A while back, something I'd not heard of came up hear: namely the fact that
not all "celotex" PIR foams may be fire retardant.

Being concerned that I have 15 sheets in the shed which I wish to deploy in
the house, I tried a test today.

I cut a 15mm x 15mm ish 50mm long cuboid off, minus foil.

I set to it with a lighter then a blowtorch.

The lighter would cause a flame to briefly lick over the surface which them
went out after 2-3 seconds. Surface became black. Seemed impossible to
relight the black bits.

I tried it with a blowtorch - very similar: flame licked around a limited
area (I was holding the other end with bare fingers at this point). Flame
died. I repeated this all round one end until all surfaces were black. Small
amounts of foul smoke were emitted.

After that, directing a blowtorch at it caused the black layer to glow red
hot but the piece did not seem to want to relight.

The piece has shrunk at that end to around 10x10mm wide.

Does this sound like it's the flame retardant type? It seems so but I have
no other types to test, so I don't know what non retardant PIR would do.
Also this was a very small test sample - I don't know what happens if it was
exposed to a "real" house fire.

Cheers

Tim


--
Tim Watts

You know you need more insulation when the snow blanket on the roof makes
the house 3 degrees warmer...

In article ,
Tim W writes:
A while back, something I'd not heard of came up hear: namely the fact that
not all "celotex" PIR foams may be fire retardant.

Being concerned that I have 15 sheets in the shed which I wish to deploy in
the house, I tried a test today.

I cut a 15mm x 15mm ish 50mm long cuboid off, minus foil.

I set to it with a lighter then a blowtorch.

The lighter would cause a flame to briefly lick over the surface which them
went out after 2-3 seconds. Surface became black. Seemed impossible to
relight the black bits.

I tried it with a blowtorch - very similar: flame licked around a limited
area (I was holding the other end with bare fingers at this point). Flame
died. I repeated this all round one end until all surfaces were black. Small
amounts of foul smoke were emitted.

After that, directing a blowtorch at it caused the black layer to glow red
hot but the piece did not seem to want to relight.

The piece has shrunk at that end to around 10x10mm wide.

Does this sound like it's the flame retardant type? It seems so but I have

Yes - it won't sustain a flame.

no other types to test, so I don't know what non retardant PIR would do.

Burns more like a piece of expanded polystyrene (not quite as bad,
but very much different from your example).

Also this was a very small test sample - I don't know what happens if it was
exposed to a "real" house fire.

It will still give off all the same toxins if there's some other
fuel source roasting it, but it won't fuel a fire itself. Normally,
it's not exposed (at least in the living quarters of the house).

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember Tim W saying
something like:

Does this sound like it's the flame retardant type? It seems so but I have
no other types to test, so I don't know what non retardant PIR would do.
Also this was a very small test sample - I don't know what happens if it was
exposed to a "real" house fire.

Even if it is the flame-retardent type I wouldn't want to be exposed to
a naked wall of it which was being heated by a house fire and giving off
gobbets of smoke iyswim. Securely sealed in by plasterboard it's safe
enough, for at least the minimum amount of time.

Tim W wrote:
A while back, something I'd not heard of came up hear: namely the fact that
not all "celotex" PIR foams may be fire retardant.

Being concerned that I have 15 sheets in the shed which I wish to deploy in
the house, I tried a test today.

I cut a 15mm x 15mm ish 50mm long cuboid off, minus foil.

I set to it with a lighter then a blowtorch.

The lighter would cause a flame to briefly lick over the surface which them
went out after 2-3 seconds. Surface became black. Seemed impossible to
relight the black bits.

I tried it with a blowtorch - very similar: flame licked around a limited
area (I was holding the other end with bare fingers at this point). Flame
died. I repeated this all round one end until all surfaces were black. Small
amounts of foul smoke were emitted.

After that, directing a blowtorch at it caused the black layer to glow red
hot but the piece did not seem to want to relight.

The piece has shrunk at that end to around 10x10mm wide.

Does this sound like it's the flame retardant type? It seems so but I have
no other types to test, so I don't know what non retardant PIR would do.
Also this was a very small test sample - I don't know what happens if it was
exposed to a "real" house fire.

Cheers

Tim


Its all like that IME.

CeloTex BTW

Grimly Curmudgeon
wibbled on Thursday 07 January 2010 23:12

We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember Tim W saying
something like:

Does this sound like it's the flame retardant type? It seems so but I have
no other types to test, so I don't know what non retardant PIR would do.
Also this was a very small test sample - I don't know what happens if it
was exposed to a "real" house fire.

Even if it is the flame-retardent type I wouldn't want to be exposed to
a naked wall of it which was being heated by a house fire and giving off
gobbets of smoke iyswim. Securely sealed in by plasterboard it's safe
enough, for at least the minimum amount of time.

Thank you Grimly/Andrew/TNP. That sounds good news.

It's BallyTherm BTW.

So the next question is:

Where it's in loft spaces (fitted up inbetween and under the roof rafters)
is it necessary to cover it?

Those spaces are a cupboard door away from a habitable area. Obviously the
bits in the habitable area will be PB'd over. But I'm not totally relishing
applying PB inside roof voids - and it's not totally practical either in all
areas due to access (pipes etc in the way) though I *could* cover perhaps
80% of it. It's down at the last 2 foot towards the top of the wall leafs
that becomes difficult.

Would hardboard be better than nothing there where possible (it's thinner)?
Added complications would be that while I expect to go for 50mm between the
rafters and 50mm over, again down near the wall tops, I might have to step
down to zero or maybe 25mm if I'm lucky over the rafters - and steps in the
thickness don't help with applying sheet materials as you can imagine!

Bearing in mind it's foil covered - I haven't tried burning it through the
foil yet...

Cheers

Tim

--
Tim Watts

You know you need more insulation when the snow blanket on the roof makes
the house 3 degrees warmer...

Tim W wrote:
Grimly Curmudgeon
wibbled on Thursday 07 January 2010 23:12

We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember Tim W saying
something like:

Does this sound like it's the flame retardant type? It seems so but I have
no other types to test, so I don't know what non retardant PIR would do.
Also this was a very small test sample - I don't know what happens if it
was exposed to a "real" house fire.
Even if it is the flame-retardent type I wouldn't want to be exposed to
a naked wall of it which was being heated by a house fire and giving off
gobbets of smoke iyswim. Securely sealed in by plasterboard it's safe
enough, for at least the minimum amount of time.

Thank you Grimly/Andrew/TNP. That sounds good news.

It's BallyTherm BTW.

So the next question is:

Where it's in loft spaces (fitted up inbetween and under the roof rafters)
is it necessary to cover it?


Nope.

use foil tape to seal it to rafters

Those spaces are a cupboard door away from a habitable area. Obviously the
bits in the habitable area will be PB'd over. But I'm not totally relishing
applying PB inside roof voids - and it's not totally practical either in all
areas due to access (pipes etc in the way) though I *could* cover perhaps
80% of it. It's down at the last 2 foot towards the top of the wall leafs
that becomes difficult.

Would hardboard be better than nothing there where possible (it's thinner)?
Added complications would be that while I expect to go for 50mm between the
rafters and 50mm over, again down near the wall tops, I might have to step
down to zero or maybe 25mm if I'm lucky over the rafters - and steps in the
thickness don't help with applying sheet materials as you can imagine!

Bearing in mind it's foil covered - I haven't tried burning it through the
foil yet...

Dont worry. If it starts to burn, the house is already well alight.

Cheers

Tim

On 7 Jan, 23:12, The Natural Philosopher wrote:
Tim W wrote:
A while back, something I'd not heard of came up hear: namely the fact that
not all "celotex" PIR foams may be fire retardant.

Being concerned that I have 15 sheets in the shed which I wish to deploy in
the house, I tried a test today.

I cut a 15mm x 15mm ish 50mm long cuboid off, minus foil.

I set to it with a lighter then a blowtorch.

The lighter would cause a flame to briefly lick over the surface which them
went out after 2-3 seconds. Surface became black. Seemed impossible to
relight the black bits.

I tried it with a blowtorch - very similar: flame licked around a limited
area (I was holding the other end with bare fingers at this point). Flame
died. I repeated this all round one end until all surfaces were black. Small
amounts of foul smoke were emitted.

After that, directing a blowtorch at it caused the black layer to glow red
hot but the piece did not seem to want to relight.

The piece has shrunk at that end to around 10x10mm wide.

Does this sound like it's the flame retardant type? It seems so but I have
no other types to test, so I don't know what non retardant PIR would do.
Also this was a very small test sample - I don't know what happens if it was
exposed to a "real" house fire.

Cheers

Tim

Its all like that IME.

CeloTex BTW- Hide quoted text -

- Show quoted text -

Lots of the cheaper mimics are PUR rather than PIR, and PUR burns more
readily (much more readily in my limited experience of a sample of one
type).

Bolted
wibbled on Friday 08 January 2010 13:46

Lots of the cheaper mimics are PUR rather than PIR, and PUR burns more
readily (much more readily in my limited experience of a sample of one
type).

Luckily, the Ballytherm tech brochure states: "Ballytherm Insulation is a
foil-faced Polyisocyanurate (PIR) insulation board."

I don't think they're "cheap" (as in nasty) - more likely it's what came up
on the seconds market...

Another good point though and something worth checking if intending to
buy...

--
Tim Watts

You know you need more insulation when the snow blanket on the roof makes
the house 3 degrees warmer...

On 8 Jan, 16:00, Tim W wrote:
Bolted
* wibbled on Friday 08 January 2010 13:46

Lots of the cheaper mimics are PUR rather than PIR, and PUR burns more
readily (much more readily in my limited experience of a sample of one
type).

Luckily, the Ballytherm tech brochure states: "Ballytherm Insulation is a
foil-faced Polyisocyanurate (PIR) insulation board."

I wasn't really aiming that at your panels rather TNP's comment that
they are all like that (true wrt to real celotex, but not many
imitations).

I only found out because the tosser of a builder who did the shell of
our kitchen extension substituted a cheapo PUR instead of specced PIR
and the tosser of an architect couldn't be bothered to argue with him
(not his family being placed at increased risk). I checked to see if
I was being overly precious and demonstrated the happily burning foam
and pall of black smoke to architect who still lacked the balls to do
anything about it.

Tim W
wibbled on Thursday 07 January 2010 22:57

Sorry folks - I should have read the tech brochure before (TBH I only just
found it):

Quote:

"Fire

Ballytherm Insulation remains stable at
temperatures up to 400ºC; at higher
temperatures a protective char forms
on the surface, slowing the spread of
flame. Ballytherm insulation may be
used safely behind non-flammable
materials such as plasterboard.
The products have been fully tested in
accordance with B.S. 476: Part 7: 1997
Surface of Flame and have achieved a
Class 1 Rating."

Doh.

But some general knowledge about these things was very useful - the next
batch I get might not be Ballytherm.

--
Tim Watts

You know you need more insulation when the snow blanket on the roof makes
the house 3 degrees warmer...

John Rumm
wibbled on Thursday 07 January 2010 23:49


Would hardboard be better than nothing there where possible (it's
thinner)?

Worse I would have thought since it is directly combustible.

Makes sense.

Added complications would be that while I expect to go for 50mm between
the rafters and 50mm over, again down near the wall tops, I might have to
step down to zero or maybe 25mm if I'm lucky over the rafters - and steps
in the thickness don't help with applying sheet materials as you can
imagine!

Bearing in mind it's foil covered - I haven't tried burning it through
the foil yet...

There is a secondary fire risk issue when you have a whole space
enclosed in the stuff on the inside of the main thermal mass of the
building - that being that since it insulates so well, in a fire it
dramatically reduces the time taken for the enclosed space to reach the
spontaneous ignition temperature of anything in it. The PB in most
domestic situations retards this process somewhat though.



Thinking it might be a idea to stick a couple of smoke alarms in the voids -
being that's where all the cables run and interlink them with the rest of
the smoke alarms.

Cheers

Tim

--
Tim Watts

You know you need more insulation when the snow blanket on the roof makes
the house 3 degrees warmer...

Bolted
wibbled on Friday 08 January 2010 16:14

On 8 Jan, 16:00, Tim W wrote:
Bolted
wibbled on Friday 08 January 2010 13:46

Lots of the cheaper mimics are PUR rather than PIR, and PUR burns more
readily (much more readily in my limited experience of a sample of one
type).

Luckily, the Ballytherm tech brochure states: "Ballytherm Insulation is a
foil-faced Polyisocyanurate (PIR) insulation board."

I wasn't really aiming that at your panels rather TNP's comment that
they are all like that (true wrt to real celotex, but not many
imitations).

Made me look though

I only found out because the tosser of a builder who did the shell of
our kitchen extension substituted a cheapo PUR instead of specced PIR
and the tosser of an architect couldn't be bothered to argue with him
(not his family being placed at increased risk). I checked to see if
I was being overly precious and demonstrated the happily burning foam
and pall of black smoke to architect who still lacked the balls to do
anything about it.

Did you manage any come back against him, eg with BCO's help?

--
Tim Watts

You know you need more insulation when the snow blanket on the roof makes
the house 3 degrees warmer...

On 8 Jan, 16:21, Tim W wrote:
Bolted
* wibbled on Friday 08 January 2010 16:14

On 8 Jan, 16:00, Tim W wrote:
Bolted
wibbled on Friday 08 January 2010 13:46

Lots of the cheaper mimics are PUR rather than PIR, and PUR burns more
readily (much more readily in my limited experience of a sample of one
type).

Luckily, the Ballytherm tech brochure states: "Ballytherm Insulation is a
foil-faced Polyisocyanurate (PIR) insulation board."

I wasn't really aiming that at your panels rather TNP's comment that
they are all like that (true wrt to real celotex, but not many
imitations).

Made me look though

I only found out because the tosser of a builder who did the shell of
our kitchen extension substituted a cheapo PUR instead of specced PIR
and the tosser of an architect couldn't be bothered to argue with him
(not his family being placed at increased risk). *I checked to see if
I was being overly precious and demonstrated the happily burning foam
and pall of black smoke to architect who still lacked the balls to do
anything about it.

Did you manage any come back against him, eg with BCO's help?

No, it was just one battle in a constant war to get anything like the
spec out of the builder, I gave up on that one and just made the
ceiling as fireproof as I could when it came to fitting it out.