Author Topic: Safety of Polyuerathane Insulation?  (Read 2634 times)

Offline Manxmodder

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Safety of Polyuerathane Insulation?
« on: August 06, 2016, 09:50:26 AM »
I have been meaning to ask a few questions about the safety of foil backed polyurethane insulation boards for a while now...so here's a couple to start.

I have a large stock of Kingspan polyurethane insulation boards in varying thickness's (25mm, 50mm,75mm) which I plan on using to insulate various parts of my 105 year old stone built house with.

My concern with  polyurethane insulation is it is easily set alight and burns ferociously with acrid and toxic fumes when burning.

I have already insulated between the roof rafters with 75mm insulation,leaving a 25mm air gap above for breathable ventilation.

A thought occurs to me that if the property roof was hit by a direct lightning strike,how likely is the risk of the insulation being set alight? Should I consider,for safety purpose, installing a lightning conductor strip and earth rod?........OZ.



Helixes aren't always downward spirals,sometimes they're screwed up

Offline wgw

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Re: Safety of Polyuerathane Insulation?
« Reply #1 on: August 07, 2016, 06:10:41 AM »
Well- at the risk of getting shot down- I would not worry, the insulation will be modern stuff and is self-extinguishing to some extent. It takes quite a lot to get it started when I want to burn it. I'm using kingspan and plain foam and never had any worries. If you get a lightning strike the insulation will be the least of your worries.

Offline Fergus OMore

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Re: Safety of Polyuerathane Insulation?
« Reply #2 on: August 07, 2016, 08:44:18 AM »

I thought that this was all a bit of a sad joke. 13 French party goers in Rouen died when a birthday cake's candles set fire to the ceilings and walls.

One can only hope that the remark was aimed at another type of construction material.

Regards

Norman

Offline chipenter

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Re: Safety of Polyuerathane Insulation?
« Reply #3 on: August 07, 2016, 09:33:03 AM »
I have had to fill the gaps in a roof with intumecent polyurethane foam to protect the timber but not the kingspan .
Jeff

Offline John Stevenson

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Re: Safety of Polyuerathane Insulation?
« Reply #4 on: August 07, 2016, 09:38:20 AM »

I thought that this was all a bit of a sad joke. 13 French party goers in Rouen died when a birthday cake's candles set fire to the ceilings and walls.


Regards

Norman

What do you expect when they have 146 candles on a birthday cake  :loco:
John Stevenson

Offline nrml

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Re: Safety of Polyuerathane Insulation?
« Reply #5 on: August 07, 2016, 04:58:20 PM »
I would have thought the manufacturers would have to meet some standard as far as fire safety is concerned before their product is approved for sale. Unless my local environment made my house more vulnerable than average to lightning strikes, I wouldn't bother taking any special precautions.

Offline PekkaNF

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Re: Safety of Polyuerathane Insulation?
« Reply #6 on: August 08, 2016, 01:12:52 AM »
I would install lighting protection that regulation requires and sleep my night well.

Just wisited the house of one excentric gold smith build in 1950's. He was afraid of the fire and thugs, The house exterior was build from firebricks, roof was copper and all lighting and fire proections that mouney could by that time. Nasement had a safe with 20 cm thick steel door, bomb shelter/safe room and secret tunnelt to extra exit into garden.

Pekka

Offline Eugene

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Re: Safety of Polyuerathane Insulation?
« Reply #7 on: August 08, 2016, 02:56:59 AM »
Kingspan, the company, through their technical department can advise on any application of their materials from every aspect including that of fire regulations. Their website also carries solid information on the subject. http://www.kingspaninsulation.co.uk/Knowledge-Base/Facades---Fire-Safety.aspx If you have any doubts gives them a call.

Kingspan products are for the main part constructional, they aren't used as interior wall cladding or for ceilings where there is a decorative requirement. Thus you tend to find them inside cavity walls, in floors and under exterior cladding.

The real killer in a fire isn't correctly specified polyurethane inside walls and floors, but polystyrene in the form of tiles and coving; it burns very fiercely emitting dense toxic fumes. I suspect that maybe what got the unfortunates in the French Bistro

A lot of this polystyrene stuff was applied in the 70s without much thought; not sure what the fire regs say about it now.

No connection to Kingspan other than as a satisfied end user.

Eug

Offline Manxmodder

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Re: Safety of Polyuerathane Insulation?
« Reply #8 on: August 08, 2016, 09:10:18 AM »
I would install lighting protection that regulation requires and sleep my night well.

Just wisited the house of one excentric gold smith build in 1950's. He was afraid of the fire and thugs, The house exterior was build from firebricks, roof was copper and all lighting and fire proections that mouney could by that time. Nasement had a safe with 20 cm thick steel door, bomb shelter/safe room and secret tunnelt to extra exit into garden.

Pekka

Agree,Pekka. The other reason I was thinking so much about lightning protection is where I live we are fairly high on the hill,and lightning storms tend to move directly through this area,heading towards the North.

We are experiencing a lot more of these storms over the last few years and the intensity and strike count have also increased quite noticeably over that period.

I am considering putting a conductor strip down through one of the redundant stone built chimney stacks and connecting to an earthing rod buried in the ground in the area under the house.

That way it isn't even unsightly or visible from the exterior.....Anyone see any problems with that scheme?.....OZ
Helixes aren't always downward spirals,sometimes they're screwed up

Offline Pete W.

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Re: Safety of Polyuerathane Insulation?
« Reply #9 on: August 08, 2016, 10:05:03 AM »

SNIP!

I am considering putting a conductor strip down through one of the redundant stone built chimney stacks and connecting to an earthing rod buried in the ground in the area under the house.

That way it isn't even unsightly or visible from the exterior.....Anyone see any problems with that scheme?.....OZ

Somewhere in my 'filing system'  :lol:   :lol:   :lol:  I have some literature on lightning protection.  I think the company's name is Furze.  One of the snippets I remember is that the copper strip must be of adequate cross sectional area - that's fairly obvious.  What's not so obvious to the layman is that the inductance of the lightning conductor must also be minimised.  A lightning strike is, after all, a high amplitude but brief pulse of current.  Apparently just tailoring the strip out over a cornice and back again can contribute enough inductance to seriously reduce the effectiveness of the conductor - it doesn't need to be complete turns. 
Best regards,

Pete W.

If you can keep your head when all about you are losing theirs, you haven't seen the latest change-note!

Offline Joules

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Re: Safety of Polyuerathane Insulation?
« Reply #10 on: August 08, 2016, 10:21:23 AM »
It's not so much it reduces the effectiveness, that any sharp bends try to straighten them selves out during a strike, ripping out the fasteners or the masonry they are connected too, with explosive force.  The rod needs to be as straight as possible all the way to the ground.
Just get doing and make swarf, you can decide what its going to be later.   :thumbup:

Online awemawson

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Re: Safety of Polyuerathane Insulation?
« Reply #11 on: August 08, 2016, 10:41:50 AM »
Pete, if that company is anything to do with Colin Furze there'll be sparks all over the place  :bugeye:

http://www.colinfurze.com/
Andrew Mawson
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Offline efrench

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Re: Safety of Polyuerathane Insulation?
« Reply #12 on: August 08, 2016, 01:21:13 PM »
Isn't a stone house already earthed?

Offline howsitwork?

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Re: Safety of Polyuerathane Insulation?
« Reply #13 on: August 08, 2016, 02:53:46 PM »
few years back one of the neighbours had a direct hit on the roof. It earthed out through the radiators and blew the tank up but no one hurt.

Re Kingspan it willfly across the metalfoil possibly but the makers will advise.

A decent tall metal pole with a  substantial lead to the ground will attract lightening to it.


Offline Will_D

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Re: Safety of Polyuerathane Insulation?
« Reply #14 on: August 08, 2016, 05:00:47 PM »
IIRC a lightning conductor is NOT designed to conduct a lightning strike to ground!

The way lightning discharges work is by a positive charge builds up on high points like chimneys. The clouds provide the negative charge. Once the potential difference (of a high spot) exceeds the ionisation potential of the atmosphere then Flash / Bang.

So how does the conductor work?

The charge builds up at the pointed conductor and is then conducted to ground so that the positive charge on your chimney is reduced to a safe level and the cloud then has to look for another large build up of positive charge.

As I said IIRC!! Not sure if a 25 x 3 mm copper strip can handle a strike!!
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Offline hermetic

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Re: Safety of Polyuerathane Insulation?
« Reply #15 on: August 09, 2016, 03:29:09 PM »
Spot on WillD!!