....from the technical manager of a lighting manufacturer: "F-mark" and
"Fire-rated" are not the same thing.

If a downlight carries the F-mark (letter "F" in an upside-down
triangle), it can be mounted on combustible surfaces (e.g. wood). It
does not mean that the light is fire retardant.

If a downlight is fire-rated, it incorporates intumescent materials
which ensure that the ceiling maintains its fire and acoustic integrity
in accordance with Building Regulations.

--------------

I have been searching for 12V downlights for my lath-and-plaster
ceiling. My electrician said that they needed to have a fire hood or be
fire-rated. I think that he is wrong, since the ceiling itself does not
have a fire rating. However, I do need downlights that carry the
F-mark. Ironically, most suppliers of cheap downlights derate their
lights to 35W to allow them to carry the F-mark. So I may have to buy
fire-rated downlights after all if I want to get a 50W version!

Which is the correct way up for a triangle?
--
Graham.

Graham wrote:
Which is the correct way up for a triangle?

*
***
*****
*******

wrote:

If a downlight carries the F-mark [...] It
does not mean that the light is fire retardant.

Are all the fire-rated fittings also F-marked / inherently F-markable ?

Andy Dingley wrote:

Are all the fire-rated fittings also F-marked / inherently F-markable ?

I've looked at a number of fire-rated downlights and they all seem to
carry the F-mark. It is an assumption though on my part, Andy, that ANY
fire-rated light is automatically suitable for mounting on a
combustible surface.

wrote:
Andy Dingley wrote:

Are all the fire-rated fittings also F-marked / inherently F-markable ?

It is an assumption though on my part, Andy, that ANY
fire-rated light is automatically suitable for mounting on a
combustible surface.

That's what I'd assume too, but is it really valid? One means that
it's resistant to external heat, the other means that it doesn't
transmit excess heat to its support. Commercially it would make sense
for one to imply the other, but technically it seems less sure.

wrote:

I have been searching for 12V downlights for my lath-and-plaster
ceiling. My electrician said that they needed to have a fire hood or be
fire-rated. I think that he is wrong, since the ceiling itself does not
have a fire rating.

It also depends where the lights are going. This article may be of
interest:
http://www.iee.org/Publish/WireRegs/...n_ceilings.pdf

--
Andy