Fire-rated sealants and mastics are designed to slow the spread of fire and smoke through joints, gaps and service penetrations, giving occupants more time to evacuate while protecting property from extensive damage.
A gap as small as the width of a pencil can allow smoke to fill an adjacent 20 x 20-foot room in less than four minutes, highlighting the importance of sealing even the smallest openings.
In this guide, we’ll explore the different types of fire-rated sealants, their applications and how they play a key role in maintaining building safety.
What are Fire-Rated Sealants?
In the event of a fire, fire-rated sealants either resist heat or expand to create a protective barrier, preventing flames, smoke and toxic gases from spreading.
They are commonly used to seal linear gaps and around service penetrations, such as pipes and cables, where gaps can act as pathways for fire and smoke. By sealing these areas, it maintains the structural integrity and compartmentation of a building.
These types of sealants provide strong adhesion to a wide range of surfaces, including wood, masonry and plasterboard, making them a versatile solution.
Common Applications of Fire-Rated Sealants
Fire-rated sealants can be used in many different applications to enhance fire protection and help maintain the integrity of fire-rated structures.
Linear joints
Applied to joints in walls, floors and ceilings to prevent fire and smoke from spreading through structural gaps, which are often the first points of vulnerability in a fire scenario.
Service penetrations
Used around pipes, ducts, cables and conduits, to seal any gaps created during installation, ensuring the integrity of the surrounding structure is maintained.
Perimeter sealing
Mastics around windows, doors and other openings help maintain continuous fire-rated barriers, protecting escape routes and ensuring occupants have a safer path to exit during an emergency.
Fire stopping systems
They are often integrated into broader fire stopping systems such as pipe collars, fire batts and air transfer grilles, as part of a tested solution.
Types of Fire-Rated Sealants
Fire-rated sealants and mastics are available in various formulations, each suited to different applications, and have fire resistance ratings ranging up to four hours depending on the product and installation.
Many of these offer acoustic sealing properties, helping to reduce sound transmission between rooms or compartments.
Understanding the different types of fire-rated sealants can help you choose the right product for your specific application.
Typically water-based, these expand when exposed to heat, forming a protective char that seals gaps and creates a barrier against flames and smoke. They are commonly used to reinstate the fire resistance of wall and floor constructions in linear gap seals, as well as around apertures penetrated by single or multiple services.
Typical applications: Service penetrations, linear joints, perimeter sealing, as part of a fire stopping system
Silicone-based products are generally non-intumescent but highly heat-resistant, flexible under extreme temperatures and are UV and weather resistant.
Typical applications: Static linear joints, perimeter sealing, service penetrations
Sometimes referred to as HPE, these provide maximum fire protection. Active components, such as graphite, expand significantly under heat, offering enhanced fire resistance in complex applications requiring long-lasting performance.
Typical applications: Service penetrations, linear joints, as part of a fire stopping system
Choosing the Right Fire-Rated Sealant
Specifying the correct sealant is essential for effective fire protection. Consider the type of penetration and the conditions it will face, such as moisture or potential joint movement. Always check the manufacturer’s datasheet to confirm suitability, installation requirements and fire performance.
When used as part of a passive fire protection system, it is crucial that the product matches the brand of all other components to provide a fully tested and certified solution. This avoids potential performance issues from mixing brands and ensures the system functions as intended. Find out more about the dangers of mixing brands in fire stopping systems.
How We Can Help
At FireSealsDirect, we stock the most trusted fire-rated sealant brands on the market, including FSi, Rockwool and Nullifire, all of which meet the most stringent British and EU regulatory standards.
Need help selecting the right fire protection products? Get in touch with our technical team at [email protected] or call 02920 857 959.
You can also explore our Advice Centre, which offers a wide range of guides and useful information on fire safety, fire legislation and more.
