Guide to Fire Retardants and Intumescent
There is a lot of information out there when it comes to what we need to do to prevent accidental fires in our buildings. So, here we have created our handy guide to help with the confusion of fire retardants and intumescent, what they should be used with and why they should be used!
What is a Fire Retardant?
The term fire retardant refers to a group of various chemicals which are added into manufactured and combustible materials such as textiles, plastic, surface finishes and coatings such as paint. The name itself refers to a function, as opposed to naming a specific group of chemicals.
Why Do You Need a Fire Retardant?
In this day and age, there are more combustible electricals and technology around in buildings and homes, which means there are more fire hazards. Not only that, we are in a period where consumerism is at an all-time high, meaning those scatter cushions and rugged blankets are only one spark away from sparking up the whole place.
In terms of technology, the hazard might not be entirely what you think. Sure, electrical appliances can malfunction and cause fires, but it is also down to the installation of the appliances. Every service that is installed in a building, such as electrical sockets, lighting units and water pipes can compromise the fire resistance of a room. This is because installation creates openings in its walls, floor or ceiling. Using a fire retardant on your building and surfaces can give extra peace of mind when it comes to protecting your building from fire accidents.
How Do Fire Retardants Work?
Fire retardants work by stopping or slowing the spread of fire. Fire-resistant or intumescent paints and varnishes will create a barrier against fire. They do this by forming a foaming char layer above substrates such as timber, steel or plaster. Chemicals within the coating react to heat by creating bubbles of inert gas, which are strengthened by both the paints own polymer and additives. This non-combustible meringue type layer insulates the substrate and increases the time it takes for the fire to penetrate through. In the case of steelwork, this insulation keeps the metal cool for longer, extending the time it takes to collapse.
Intumescent paints are usually rated by time (i.e. 30, 60 or 90-minutes resistance). It is often thought that these timings mean the coatings protect the substrate for that specified time, but this is not the case. The time given is actually the time it takes for the paint and substrate to fail (i.e. for fire to go through a treated door).
What is an Intumescent
(Fire Resistant) and How Does it Work?
An intumescent material is any a kind of substance that swells as a result of heat exposure, which leads to it increasing in volume, and decreasing in density. It is a core component of passive fire protection. Neither of the above should be mistaken for heat resistant paint, which is used on surfaces subject to high temperatures (such as stoves).
Although these paints resist high temperatures, they offer no protection against fire. They will be inherently fire retardant (because they don’t ignite when subject to a flame), but they don’t make the substrate fire retardant. They will also be inherently fire resistant (again because they don’t themselves catch fire), but they don’t confer fire resistance to the substrate (they won’t, for instance, prevent the underlying substrate from reaching its auto-ignition temperature). Heat resistant paints simply won’t degrade when subject to elevated temperatures.
Fire retardants will reduce the combustibility of vulnerable substrates (like wood) and slow the rate of fire spread. Fire-resistant or intumescent paints will offer an insulating barrier to fire, protecting substrates, allowing them to maintain their integrity for longer (for instance structural steelwork), or increasing the time it takes for a fire to break through a barrier (a fire door or wall). Heat resistant paints don’t decompose when subjected to high temperatures but offer no insulating qualities.