft above. now we have measured out where the spot lights are going, and have predicted that we will hit two joists. now the way the joiner has made the new ceiling, thats the minimal amount we hit, with regards to the spot lights all being in line with each other. so what are the recommendations, and is the 50mm from joists only from the joists supporting the stucture?

im unsure and thought i'd ask, can we use something nonflammable to coat the joists, etc?

 

[Lurch]

When you say hit the joists, you mean as in plumb in the middle hit, or tight up against hit?

What lights are you fitting?

 

[88daveb]

we are fitting 50W spots fire proof, we will be hitting about less then a quarter of the joist part.

 

[PC Electrics]

What do you mean by "fire proof spot lights"?

I believe there is no such thing. There are "fire rated" spotlights. These contain intumescent material which prevents the passage of fire across the ceiling, thus retaining the fire rating of the ceiling, esp if it's a 1 or 1 1/2 hour ceiling.

What is the fire rating of this ceiling you are installing into? Again, no such thing as "fire proof".

I believe that most manufacturers instructions are quite clear: downlighters should be installed with a minimum of 50mm clearance from the edge of the lamp to any combustible material (eg joist or noggins).

Also vital is that almost all downlights must have sufficient ventilation behind to allow heat dissipation.

You can find an excellent article on recessed luminaire installation in the downloads section, but here's a link:

http://www.talk.electricianforum.co.uk/downloads.php?do=file&id=89

I'm sure you don't want your installation to become a statistic:

http://www.esc.org.uk/business-and-community/research/luminaires.html

Note also, that improperly installed luminaires that can be considered a fire risk could well attract a '2' rating on any future PIR of the building, generating an unsatisfactory report:

http://esc.org.uk/pdfs/business-and-community/electrical-industry/BPG4_08.pdf

 

[tom1]

i am not following this joist lay out you describe,

the joist he has put in these hold up the floor above yes

and the off set ones are these noggings between the joist?

when i fit downlights they get the clearance stated in the instructions,

 

[M107]

If they are just noggins knock them out the way.

Anybody used the new Aurora DL' & trannys that can be covered with insulation?

 

[88daveb]

these joists do not hold up the floor above and he has put noggins inbetween the joists. ..so is it okay to knock the noggins out of the way? Is it ok to cut these out at all to get the 50mm away from the spot lights.

Yes they are fire rated. sorry about the confusion.

 

[binky]

You could always use low energy lamps thereby reducing fire risk, with 25 spots burning leccy @1.25KW, customer will have one hell of bill. You could also check fitting for an F in a triangle which gives a lamp rating for fitting to flammable material surface, and I think will allow you to mount closer to wood joists.

Although the official gap is 50mm, having seen lamps cut into joists on many occassions without so much a shinge to wood, I work on the basis that about 10mm is probably OK in most circumstances - that is not official of course

Question, is the builder fitting insulation to void.

 

[tom1]

could you knock them out then and move them

or just knock them out

 

[a1spark]

There is no compromise to be had here on safety.

option 1. Ceiling suppost timbers to be located.

option 2. light fittings to be re-located

--the rest is down to you 88. mate

a1spark.

 

[88daveb]

i've had a word with the joiner and he says im ok to knock the noggins out for these two spot lights. and he'll set them in again.

These spot lights have a type F on them.

The building will be inspected by the council on completion. I'd rather be 100% sure, than have plenty of doubt.

The owner has 60 spot lights in his kitchen, and he said the room above feels like a sauna!. his kitchen is rather big too.

Thanks for the help lads,

Much appreciated.

 

[~Sparky~]

60 SPOT LIGHTS IN HIS KITCHEN!!!!!!!..... no wonder the room above feels like a sauna......... i wonder if they are all on the same circuit lol

 

[88daveb]

haha, no, they are on 4 different ccts, so he's gt 4 different switches.

 

[~Sparky~]

thats handy, he can then have the above room at different temp's as well if he wanted,,, lol

 

[Badger]

i have 61 just in the bedroom :^O :^O :^O oh and not forgetting the glass cabinet spots too :run

 

[a1spark]

thats handy, he can then have the above room at different temp's as well if he wanted,,, lol

ROTFWL

a1spark

 

[Andy™]

could you knock them out then and move them or just knock them out

they are there for a reason. and that reason isnt to be removed so downlights will fit.

 

[binky]

haha, no, they are on 4 different ccts, so he's gt 4 different switches.

Yeah but, fed from how many circuits at CU?? No doubt in 1mm and through rockwool

 

[Badger]

Yeah but, fed from how many circuits at CU?? No doubt in 1mm and through rockwool

it comes from the main fuse :^O :^O :^O ] ] :slap :slap :Spam2 :Spam2 :| :| :coat :coat :run :run

 

[anwah]

If 60 gu10`s were installed he will need about 100 spare lamps that should keep him going till about christmas.