SIPS and fire!!

[Hobbiniho]

Following a horrific fire at a modern hotel local to me two nights ago (everyone got out safe) i have wondered if there are any opinions on the use of SIPS from a fire safety point of view, im sure everyone is aware of grenfell but maybe not the problems associated with rigid polyurethane foam type insulation when subjected to fire, for the people that have SIPS houses, was fire risk taken into consideretion or even talked about when considering build method??.

 

I know i am talking about a commercial building that has been built using a pre-fab style of construction, but the point im am trying to make is that SIPS seem to behave very poorly in a fire compared to more traditional build methods, some interesting comments have been made locally that we now live in a "build it cheap and throw it away after a few years" society.

 

https://www.shetnews.co.uk/2020/07/27/investigation-underway-after-huge-fire-destroys-moorfield-hotel/

https://www.youtube.com/watch?v=4wz9KRTgVCc

[joe90]

I have never been a fan of “plastic” insulation because of the fire risk, I have this insulation below my slab but it’s encased in concrete so very unlikely to catch fire. I cannot believe that building regs allowed Grenfell to be insulated as it was and hope we all learn that lesson.

[scottishjohn]

greenfell was nothing like a sips construction 

 the main problem with greenfell as I understand it was

a man had a fire with dodgy fridge --he opened the window  and door of flat to get rid of smoke --which he should not have done --that allowed  the fire to get bigger

flames  to go outside , -made its way to the air gap behind the cladding-then that made a draft  like a chimney -- and-the rest you saw  -

sips panels are sealed units so fire danger is no more than any timber framed house -maybe less cos there will be less gaps in between panels for air ingress to fuel the fire

remember the fire triangle -fuel - oxygen -heat 

remove any one and  no fire

most foams will self extinguish if not a good source of oxygen -eg outside  any amount of it-

 only true fireproof insulation is mineral wool and you need twice as much of it as a foam product

the insulation of any type of product is  by the trapping of air in the material 

 

 

[ProDave]

Do you even know that building was made of SIPS?  so it seems to have started in the roof, I wonder what caused that?

 

Once a fire gets hold like that, it is very unsuual indeed for the building to be saved, regardless of construction method. This near us, an entire brick / stone built primary school completely lost due to a fire thought to have been started by a laptop computer catching fire https://www.bbc.co.uk/news/uk-scotland-highlands-islands-51614060

 

 

[ma9mwah]

Would a new hotel like this be required to have sprinklers installed? and if they are would that include the roof space?

[joe90]

36 minutes ago, scottishjohn said:

only true fireproof insulation is mineral wool and you need twice as much of it as a foam product

Which is why I have an extra wide cavity filled with it. As I understand it foam insulation is also a petroleum product so not “green”.

[Mr Punter]

It was suspicious that the hotel was due to close at the end of the month as Total did not renew their contract.

[scottishjohn]

11 minutes ago, Mr Punter said:

It was suspicious that the hotel was due to close at the end of the month as Total did not renew their contract.

looked like TF construction with render  looking at pictures EDIT --CHANGED MY MIND  LOOKS LIKE SOME OTHER SORT OF PREFAB PANELS SYSTEM -

my guess no sprinkler system 

 the fact everyone got out shows the fire alarm system was working --maybe it burnt that bad due to lack of water pressure for the fire fighters?

now if they had built it with ISOTEX /DURISOL-the most of it would still be standing just the roof gone 

one advantage of concrete  

 

Edited July 29, 2020 by scottishjohn

[joe90]

I remember studying straw bale build a few years ago and worried about fire, apparently it’s only during its construction that it’s dangerous, because the straw is lime rendered all over its cocooned in limestone. I saw a photo of the aftermath of the fires in California and the only walls standing in a group of houses was a straw bale build, roof all gone (timber) but walls still standing when everything else around it was razed to the ground! Interesting!.

[nod]

Part of my job is supply and fitting fire protection 

While TF hotels Student accommodation is really good With fire stops at every junction Smoke shafts running the full height of the building 

The fire protection is poor on TF houses 

While most work towards high airtightness 

Fire protection isn’t minimal 

 

Whiles ours is brick built 

I still installed fire baffles in all ceiling lights and the sockets that are in the few studs 

It doesn’t matter how many layers of plasterboards there are if there are sockets and switches fixed to a timber pattress 

 

[Ferdinand]

The Worcester Park fire last year (?) was close to the type of construction being discussed.

 

https://www.bbc.co.uk/news/uk-england-london-49630496

[joe90]

No mention of its construction or insulation method?

[Mr Punter]

1 hour ago, joe90 said:

No mention of its construction or insulation method?

 

There was on the youtube link.  Deffo sips. https://www.youtube.com/watch?v=4wz9KRTgVCc

[AliG]

I just watched the Youtube. I would be worried if my house had that much combustible material inside it.

 

We have sprinklers in the second floor and the sprinkler guy was here today. He said he would have put them all through the house. I said that I  tend not to worry about it as there is hardly anything combustible in the house. The most combustible part is the roof with wooden rafters and PIR insulation.

 

I think the regs are quite general and don't take different construction methods into account very well. Putting polyurethane inside all the interior walls of a building would mean that if a fire took hold the whole place was very likely to go. It is a very strange thing to do.

[Ferdinand]

9 hours ago, joe90 said:

No mention of its construction or insulation method?

The Worcester Park one mentioned is Timber Frame.

 

https://www.yourlocalguardian.co.uk/news/17898759.worcester-park-fire-review-timber-framing-install-sprinklers-expert-says/

[scottishjohn]

On 29/07/2020 at 18:39, AliG said:

 

I think the regs are quite general and don't take different construction methods into account very well. Putting polyurethane inside all the interior walls of a building would mean that if a fire took hold the whole place was very likely to go. It is a very strange thing to do.

is that not why you fit fire stops 

they expand under heat and block off sections which then will self extinguish due to lack of air and cavity will not act like a chimney drawing in air to keep fire going

 this is where durisol and istoex and velox have an advantage -they don,t burn  and no cavity  to act like a chimney -no complicated fire stop arrangements either if rendered and hard plastering on inside

I just wonder how long before sprinklers systems become required for new builds

Edited July 30, 2020 by scottishjohn

[AliG]

On the outside walls yes.

 

I don't know if you watched the video, but they built the hotel rooms as prefabricated SIPS pods. So all the inside walls were made of OSB and polyurethane, it looks like it was then covered in plasterboard.

 

The just fills the interior of the building with combustible material. Hotel rooms are pretty small and full of soft furnishings. Once a fire took hold, there is so much stuff that burns well that it would soon get out of control. Sprinklers would be the obvious way to stop this happening and it is very surprising that a modern hotel didn't appear to have them. it is such an odd construction that the regs do not really cover it, but really anyone looking at it would surely think it was a fire risk. Clearly timber frame houses have plenty of combustible wood in them, but if there is any insulation inside the house it is usually mineral wool that doesn't burn and wood burns relatively slowly. I cannot think of a single sensible reason to put PIR inside internal walls, it provides almost no sound insulation and it is expensive.

 

[scottishjohn]

1 minute ago, AliG said:

sensible reason to put PIR inside internal walls,

its what lots of builders do -gets insulation up to spec in a thinner wall

rembrand builders is just opposite my garage and i see them delivering truck loads  of it to TF houses being built around the shire

[scottishjohn]

I know they use mgo board sips panels in some parts of the world --cos bugs don,.t eat them like osb  and is very rot resistant

 and that would be fireproof 

you can even get one side  mgo  and other in osb

[AliG]

56 minutes ago, scottishjohn said:

its what lots of builders do -gets insulation up to spec in a thinner wall

rembrand builders is just opposite my garage and i see them delivering truck loads  of it to TF houses being built around the shire

 

I think we are at crossed purposes here. The polyurethane I am talking about is in the interior partition walls. They don't need to be insulated. They used OSB SIPS inside the building for speed.

Edited July 30, 2020 by AliG

[Hobbiniho]

interesting to read the replies, as said they uses sips to speed up construction, essentially each room was a stand alone pod and then they were just stacked together and plugged in, it really makes me wonder as i have recently refurbed my house and i used PIR internally, it is suspected that the fire started in an upstairs linen room, and then spread quite rapidly to the roof

[scottishjohn]

10 hours ago, AliG said:

They used OSB SIPS inside the building for speed.

If it was just for speed then they could have made stud and osb  to make panels  to do just the same, only cheaper saving cost of insulation  and or filled them with mineral wool to give some fire protection  and sound deadening would still be cheaper I think