PIR foam seems an effective solution to insulating a house, but the
information emerging from Grenfell indicates that it's not as fire
resistant as I (for one) assumed to be the case and can give off
significant amounts of toxic smoke.

It's also quite plausible that the current review of building regs will
introduce controls on PIR use. I know we don't always worry too much
about every details of the building regs, but they do provide sensible
guidance for most things, can affect availability of materials and can
sometimes lead to difficulties when selling a house.

I have assumed so far that, especially behind plasterboard, the risk was
very low, especially when there are many tons of dry timber in the house
and in any case fires are relatively rare events.

There don't seem to be any practical alternatives but is it time to
question PIR use for domestic insulation upgrades?

"GMM" wrote in message
news
PIR foam seems an effective solution to insulating a house, but the
information emerging from Grenfell indicates that it's not as fire
resistant as I (for one) assumed to be the case and can give off
significant amounts of toxic smoke.

It's also quite plausible that the current review of building regs will
introduce controls on PIR use. I know we don't always worry too much
about every details of the building regs, but they do provide sensible
guidance for most things, can affect availability of materials and can
sometimes lead to difficulties when selling a house.

I have assumed so far that, especially behind plasterboard, the risk was
very low, especially when there are many tons of dry timber in the house
and in any case fires are relatively rare events.

There don't seem to be any practical alternatives but is it time to
question PIR use for domestic insulation upgrades?

this is where all the upgrading of dwellings got us....things made sense
when the only requirement was the U value of walls to be 1 and roofs 0.6
.........and a timber frame house with fibreglass quilt in the 42 stud
exceeded that requirement .... and warm deck unvented upside down flat roofs
were the start of the use of materials like celotex.....

On 17/07/2017 11:40, Jim GM4DHJ ... wrote:
"GMM" wrote in message
news
PIR foam seems an effective solution to insulating a house, but the
information emerging from Grenfell indicates that it's not as fire
resistant as I (for one) assumed to be the case and can give off
significant amounts of toxic smoke.

It's also quite plausible that the current review of building regs will
introduce controls on PIR use. I know we don't always worry too much
about every details of the building regs, but they do provide sensible
guidance for most things, can affect availability of materials and can
sometimes lead to difficulties when selling a house.

I have assumed so far that, especially behind plasterboard, the risk was
very low, especially when there are many tons of dry timber in the house
and in any case fires are relatively rare events.

There don't seem to be any practical alternatives but is it time to
question PIR use for domestic insulation upgrades?

this is where all the upgrading of dwellings got us....things made sense
when the only requirement was the U value of walls to be 1 and roofs 0.6
........and a timber frame house with fibreglass quilt in the 42 stud
exceeded that requirement .... and warm deck unvented upside down flat roofs
were the start of the use of materials like celotex.....


Indeed: I'd just like to make my place warmer and more energy
efficient. Precise U-values aren't really all that important unless
building control become involved, when it all becomes unrealistic in
many situations for an old house. PIR looked like a good solution, but
there's no point in having a warm house that you can't ever sell or is
going to kill you

On 17/07/2017 12:02, Huge wrote:
On 2017-07-17, GMM wrote:

[10 lines snipped]

I have assumed so far that, especially behind plasterboard, the risk was
very low, especially when there are many tons of dry timber in the house

Every time I burn left-over building materials (most recently, any parts
of my old kitchen actually made of real wood, which I cut up and put in
the woodburner), I muse on how inflammable houses actually are. And why
I change the smoke detector batteries every year, whether they "pip" or
not. I think PIR boards are the least of our worries.


I'd still reckon that if I'm not out by the time a fire gets through
plasterboard and the PIR starts burning then I won't be getting out.
Especially as - like many - I sleep above a lot of other stuff which may
well be noxious - eg carpet underlay.

--
Robin
reply-to address is (intended to be) valid

On 17/07/17 11:52, GMM wrote:

Indeed: I'd just like to make my place warmer and more energy
efficient. Precise U-values aren't really all that important unless
building control become involved, when it all becomes unrealistic in
many situations for an old house. PIR looked like a good solution, but
there's no point in having a warm house that you can't ever sell or is
going to kill you

It's not going to cause either of those problems in a typical house.

Yes, the smoke is toxic and so is the smoke from all your synthetic
furniture components.

Given it is currently recognised by building regs and is installed in
millions of homes, it's not going to make anything unsellable either.

On Mon, 17 Jul 2017 11:33:19 +0100, GMM wrote:

PIR foam seems an effective solution to insulating a house, but the
information emerging from Grenfell indicates that it's not as fire
resistant as I (for one) assumed to be the case and can give off
significant amounts of toxic smoke.

Fire resistance is the ability of a material to withstand a standard
fire resistance test. Kingspan/Cellotex/polyisocyanurate foams are
not significantly fire resistant. The blowing agent used to create
PIR foam was originally CFC-11 which was replaced by HCFC-141b,
neither were flammable. In turn HCFC-141b was replaced by pentane
because of its lower global warming potential. Pentane is highly
flammable.

Applying a flame to PIR board will create an instant burn (from the
Pentane released) but it will not by itself support combustion, remove
the flame and it will go out. Put it into a vertical wind tunnel with
a fire at the bottom and surrounded by more flammable materials and it
will help support combustion - which is what seems to have occurred at
Grenfell. One significant product of combustion of PIR board is
Hydrogen Cyanide, however the more normal products of combustion such
as Carbon Monoxide are a greater risk as they do not require a raging
fire to be produced and will kill you in your sleep before you realise
there is a fire. Very few people die of burns in house fires, most
are asphyxiated.

If used as internal retrofit insulation in a house PIR will be covered
in plasterboard which is very fire resistant. If you lined your whole
house internally with plasterboard lined Kingspan you will not have
increased the risk from fire - other things burning within the house
will have killed you long before the PIR foam degrading in the heat
becomes a threat. PIR foam used as cavity wall insulation has no risk
at all attached to it nor would it if used as part of external
cladding on low rise properties.

It's also quite plausible that the current review of building regs will
introduce controls on PIR use.

I doubt if this will occur in properties other than high rise. It is
the use of composite claddings on high rise buildings where attention
will focus, not PIR board. Had the building been clad only in PIR
board the fire would not have spread as it did. (But of course PIR
board alone is not suitable as cladding).

I know we don't always worry too much
about every details of the building regs, but they do provide sensible
guidance for most things, can affect availability of materials and can
sometimes lead to difficulties when selling a house.

I have assumed so far that, especially behind plasterboard, the risk was
very low,

It is vanishing low.

especially when there are many tons of dry timber in the house
and in any case fires are relatively rare events.

There don't seem to be any practical alternatives but is it time to
question PIR use for domestic insulation upgrades?

No.

On Monday, 17 July 2017 11:33:21 UTC+1, GMM wrote:

PIR foam seems an effective solution to insulating a house, but the
information emerging from Grenfell indicates that it's not as fire
resistant as I (for one) assumed to be the case and can give off
significant amounts of toxic smoke.

It's also quite plausible that the current review of building regs will
introduce controls on PIR use. I know we don't always worry too much
about every details of the building regs, but they do provide sensible
guidance for most things, can affect availability of materials and can
sometimes lead to difficulties when selling a house.

I have assumed so far that, especially behind plasterboard, the risk was
very low, especially when there are many tons of dry timber in the house
and in any case fires are relatively rare events.

There don't seem to be any practical alternatives but is it time to
question PIR use for domestic insulation upgrades?

There's papercrete, which is very low flammability, self extinguishing & nontoxic. I don't know of anyone using it commercially.

And there are always soft insulations like fibreglass, rockwool.


NT

On 17/07/17 13:40, Peter Parry wrote:

In turn HCFC-141b was replaced by pentane
because of its lower global warming potential. Pentane is highly
flammable.

Genius...

....


If used as internal retrofit insulation in a house PIR will be covered
in plasterboard which is very fire resistant. If you lined your whole
house internally with plasterboard lined Kingspan you will not have
increased the risk from fire - other things burning within the house
will have killed you long before the PIR foam degrading in the heat
becomes a threat. PIR foam used as cavity wall insulation has no risk
at all attached to it nor would it if used as part of external
cladding on low rise properties.

Well - not so much if you deploy it in the attic... I did, but I did
cover 90% in PB (can't get down into the eaves to do that bit).
I did it to stop it getting dinged but peopel moving junk in the attic,
but fire resistance was also in my mind, seeing as that's where most of
the mains wiring and SELV PSUs are.

That roof on the Weybridge health Centre fire that trashed the building top
floor in under half an hour was supposed to have been to the building regs.
I do sometimes wonder who is in charge of deciding what a real world
situation actually is!
Brian

--
----- -
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please!
"Jim GM4DHJ ..." wrote in message
news

"GMM" wrote in message
news
PIR foam seems an effective solution to insulating a house, but the
information emerging from Grenfell indicates that it's not as fire
resistant as I (for one) assumed to be the case and can give off
significant amounts of toxic smoke.

It's also quite plausible that the current review of building regs will
introduce controls on PIR use. I know we don't always worry too much
about every details of the building regs, but they do provide sensible
guidance for most things, can affect availability of materials and can
sometimes lead to difficulties when selling a house.

I have assumed so far that, especially behind plasterboard, the risk was
very low, especially when there are many tons of dry timber in the house
and in any case fires are relatively rare events.

There don't seem to be any practical alternatives but is it time to
question PIR use for domestic insulation upgrades?

this is where all the upgrading of dwellings got us....things made sense
when the only requirement was the U value of walls to be 1 and roofs 0.6
........and a timber frame house with fibreglass quilt in the 42 stud
exceeded that requirement .... and warm deck unvented upside down flat
roofs were the start of the use of materials like celotex.....

On Mon, 17 Jul 2017 11:33:19 +0100, GMM wrote:

PIR foam seems an effective solution to insulating a house, but the
information emerging from Grenfell indicates that it's not as fire
resistant as I (for one) assumed to be the case and can give off
significant amounts of toxic smoke.

It's also quite plausible that the current review of building regs will
introduce controls on PIR use. I know we don't always worry too much
about every details of the building regs, but they do provide sensible
guidance for most things, can affect availability of materials and can
sometimes lead to difficulties when selling a house.

I have assumed so far that, especially behind plasterboard, the risk was
very low, especially when there are many tons of dry timber in the house
and in any case fires are relatively rare events.

There don't seem to be any practical alternatives but is it time to
question PIR use for domestic insulation upgrades?

In relation to which, did you see

https://www.theguardian.com/uk-news/...dlords-warned-
stripping-cladding-from-towers-could-increase-fire-risk

Some numptys stripping the cladding off to expose insulation underneath
which is flammable when not covered by cladding.

Don't Panic!!

Cheers



Dave R

--
AMD FX-6300 in GA-990X-Gaming SLI-CF running Windows 7 Pro x64

---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

On 17/07/2017 12:10, Tim Streater wrote:
In article , Huge
wrote:

On 2017-07-17, GMM wrote:

[10 lines snipped]

I have assumed so far that, especially behind plasterboard, the risk
was very low, especially when there are many tons of dry timber in
the house

Every time I burn left-over building materials (most recently, any parts
of my old kitchen actually made of real wood, which I cut up and put in
the woodburner), I muse on how inflammable houses actually are.

+1

And why you should organise an emergency grab-bag containing passports
and the like, which can be taken out in case of fire. Remembering that
once a fire gets hold, most houses will go up and become dangerous in
minutes.

+1

Yup concentrate on the things you can control - smoke alarms, emergency
lighting, usable escape routes etc.

To an extent any insulation can make fire spread more rapid as it will
often allow room temperatures to rise more quickly. However fire is a
rare event and heat loss a common one, so you need to keep a perspective.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

Polystyrene is far worse than kingspan and celotex - I know someone who's installing it on the sly - no no no.

Try burning a bit with a lighter and watch it spread!

I did this test with yellow foam and pinkgrip foam and discovered its very flammable, now i use the slightly more expensive firefoam for all my foaming jobs insulating this old house - i buy a dozen cans at a time! Use it to stick kingspan seconds to walls and the gaps between them, and sticking Plasterboard or OSB to the kingspan, no metal screws coldbridging coldness in from outside

[george]

On 17/07/2017 13:40, Peter Parry wrote:
In turn HCFC-141b was replaced by pentane
because of its lower global warming potential. Pentane is highly
flammable.

Yes, that's why we use it for petrol. It's a liquid at room temperature.

How on earth do they use it for a foaming agent?

Andy

On 17/07/17 21:29, Vir Campestris wrote:
On 17/07/2017 13:40, Peter Parry wrote:
In turn HCFC-141b was replaced by pentane
because of its lower global warming potential. Pentane is highly
flammable.

Yes, that's why we use it for petrol. It's a liquid at room temperature.

How on earth do they use it for a foaming agent?

Andy

Did he mean butane?

Tim Watts wrote:

Vir Campestris wrote:

Peter Parry wrote:

In turn HCFC-141b was replaced by pentane because of its lower
global warming potential. Pentane is highly flammable.

Yes, that's why we use it for petrol. It's a liquid at room temperature.
How on earth do they use it for a foaming agent?

Did he mean butane?

I didn't know what blowing agent they used, you'd think that for FR it
might be obvious to use CO2 rather than a flammable gas and it seems it
*is* obvious enough that some materials use it ...

http://www.lindeplastics.com/foaming-co.php

Even if the difference between releasing a bit of pentane, and releasing
some CO2 was minute in fire terms, you'd think they'd do it just for the
ecobollox "carbon-negative" credentials ...

On Mon, 17 Jul 2017 21:36:21 +0100, Tim Watts
wrote:

On 17/07/17 21:29, Vir Campestris wrote:
On 17/07/2017 13:40, Peter Parry wrote:
In turn HCFC-141b was replaced by pentane
because of its lower global warming potential. Pentane is highly
flammable.

Yes, that's why we use it for petrol. It's a liquid at room temperature.

How on earth do they use it for a foaming agent?

Andy

Did he mean butane?

No, Pentane. Butane has been tried but it is more difficult to
achieve even foam density than with Pentane.

In article , Brian Gaff
wrote:
That roof on the Weybridge health Centre fire that trashed the building
top floor in under half an hour was supposed to have been to the building
regs. I do sometimes wonder who is in charge of deciding what a real
world situation actually is! Brian

Building Regs don't control how people furnish their property nor what they
store there.

--
from KT24 in Surrey, England

On 17/07/2017 18:23, DICEGEORGE wrote:
Polystyrene is far worse than kingspan and celotex - I know someone who's installing it on the sly - no no no.

Try burning a bit with a lighter and watch it spread!

I did this test with yellow foam and pinkgrip foam and discovered its very flammable, now i use the slightly more expensive firefoam for all my foaming jobs insulating this old house - i buy a dozen cans at a time! Use it to stick kingspan seconds to walls and the gaps between them, and sticking Plasterboard or OSB to the kingspan, no metal screws coldbridging coldness in from outside


I assume you are not worried about the risks which follow from omitting
the mechanical fixings which stop the plasterboard and insulation
falling on you when you're trying to escape a fire (or on the fire
service when they are trying to rescue you).

I assume you also quantified the loss from cold bridging you'd suffer
with what are IIRC are the recommended 3 fixings per sheet. Last ones I
saw being used month had a cross-section of 9mm2 so that's 27mm2 per
sheet - or 0.0000094 of the area of a full board. And of course those
fixing go into the underlying wall, not the outside.



--
Robin
reply-to address is (intended to be) valid

On 17/07/2017 11:33, GMM wrote:

PIR foam seems an effective solution to insulating a house, but the
information emerging from Grenfell indicates that it's not as fire
resistant as I (for one) assumed to be the case and can give off
significant amounts of toxic smoke.

I suspect there is more to this than there seems at first glance. PIR
foam without any fire retardant additives burns moderately though not as
fast as PU foam which unmodified burns like a firelighter. Both produce
dense black smoke with copious CO and traces of cyanide in it. I'd be
more worried about the hot soot and CO to be honest.

I happen to have some rigid PU building insulation foam (ICI prototype
stuff) from the late 1960's in my parents loft. I took a piece and tried
to set light outside (taking appropriate safety precautions). It had one
of the earliest fire retardant formulations in it (which actually makes
the smoke even more toxic if it burns). The backing paper burned off and
the surface of the foam charred but that was all. I was quite surprised
since I was worried that the foam might have been original raw batch
without any additives. If they could make PU foam resist fire at that
level back in the 1960-70's I am sure they can make PIR do the same.

Snag is that the blowing agents have changed and some today may well be
using pentane (which is itself a flammable gas).

However there is still a possibility of someone buying a cheap grade
that is only suitable for cavity wall insulation where it is surrounded
by inert brick/breezeblock walls on either side excluding the air and
then strapping it to the outside of a block of high rise flats.

It's also quite plausible that the current review of building regs will
introduce controls on PIR use. I know we don't always worry too much
about every details of the building regs, but they do provide sensible
guidance for most things, can affect availability of materials and can
sometimes lead to difficulties when selling a house.

I have assumed so far that, especially behind plasterboard, the risk was
very low, especially when there are many tons of dry timber in the house
and in any case fires are relatively rare events.

Structural timber doesn't catch all that easily unless you are very very
unlucky (once a fire takes hold all bets are off). Paper and cardboard
and thin wooden furniture are much more vulnerable. Very old foam
settees from the pre fire retardant era are potentially lethal.

Now is good time to check that yours has a fire certificate stitched
into the underside of the cushions (especially if you are a smoker).

There don't seem to be any practical alternatives but is it time to
question PIR use for domestic insulation upgrades?

It might be appropriate to ban the sale of the cheapest nastiest variant
which is only safe to use *inside* the cavity of an inert brick wall or
behind plasterboard (or at least add warnings to that effect).

I notice Celotex have voluntarily stopped selling their RS5000 grade as
used on Grenfell tower.

--
Regards,
Martin Brown

On 17/07/2017 11:33, GMM wrote:
PIR foam seems an effective solution to insulating a house, but the
information emerging from Grenfell indicates that it's not as fire
resistant as I (for one) assumed to be the case and can give off
significant amounts of toxic smoke.

It's also quite plausible that the current review of building regs will
introduce controls on PIR use. I know we don't always worry too much
about every details of the building regs, but they do provide sensible
guidance for most things, can affect availability of materials and can
sometimes lead to difficulties when selling a house.

I have assumed so far that, especially behind plasterboard, the risk was
very low, especially when there are many tons of dry timber in the house
and in any case fires are relatively rare events.


Quite - for a fire to take hold, the insulation material would, I'd have
thought, be the least of your worries. In my case:

On solid walls, mechanically fixed behind 12.5mm plasterboard. There's
simply nothing to burn so I can't see how it would add to a fire. Once
hot enough and exposed, there is the issue of poisonous gas, but I think
the house would be pretty much gutted by that point;

Ground floor, between joists, fixed with fire retardant foam. Assuming
the fire started in the cellar (quite a few electrical bits and pieces
down there, so possible) I'd have thought if anything it would inhibit
the spread of fire by protecting the floorboards - until the point that
the fire had reached such a heat that the foil fails, the foam melts,
and the floorboards are exposed. In the meantime, the joists can
smoulder but there's not that much showing to actually burn;

In the roof space, between rafters, fixed with fire retardant foam,
faced to the inside with plasterboard, open to the roof space. The fire
would have to have spread from another property, or timber in the roof
space would have to in some way catch fire, maybe from an internal fire.
Again, I'd have thought the insulation would in the short term inhibit
the spread of fire because the timbers are less exposed.

There don't seem to be any practical alternatives but is it time to
question PIR use for domestic insulation upgrades?

I suppose they could look to developing something completely inert, even
if that does effectively turn the home into an oven-furnace.

But as things stand, I don't see PIR as a prime source of fire hazard in
low rise ( 4 storey). Timber and furnishings and other 'developments'
like laminates would be a bigger problem, and households should make
sure they have working fire alarms fitted in the first instance.

--
Cheers, Rob