On 13/11/2019 21:25, Fredxx wrote:
On 13/11/2019 19:52:56, Chris B wrote:
This summer I had a new gas boiler installation in an airing cupboard
near the centre of the first floor.Â* Flue goes into the loft space and
across to a gable end.Â* Having just been up into the loft I see that
the fitters have disturbed a lot of insulation whilst installing the
flue and not bothered to put most of it back properly.

Are there any regulations about how close to gas flue pipes loft
insulation can be?

The flue pipe is plastic so presumably gets nothing more than warm.

The only rule regarding flues I'm aware of is they must be separated
from (combustible) timber by 75mm of air, or 25mm of incombustible
material. I wasn't aware of any requirements where the flue is buried in
insulation.

Interesting - I presume the distances from combustible materials were
defined for old-fashioned, very hot, metal flues. There would seem to be
no point in any separation at all with co-axial flues, where the outer
tube carries only ambient air; even less with co-axial flues on
condensing boilers, where even the inner, exhaust section is plastic!
Either there is something I haven't thought of or the regs are way out
of date for modern systems.

SteveW