Passive Vs Active Fire Protection

Posted Friday, 3rd July 2020

You might be wondering, what is the difference between Passive & Active fire protection? And which is more important? This week’s blog post is to help clear up those questions up for you and enable you to understand the importance of both. Firstly, lets understand the difference between the two. Passive fire protection breaks the building into “compartments” and prevents the spread of fire through the use of fire-resistance rated walls and floors.

The use of fire doors is also involved to help further compartmentalization the structure and dampers to prevent the spread of fire and smoke throughout the ducts of the building. On the other hand, Active fire protection focuses on the need of some kind of action to stop a fire. Some of these systems are automatic, like sprinkler systems, and others are manual, like fire extinguishers. Fire alarms and smoke detectors, are all considered Active fire protection systems. In Active fire protection, there are a few different categories;

1. Detection

   mostly takes place using sensors that detect heat, smoke, or flames and send a signal to alarm the occupants of the building.

2. Suppression

   anything that can put out a fire through direct action either manually, such as fire extinguishers, or automatically with indirect or direct release systems.

3. Ventilation

   keeping evacuation routes smoke free with fire-resistant fans.

Active Fire Protection Systems

Fire/smoke alarm systems

Fire/smoke alarms are self-contained devices that are used to detect fires and alarm the occupants of a fire in its first stages. For alarms to be effective, it is important that they are positioned as close to the centre of the room as possible, but where they can be heard throughout a building, should they be activated in the event of a fire. The more you have in a building, the more chance you have of vacating the property in enough time and alert the emergency services.

Sprinkler Systems

Fire sprinkler systems can significantly reduce the risk to life and mitigate the damage caused by fire. An automatic system is designed to detect a fire and extinguish it in its early stages or hold the fire for as long as possible so that extinguishment can be carried out by other means.

Fire Extinguishers

There are five main types of fire extinguishers, all of which are effective on different kinds of fires. Before installing and using fire extinguishers, it is important to understand their different uses and which will be most effective.

• Water

  Water extinguishers are the most common fire extinguisher type for class A fire risk. Most premises will require either water or foam extinguishers. Water extinguishes are most effective on fires caused by paper/cardboard, fabric and textiles or wood and coal. Water extinguishes have a cooling effect on the fuel causing them to burn much slower and eventually eliminate the fire.

• Foam

  Foam extinguishers are most common type of fire extinguisher for Class B fires, but also work on Class A fires as they are water-based. Foam extinguishers are effective on the same materials as water extinguishers, plus flammable liquids like paint or petrol.

• Dry Powder

  Standard dry powder extinguishers are also called 'ABC' extinguishers because they tackle class A, B and C fires, however they are not recommended for use in enclosed spaces. This is because the powder can be easily inhaled, and also the residue is very difficult to clean up after. ABC powder extinguishers can also be used on some electrical fires. Specialist dry powder extinguishers are used for flammable metals.

• Carbon Dioxide (CO2)

  CO2 extinguishers are mainly used for electrical fires and are usually the main fire extinguisher type provided in computer server rooms. They also put out Class B fires (flammable liquids, such as paint and fuel).

• Wet Chemical

  Wet chemical extinguishers are designed for use on Class F fires, involving cooking oils and fats. They can also be used on Class A fires although it is more common to have a foam or water extinguisher for this type of fire risk.

Passive Fire Protection

Passive fire protection is a vital factor of any fire safety strategy. It is built into the structure of a building to safeguard people’s lives and limit the financial impact of damage to buildings and their contents. This is done by;

• Limiting the spread of fire and smoke by containing it in a single compartment
• Protecting escape routes for essential means of escape
• Protecting the building structure thus ensuring it’s sustainability

Fire Stopping

Fire Stopping. Where services pass through fire compartment walls, the aperture must be sealed with ‘approved products’ that have been tested to BS 476: Pt. 20/22: 1987. The most common and versatile of such products is Fire batt and Intumescent Mastic. All combustible services are to be sealed with either graphite mastic, an intumescent wrap or an intumescent collar. With such materials, a fire rating of up to 4hrs can be achieved.

Cavity Barriers

Cavity Barriers or “Fire Barrier”, can be used to create compartmentation in roof/loft voids and above ceiling grids. Achieving a fire rating of up to 4hrs and being very versatile, it can be used to create both small and large barriers.

Beam Clad

Steel Structures can have their Fire Rating upgraded with this highly versatile, Class A1 and Class 0, gypsum board, suitable for constructing all forms of partition and ceilings, including curved applications, giving high-levels of fire and impact protection.

Slab Edge Fire Protection

Designed to form cavity fire stops within buildings, can be installed horizontally or vertically and is suitable for cavity widths between both masonry and curtain wall constructions. Resists the passage of smoke and is easy to install. A fire rating of up to 4hrs can be achieved.

Fire Doors

Fire Doors form part of a Passive Fire Protection system. They reduce the spread of fire and smoke between separate compartments of a structure and to enable safe egress from a building or structure. It is essential that periodic checks are carried out every 6 months on Fire Doors. Only trained and competent persons should carry out these checks. BDL offer Inspections, Maintenance and Replacement Fire Doorsets.

All fire doors must be installed with the appropriate fire-resistant fittings, such as the frame and door hardware, for it to fully comply with any fire regulations. At BDL, we offer Inspections, Maintenance and Replacement Fire Doorsets.

Wrapping Up

Each year, fires affect thousands of businesses across the UK. Resulting in injury, lost customers, buildings and ultimately lives. As a business owner, it is your duty (and it’s also the law) that you protection your building and the people in it. Be installing some of the elements above, and assessing your current situation in regards to fire safety, you could save yourself thousands and more importantly, protect the safety of your staff and the surrounding public.