Fire protection of composite panel structures

Scotch Mist offers fire protection of composite panel structures.

The subject of composite or sandwich panels used for the construction of walls and ceilings within industrial premises continues to cause concern to building owners due to the reluctance of insurers to provide on-going cover for such premises.

Recent fire events have lead to the death of fire fighters due to structural collapse of composite panels and fire brigades are subsequently refusing to enter buildings in which these panels are known to exist.

Insurers often refuse to maintain cover without increasing premiums unless existing panels are replaced with the latest fire resistant types, which can be immensely expensive.

The alternative is pay the huge premiums now being demanded by insurers.

The option for new builds is relatively easy - install fire resistant panels.

However, what are the choices for existing premises? The ABI's Technical Briefing: Fire Performance of Sandwich Panel Systems makes a number of important recommendations aimed at new build but one piece of advice stands out for existing premises; Automatic fire suppression systems, appropriate for the process, should be fitted to all heating and cooking equipment.

This can be an attractive option where food-processing equipment is installed and even more attractive when a building is not fitted with a sprinkler system because the cost of installation of building sprinkler systems can be prohibitive.

Individual processor lines can be protected by water mist fire suppression systems that have the following advantages; * Water mist is a rapid, clean and efficient way to combat fires in machinery or machinery spaces.

* Selective protection can be provided allowing the minimum of disruption to occur in the event of a fire and minimising costly downtime periods.

* Water mist systems are clean to operate, use small amounts of water by comparison with sprinkler systems and require little or no clean up after activation.

* Water mist systems can protect an almost unlimited type of risk that neither sprinklers nor gaseous agents can combat.

* There are no expensive re-charge costs and systems can be put back into immediate service following a discharge.

* The retrospective installation of these systems is relatively easy, unobtrusive and not prohibitively expensive.

There is also indication that fire fighters will enter premises that contain composite panels once they are assured that individual risks are adequately protected and the risk of fire growth and structural collapse minimised.

The protection of equipment will in itself prevent many large fires but we have to consider what will happen in the event that fire breaks out as a result of some other source, rubbish piled close to a wall or a burning pallet, for instance.

In such instances, even a building sprinkler system may not prevent a damaged composite panel from catching light internally and spreading a devastating fire throughout the premises.

Appendix 'F' of Approved Document 'B' makes the point that the degradation of polymeric materials can be expected when exposed to radiated or conducted heat from a fire, which is most significant.

Fire encroaching upon a wall or ceiling constructed of sandwich panels may ignite the panels by radiation - without actually being in contact with the panels themselves - especially if there is panel damage or badly made or broken joints, which can occur with age and use.

Appendix 'F' goes on to say that most jointing or fixing systems for these systems have an extremely limited structural integrity performance in fire conditions.

If the fire starts to heat up the support fixings or structure to which they are attached, then there is a real chance of total collapse of the panel system.

As well as advocating suppression systems for both risks and enclosures, Approved Document 'B' provides significant advice, with the recommendation that preventing the core materials from becoming exposed to fire and by protecting the building superstructure, the stability of sandwich panel systems may be improved in the event of fire.

So, how can this be achieved without the need to install a building sprinkler system? Once again, this is where water mist comes into its own because systems are available that can protect walls and ceilings from encroaching flames during the growth of a fire and delay the point at which flashover occurs.

Scotch Mist is one such system and this has the following advantages over other systems;.

* Scotch Mist is extremely versatile and can be used to project its protective mist vertically or horizontally.

The protection of walls and ceilings is, therefore, easily within its capability.

* Scotch Mist can be configured to provide additional protection to panel joints and supporting structures.

* A single Scotch Mist system can be used to protect any number of individual risks without the expensive equipment needed to protect separate risks with separate equipment.

Although this method is likely to be less costly and disruptive overall than renewing existing panels in large premises, it should first be offered to the insurer as an alternative to higher premiums.

Some insurers accept innovative solutions, such as an engineered Scotch Mist system, to resolve situations that more conventional systems cannot protect and it is well worth discussing this as an option.

Any proposal to provide Scotch Mist composite panel protection should also be presented the local fire brigade and, if they give their approval for the system, they should once again offer full protection to the building concerned.

Some testing may be required, in which case the insurer may well offer funds to enable an actual-site scenario fire test to be set up and this cannot be refused.

Indeed, if the food industry were to get together as whole to initiate and fund application specific testing under the umbrella of the ABI, Scotch Mist composite panel protection could become standard procedure as the cost effective alternative to increased insurance premiums.

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