Luminaires fixed to flammable surface


I’m am here installing some Ansell led vapourproof fittings shortly. These particular fittings come with a metal clip that fixes to whatever surface you are attaching them to and then the actual fitting clips onto this clip. I intend to fix the mounting clips to a wooden surface but am wondering about heat from the fitting affecting the wooden surface. Obviously the metal clip sets the fitting off the wooden surface by 20mm or so so it is not in direct contact with it. Their technical support said that it should be ok to install like this but I must admit I wasn’t filled with much confidence. There are no markings on the fitting or on their website stating if it is suitable to install on a flammable surface. I don’t want to suspend them on chain as I want to loop in/loop out with conduit and singles. 
what way are others in this group installing these type of fittings?

thanks in advance


  • How hot do you think these fittings get ?

    LED fittings are normally quite efficient and do not run much hotter than blood-heat usually. If you have one to hand just run it up on the table for an hour

    It also depends what you mean by damage the wood - french polish may bloom at 50C or more, but you need a few hundred C to set fire to a timber joist or plywood sheet though it may make any paint finish  pong a bit before that.


  • Hi Mike

    i know that they don’t get as hot as traditional fluorescent fittings but was curious if they were suitable for mounting on a wooden surface. With very minimal information on either the fitting or the manufacturers website and their technical helpdesk not very convincing, I was interested as to how others fit these

  • I expect you are thinking of 559.4.1, mounting of luminaires and item (1). As LED domestic (etc) fittings are pretty low power, this does not need any thought as MIke says above, they do not get hot themselves and the infra-red intensity is very low so adjacent surfaces do not get heated either. You could fit then on or close to newspaper and there would be no significant fire risk. In the commercial industrial space discharge lights  (filament ones too but these have nearly ceased to exist) can be a significant risk because they may be powerful and emit significant infra-red radiation. Halogen lamp fittings often has a warning about mounting distances from adjacent surfaces, because they can have very sharp beam focus and a lot of infra-red output (about 80% of the rating). LW infra-red heaters also need to be watched too (the type that only heat people and objects, not the air) as the beamed intensity can be quite high.

  • Thanks for your replies. Yes I remember the old halogen fittings, I think that there was a stipulation that the front surface has to be a certain distance from a flammable surface. With my led vapourproof fittings it was the rear of the fitting which would be closest to the wooden surface that I was concerned about as I noticed from a previous install that after prolonged use it did get quite warm. Obviously not a problem if the fitting was suspended on chain as I mainly did in the past but as I mentioned, I plan to mount them to the wooden joist using the clips supplied with them and then loop in/out with conduit and single stranded cable. I suppose the fact the the fitting is held off the surface slightly by the clip helps also.


  • Bear in mind that the flash point of wood is in the region of 300 degrees C.  It's not going to ignite by being near something which is merely warm. DNO service heads and cut-out fuses have traditionally been mounted on a wooden panel, and the occasional overload (and thus heating of the main fuse and supply cable) doesn't seem to have burned many houses down over the years!

  • Did you get their tech reply in writing? ;)

    I couldn't find vapourproof fittings on the Ansell site, so not sure if domestic/commercial/industrial, and heat output, but you do seem concerned.

    Wooden joists are structural members. Warm light fittings might dry the wood and lower the ignition temperature. No idea if this could be a realistic problem, but there are Engineers here who might know.

  • No OM that will not be a problem. I am concerned by Peters worry about luminaire temperature. Fires cannot start at low temperatures, as Mike says at least 300 degrees C, unless the material is something like petrol which has a vapour, and secondly there is a good mixture of the vapour and oxygen. Clearly this cannot in the general case apply to solid materials, and even fine powders (like flour dust) or gunpowder need to have lots of oxygen (flour dust) or contain a powerful oxidising agent (gunpowder) to ignite, either in this case to cause an explosion. Flour is interesting in that the ignition is usually a static electric spark, but this is at 1000C at least!. Gunpowder needs a flame to light it (6-800C) or a spark (1000C), and just heating the powder to say 100C is perfectly safe. Anything which may get something above 60C or so now has a warning in the instructions, even my induction hobs warn me that the pans may get hot, so we are well into the age of lunacy warnings! Your lights presumably do not have this, so are safe mounted anywhere.

    1. Thanks everyone for their replies, it seems that My concerns may be unnecessary. I was probably of the opinion that the lights were ‘hot’ instead of ‘warm’. On another note, when I mentioned to Ansell technical support that I was using stranded cable in the terminations which are the lever spring  tool-less type, I was told to ensure that I twist the strands before insertion. I was always of the belief that this type of termination worked better by leaving the strands untwisted and have been doing it this way with wago’s and the like for years and the only time I twist the strands is with flex. I’m aware that this topic has been discussed and debated for years but not so much with wagos etc. What are your preferred techniques?