How long do fire doors protect you for?

There are different grades of fire door, and each one provides a different level of protection. The grades are separated by how long they can withstand fire. The main ones are FD30 (30 minutes), FD60 (60 minutes) FD90 (90 minutes) and FD120 (120 minutes).

Where are fire doors required?

All regulations pertaining to the use of fire doors are contained in Fire Safety: Approved Document B and following incorporations. According to the legislation, fire doors are required in domestic buildings over 2 storeys high; each door leading to a stairwell (at every level) from a habitable room (not a bathroom, for instance) must be a fire door. For commercial or non-domestic buildings, fire door requirements vary according to whether escape routes are vertical or horizontal (down stairs or through corridors).

Who enforces the Regulatory Fire and Safety Order?

The Regulatory Fire Safety Order is enforced primarily by the area’s local Fire and Rescue Authority (FRA). However, other organisations may enforce fire safety regulations in special circumstances, such as the Health and Safety Executive (HSE) or the Secretary of State for Defence’s fire service. If you are unsure as to where your FRA is based, you can either contact your nearest fire service or consult the National Fire Chief’s Council website.

What is fire protection?

The aim of a fire protection system is to safeguard a building’s occupants and minimise the damage associated with fire. Overall, the goal is to provide the widest possible window for a safe evacuation, whilst also reducing potential repair costs.\n\nFire protection systems can be categorised as either active or passive. While active systems are designed to detect and fight fires (such as fire alarms and sprinklers), passive fire protection describes the structural measures which prevent the passage of flames and smoke.

What is fire prevention?

Fire prevention systems are put in place so a building’s fire load is as low as it can possibly be. ‘Fire load’ is a term used by fire protection professionals to gage the potential severity of a fire in a building, based on the presence of certain hazards. Essentially, fire prevention reduces the likelihood of a serious fire. By safely storing combustible materials, and taking care of points of ignition (such as heating systems and plug sockets), we are reducing the risks associated with fire.

What is fire suppression?

The sole objective of a fire suppression system is to extinguish a fire as quickly as possible. \nOnce occupants are alerted to the presence of a fire, the system will begin to emit a concentrated substance to suppress the flames. The exact nature of this substance can vary, based on the environment the system is designed to protect. Common examples include carbon dioxide and inert gas, as well as a range of both liquid and dry chemical agents.

What is active fire protection?

Fire protection measures categorised as ‘active fire protection’ all react to action or motion. Fire alarms, for instance, must be activated to bring attention to a fire. Similarly, a fire extinguisher must be actively used in order to put out a fire. Fire sprinklers are also an example of active fire protection. This is because they are automatically activated in order to suppress a fire.

What is passive fire protection?

The term ‘passive fire protection’ describes structural measures implemented to prevent a fire from spreading within a building. Specialist contractors will be brought on as part of the building process to advise on passive fire protection measures, which can include compartmentation, firestopping and fireproofing using intumescent paint. According to Global Market Insights, the passive fire protection market is estimated to be worth $31 billion by 2026.

Why is concrete resistant to fire?

There are three main reasons why concrete has been categorised as one of the most fire-resistant materials; concrete is non-combustible, it’s non-toxic and it has low thermal conductivity. This means that it does not easily transfer thermal energy, and does not react easily with other substances (meaning that in the event of a fire there are no noxious gases released). This makes concrete one of the safest and most effective materials for structural fire protection.

What were the changes to building regulations after Grenfell?

The biggest change to building regulations post-Grenfell was a proposed ban on the use of combustible materials in the external walls of residential buildings over 18 metres in height.

Can a building collapse from fire?

A comprehensive enquiry into Grenfell Tower unearthed a chain of structural and maintenance failures leading up to the fire. A number of structural elements in a building can be damaged from fire, across a variety of temperatures and speeds. Therefore, a collapse can occur across multiple stages of severity. The most common cause of building collapse is damage to non-structural elements, which then increases the risk of structural exposure to fire. These elements include false chimneys, roof coverings, and windows.

What is the main objective of compartmentation?

One of the biggest risks in a fire is the spread of smoke and toxic gases. If not handled correctly, any attempt to evacuate a building will be hindered by the spread of smoke. Airflow between doors and rooms can push flames and smoke throughout a building. This is called the ‘chimney effect’. Compartmentation aims to mitigate this effect, controlling the spread for a prescribed period of time.

How does intumescent paint work?

The word ‘intumescent’ is derived from the Latin word “tumesco”, meaning expand or swell. Intumescent paints or sealants undergo an endothermic process, meaning the materials within the paints expand when exposed to high temperatures. Intumescent coatings are applied to steel frameworks in buildings, offering enhanced fire protection without affecting the steel’s mechanical properties. There are several ways to apply intumescent paint, the most common being spray-application as a film coating. Intumescent paint can be applied to steel, timber and an array of composite materials. Some varieties of intumescent paint can be given a decorative finish. In this instance, we would engage with the manufacturer to ensure that all the solutions we use are compatible with specific materials.

How much does intumescent paint expand?

The rate of expansion for intumescent paint depends on its thickness. Thin-film coatings will expand at a rate of 50:1, as a general rule of thumb. This means that a 1mm coating will reach an estimated density of 50mm in the event of a fire. Thick film coatings expand at an approximate rate of 5:1. It is worth mentioning that if a project intends to apply intumescent paint, then several aspects of the building should be designed to accommodate the rate of expansion.

How does a fire suppression system work?

A fire suppression system will have built-in components to detect fires as early as possible. These components will first identify the presence of flames and smoke. The suppression system will then initiate an alarm, so the blaze can be subdued before it has the chance to spread.

When is a fire suppression system required?

Fire suppression systems should be installed in buildings where a sprinkler system may not be the most effective method of fire protection. These can include rooms which contain a large amount of electrical equipment, or perishable items that could be susceptible to water damage. Although a fire suppression system is not legally required in the UK, property owners, be they commercial or residential, are responsible for carrying out fire risk assessments. This assessment, whether conducted internally or externally, may reveal the need for a fire suppression system. Further information can be found in our article on who exactly is responsible for fire safety legislation.

How does a fire suppression system work?

A fire suppression system will have built-in components to detect fires as early as possible. These components will first identify the presence of flames and smoke. The suppression system will then initiate an alarm, so the blaze can be subdued before it has the chance to spread. A fire suppression system can be considered an ‘active’ fire protection method because the system is triggered in response to the presence of fire. As will be explored further in this article, a fire suppression system also contains a range of components that ‘actively’ work to extinguish flames and smoke.

What is the difference between a fire sprinkler and a fire suppression system?

Both fire suppression systems and sprinkler systems can control or extinguish fires and are activated when detecting heat or smoke. A fire suppression system, however, doesn’t use water as it can be ineffective in certain types of fires. For example, a facility that uses combustible gas or oil, for instance, would not benefit from using water as a fire suppressing agent. For this reason, fire suppression systems are more common in industrial environments than traditional water sprinkler systems.

Why use an automatic suppression system?

Just like a traditional system, an automatic fire suppression system will consist of an element that detects heat and smoke and a suppression agent container. There will also often be a manual activation system that acts as a failsafe in the case that the automatic system isn’t triggered. The main benefit of an automatic fire suppression system is that they eliminate the need for human activation or intervention. Not only does this reduce the risk to occupants’ safety, but it is also ideal for extinguishing fires in remote or less accessible areas of a building or estate. Furthermore, automatic fire suppression systems are a particularly worthy investment for industries and companies containing flammable materials or high-value goods. This type of preventative measure could be looked upon favourably by insurance providers, who may reward business owners and landlords with lower premium rates for taking this type of precaution.

What are the risks of unsealed cavities?

A cavity is an enclosed space created by the design and positioning of a building’s structural elements. Common examples include gaps between walls, floors and ceiling voids. However, they do not include ducts, conduits, chutes, pipes, and other cavities that serve a distinct purpose. These cavities are often hidden, but they must be adequately sealed as part of a structural fire protection strategy. In the event of a fire, gaps between walls and floors can create ‘air buoyancy’, a push-and-pull effect caused by differences in air temperature. That can enable flames and smoke to quickly move between different areas of a building, otherwise known as the ‘chimney effect.’ Simply, these gaps allow heat, flames, gas, and smoke to travel unhindered from one building area to another. The upward flow of air, heat and flames creates significant challenges for fire safety in tall buildings. A fire that starts on the ground floor and moves up through empty cavities can accumulate on higher levels, with no place for hot air and smoke to escape. Therefore, cavities in a building must be appropriately sealed.

What is a cavity barrier?

Cavity barriers, also known as stop socks, work by blocking the passage of fire between cavities. They are made from either fire-resistant or intumescent materials (which expand in high temperatures to create a protective seal). By containing the spread of fire to a single area, they can reduce large-scale damage and create a window of time for a building to be safely evacuated and for firefighters to arrive.

What is the difference between a cavity barrier and a firestop?

The terms “cavity barrier” and “firestop” are often used interchangeably. While both are passive fire protection methods, there are a few key differences. As mentioned, a cavity barrier is a piece of fire-resistant material placed in enclosed, typically unused spaces within buildings. They are designed to prevent the spread of fire and hot gasses. In comparison, while firestops are also used to prevent the spread of flames and smoke, they typically come in the form of putty or intumescent clamps and are used to seal joints or gaps between pipes, conduits, or sockets and the walls through which they pass. It can also be used around fire doors, windows, and ceiling voids. That helps to maintain the fireproofing of a wall or floor by closing small yet still problematic gaps. In short, firestops seal any imperfections between building elements that should be fire-resistant.

A Guide to Fire Protection for Structural Steel

It is vital that as construction professionals, we understand how fire affects the behaviour of steel structures. A structural fire can exceed temperatures of 800°C or higher, depending on the severity of the conditions. Temperatures of around 550°C will cause a decline in the load-bearing properties of structural steel. The steel will lose its yield strength and buckle, causing it to bend, twist and ultimately collapse.

Unprotected steel frames can resist fire for approximately 15 minutes. According to industry fireproofing requirements for structural steel, this period of resistance must be increased substantially. The length of this period can vary, based on both the size and purpose of the building. For instance, an office over 30m high with sprinklers must have a minimum fire resistance period of 120 minutes.

According to data collected by Tata Steel, the majority of UK steel structures are protected in the following ways:

70% use intumescent paints
25% use fireproof boards
3-5% use firestopping sprays

These fireproofing methods can be broadly categorised in two ways: reactive and non-reactive. Intumescent paints are ‘reactive’ as they gain their fireproofing properties once exposed to extreme temperatures. Conversely, board fireproofing and firestopping sprays are non-reactive. This means that they contain firestopping properties regardless of temperature. In this article, we will outline how all of these methods ensure the compliant protection of structural steel.

Intumescent paint

Many structural fire protection strategies include intumescent paint for steel as a critical solution. Once applied, it expands into a solid, carbonaceous layer when subjected to temperatures of around 250°. This creates a protective coating around the steel to increase its fire resistance rating, which is usually either between 30, 60 and 90 mins. By increasing the period that the steel can withstand high temperatures, intumescent paint extends the window of opportunity for a building to be safely evacuated.

Intumescent paints can be applied by brush, roller, or spray. The application process can take place either on-site or off-site. On-site application is recommended if aesthetics are a priority, as well as short-term costs.

Intumescent film coatings

Intumescent coatings are the most widely-used method of structural steel protection in the United Kingdom. They contain materials that react to high temperatures. Once exposed to fire, the materials drastically increase in density. This provides an additional layer of protection to steel. Broadly speaking, intumescent coatings are available in two forms – thin film and thick film.

Thin film coatings

Thin film coatings are solvent or water-based and consist of a primer, basecoat and sealer code. They are usually the industry standard as they are suitable for buildings where fire resistance regulations (specified by Approved Document B) are either 30, 60 or 90 mins. In the event of a fire, thin film coatings can expand at a rate of approximately 50:1.

Thick film coatings

As their name suggests, what differentiates thick film and thin film coatings is that thick film coatings are much denser. They also have a lower expansion rate, a ratio of around 5:1. As they are a heavy-duty solution for protecting structural steel, they are usually used in industries that require working with extreme temperatures such as the petroleum industry. It’s also worth mentioning that in comparison to their less dense counterparts, thick film coatings are also often used in projects that require intumescent coatings to have a decorative finish.

Over recent years, technology and service innovation has allowed for more intumescent film coatings to be applied off-site. While this involves more upfront costs, specialists are able to uphold the highest possible quality control and compliance standards, making the installation process as a whole more efficient. Therefore, off-site installation is widely considered to be worth the initial investment.

Fireproof boards

In construction projects, practical constraints can lead to intumescent paint being less of a viable solution. These include project timescales, weather conditions, and potential accessibility issues. In these scenarios, fireproof boards can protect steel columns for up to 240 minutes, and steel beams for up to 180 minutes. These boards are made of rigid mineral-based wood and can be attached to metal beams, columns, and decking.

Fireproof boards are factory manufactured, so installers can rely on them to have a consistent weight and density. Broadly speaking, they will fall into one of two categories: lightweight or heavyweight. Lightweight boards will range between 150-250kg/m³ whereas heavyweight boards can weigh up to 950kg/m³. Aside from their weight, another distinguishing factor is that heavyweight boards are usually used in projects where aesthetic finish is a priority.

Fireproof boards offer a range of benefits for a passive fire protection project. As a ‘dry trade’, they can be installed quickly with minimal impact on other ongoing activities. For instance, in comparison to spray-applied fireproofing it is not necessary to have any tarping or ventilation around the construction areas. This can reduce costs and help streamline overall project delivery.

Cementitious coatings

Prior to the 1970s, cementitious fire protection was the primary way to safeguard structural steel from fire damage. This would involve coating steel beams and other elements in a combination of cement and gypsum. This coating is applied in layers, each one protecting the underlying materials. While cementitious coatings benefit from a high fire resistance rating, over the last few decades they have been superseded by solutions that are lighter and more versatile while offering a similar level of protection.

Firestopping sprays

Firestopping sprays are a simple and cost-effective fire protection solution for structural steel. These sprays can be either mineral-based (vermiculite being a common component) or made using low-density cement compounds. Firestopping sprays can range between 10mm and 70mm in thickness and are applied to steel using a spraying machine. As a rule of thumb, these sprays offer fire protection for up to 240 minutes.

Firestopping sprays are particularly beneficial in cases where aesthetics are not a priority. You can add an additional coating or a primer for aesthetic purposes, but this is not wholly necessary. If you opt for firestopping sprays, it is important to apply a binding layer of acrylic copolymer. An additional benefit to fire-stopping sprays is that they can increase sound absorption between walls and floors. Firestopping sprays have a range of applications, being suitable for not only steel but also wood, fabric, and composite-based materials.

CLM Fireproofing are one of the nation’s leading passive fire protection companies, specialising in a range of services including structural steel fireproofing. Our experienced team of passive fire protection specialists work with clients to deliver fire protection projects swiftly, efficiently and in full compliance with the latest industry regulations. Contact CLM Fireproofing to find out more.

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Understanding firestopping regulations in buildings

It is vital that as construction professionals, we understand how fire affects the behaviour of steel structures. A structural fire can exceed temperatures of 800°C or higher, depending on the...

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