FIRE SAFETY - 22.09.2010

What’s a fire-resistant letterbox?

Fire starters

A recent survey by insurance company Aviva found that the single biggest cause of fires in commercial premises was arson. And arsonists love letterboxes - especially those which lead straight onto your lobby. They can push all sorts through, including flammable liquids, matches and fireworks. However, these fires can be stopped in their tracks by fitting a fire-resistant letterbox (see The next step).

How do they work?

The most robust versions of these products include a metal box which is designed to contain any flammable liquid. These incorporate a small fire extinguisher which is triggered automatically if exposed to heat. They can be fixed on the internal opening of your letterbox.

Tip. You can also buy boxes to mount externally on the wall. These arguably represent the most effective solution, as it means that your mail is protected from fire as well as avoiding the need for an opening into the building.

Note. Although some manufacturers sell these products as “fire proof”, there isn’t a 100% guarantee. “Fire resistant” is a better description.

Soft option

There are other versions available which use a soft mail bag that attaches on the inside of the letterbox. On one product we reviewed, the material includes an “intumescent” product which expands on exposure to heat, and is fire resistant. Another uses an automatic extinguisher in a similar way to the metal box designs.

These soft bags appear to deal with burning material being pushed through the letterbox but it seems unlikely that they would prevent flammable liquid from escaping onto the floor. However, they may be the only option if your door opens onto an internal wall, where there is minimal space to house a bulky metal letterbox.

Practicalities

The products range in price from £75 to £200, so they’re a bargain in relation to the cost and inconvenience of a fire.

Tip 1. The letterboxes can usually be easily installed by a handyman, so there should be little added expense.

Tip 2. Don’t confuse these products with the fire rated letter plates which are available. These are not products which will prevent an arson attack. They’re designed to be fitted into fire rated doors to maintain the level of fire resistance, e.g. if you needed to install a letter opening in an internal fire door.

Are there maintenance considerations?

There are minimal maintenance requirements. You may need to change the fire extinguisher periodically, depending on the manufacturer’s instructions. Also, as you’d expect, if the product is used in anger, you may find that you need to replace the whole thing.

For further information on fire-resistant letterboxes, visit http://healthandsafety.indicator.co.uk (HS 09.02.07).