Fire precautions to internal office pod

[Paul]

Not posted on here for some considerable time.

Hope someone can guide my thought process through this.  I am in the process of carrying out a FRA to a largish (10,000sqm) industrial baking factory.  The facility was originally a storage warehouse, with a small integral office to ground floor only.

The warehouse was then bought (1999 approx) and turned into an industrial baking factory (large gas fired ovens with complex series of flues etc), it appears that no change of purpose or indeed planning approval was applied for the internal fit out of the new bakery.

To add to this, the office facility was now taken to ground and first floor (2002), The construction of this new office facility is essentially a performed steel floor and supports, enclosed by polycarbonate sandwich white panels.  Production is also carried out directly under the offices where there is no fire resisting construction between this area and the 1st floor office area, and again non afforded to the structural steel work.

AFd throughout is to an L3 standard, although non under the offices within production area.  Around 30 person work on the 1st floor.  1 protected escape stair, and 1 external, each being in separate office areas of the 1st floor.

The whole of the internal office pod is surrounded by process equipment, plant (HVAC to roof of office).

Again, it would appear that planning was not applied for.  Having carried out the FRA I am concerned that no fire separation exists and that the currently no testing of the fire alarm takes place, therefore it is not known if it is operational.  Similarly, there are a number of plant rooms within this structure that do not afford Afd and as such it would be easy for fire to develop undiscovered for some time, by which time the panel structure would loose its structural strength.

The crunch question is, do I look at fire lining critical areas of the structure at considerable cost to the business?  Is it sufficient to upgrade the fire alarm system to P1, ensuring adequate testing is carried out and given that there are only ever a maximum of 30 persons occupying, robust EP etc etc.

I know it is difficult to picture by my description, but I would be interested where others would go with this?

Discuss?

[kurnal]

Sounds like an unprotected occupied mezzanine. Travel distances from the first floor to a protected route?

What exactly is the construction of the sandwich panels- EPS, PUR or PIR?

What are the processes going on beneath?

The protection to a mezzanine under the Building Regs is partly for protection of firefighters and partly for occupants. The Fire Safety Order does not consider firefighter safety. As building work is more than a year old you really only have to consider this from the point of view of relevant persons- but I would ensure the local brigade are advised to consider their operational tactics.

[Paul]

Hi Kurnal,

Difficult to tell really.  I think it is PIR, as no records are held.  I have taken sample of the core and it is compressed polystyrene balls (is this EPS?)  Set fire to it and it burn very well indeed!!

Processes going on underneath are low risk.  Mostley mixing and cutting of product.  The concern is the electrical and HVAC plant hidden away in small rooms, all part of the same pod though.

Travel distances are within 45 meters, although only just.

Company wants to fire line as they feel it is best practice.  I personally feel it is of little value.  Better to spend on P1 upgrade and robust fire safety management.

Understand about the 12 months post ABd etc, but what about from an insurance perspective.  I know insurers don't like these panels, especially as they are used extensivley in food process plants.  Do you think this will compromise the insurance as adequate fire seperation does not exist from the offices and the process areas?

Thanks Kurnal for your thoughts

[kurnal]

The panels are EPS - the worst kind. Lots of problems can arise with these- rapid combustion of the core, delamination and collapse of the panels, rapid fire spread unseen in the core. At least they are not used as a floor. That would be a problem. I suggest you look at EPIC,  http://www.epic.uk.com/   the trade organisation for these things, and they have loads of videos and freebies that explain the issues and give advice on how they should be considered in a fire risk assessment.

The scale of use and how they are installed and used really determines whether there is a problem or not. Certainly they should be brought to the attention of firefighters, and whilst they are commonplace in cold stores they would not be expected in a bakery.

Presumably the offices can be considered ancillary to the Bakery  (using definition in ADB). I would compare the construction to the ADB benchmark as part of the fire risk assessment. This is one situation where the Fire Safety Order guides will not contain sufficient information.  As an absolute minimum you should consider full AFD  under the floor and in rooms in lieu of the fire resisting construction supporting the floor. You may need to do more depending on the scale and installation of the EPS. The issue for the fire risk assessment is whether the polystyrene is likely to affect development of the fire in its earlier stages as the relevant persons make their escape.

[Paul]

Thanks for the info Kurnal.

Just incase anyone else would like this info, here is a link to the Guide prodcued on behalf of the DCLG, carriedout by TENOS and Warrington Fire Research.

http://www.epic.uk.com/assets/epic_rrfso_guide.pdf

Cheers

Paul