Passive fire protection is essential in stopping the spread of fire. It decreases the damage to the building and equipment, gives more time for workers to escape, and makes it easy for the fire department to eliminate the danger. Cavity fire barriers and fire-stops are two ways to provide passive fire protection to your building.
However, due to the use of these terms interchangeably, you wonder whether they are the same. As they have different use cases, we’ll explain the dissimilarities to clarify this subject.
What are Cavity Fire Barriers?
First, let’s dive deeper into each passive fire protection tool as this helps differentiate between the two. Every building has several gaps in its design, like a wall with a door or parts of the construction where the walls or floors join. They are internal, which is why you won’t know they exist.
These cavities don’t have any purpose and pose a significant fire risk. When a fire breaks in a room, these gaps allow the smoke to escape. As a result, fresh air enters the room, fueling the fire. This is dangerous as the fire spreads uncontrollably, causes significant damage to the building, and puts the workers at risk.
Cavity fire barriers, like the AIM Wall Cavity Barrier, fill up these gaps to prevent fire from spreading throughout the building. It helps the building maintain its fire resistance by acting as a seal.
Generally, you install them during construction. However, older buildings built before stringent fireproofing regulations came into place may not have cavity fire barriers.
The role of cavity fire barriers is to contain the fire by compartmentalising your building’s construction. This is why they use materials that are intumescent or fire-resistant.
Where Do You Install Cavity Fire Barriers?
As we’ve highlighted earlier, they seal invisible gaps in the building. But where do these cavities occur in the building’s construction? Here’s a list of common areas where internal gaps exist:
- Floor and wall junction
- Compartment or interior wall junction
- Wall with door junction
- Door and window openings
- Extract vents
Before installing the cavity fire barriers, you also need to factor in:
- Expansion of building materials due to heat
- Changes in the building’s movement due to the presence of cavity fire barriers
- The lifespan of the building
They influence the cavity fire barrier’s effectiveness. If you’d like to learn more about installing cavity fire barriers, here’s a handy video from Rockwool.
What are Fire-Stops?
Similar to cavity fire barriers, the role of fire-stops is also to prevent fire from going out of control and containing its spread.
The main difference between the two is where you install them in the building. As highlighted earlier, cavity fire barriers are for internal gaps, i.e., you won’t see them.
However, there are visible imperfections in the building, especially between the wall and ceiling or holes in walls for wiring or piping. Also, these building elements must have a fire rating, i.e., fire resistance.
Even if you have fire-rated ceilings and walls, the lack of continuity between the two, allows the fire to grow due to the exchange of smoke and fresh air. With fire-stops, the ceilings, walls, and other elements keep their fire ratings intact, preventing the spread of fire.
Fire-stops, like the rockwool sp60, also use similar materials like intumescent or fire-resistant. Glass fibres and cement are common materials you’ll find in these products. However, this doesn’t mean you can use any material for your building. You must factor in the fire rating of the building’s elements, as the fire stops should also have a similar rating.
Where Do You Install Fire-Stops?
Now that you know what fire-stops do, we’ll now explain where you should install them. You can think of them as a way to ensure the continuity of various building elements’ fire ratings. We recommend you install them in the following areas.
- Any holes or penetrations in the fire-rated wall for service (electrical or mechanical) or structure-related.
- Fire-rated wall and floor junctions.
- Openings you’ll make for future electrical, mechanical, or structural reasons.
- Joints for Head-of-Wall (HOW)
Which One Do You Need – Cavity Fire Barriers or Fire-Stops?
We often get this question – does the building only need cavity fire barriers or fire-stops? The reality is that you will require both to improve the building’s passive fire resistance. Only opting for one means there’s the inherent risk of an incomplete seal in the structure, decreasing fire resistance.
The best way to understand what your building requires is to contact professionals that are experts in passive fire resistance, like Galaxy Insulation and Dry Fitting. This way, you’ll know the weakness or gaps in your building’s construction and how to rectify them, reducing fire risk significantly.
Key Differences Between Cavity Fire Barrier and Fire-Stop
| Feature | Cavity Fire Barrier | Fire-Stop |
| Function | Seal invisible gaps | Seal visible gaps |
| Location | Junctions between wall and floor, door and wall, windows, and extract vents. Extract ventsOpenings in windows or doors. | Penetrations for service components or structural reasonsJunctions between wall and floor (fire-rated) or head-of-wall.Future openings or penetrations in the wall |
| Factors for installation | Movement changes it introduces to the building.Building’s lifespanThermal expansion of various building materials. | Should be similar to the fire rating of the wall, floor, or other building elements. |
Final Thoughts
Although cavity fire barriers and fire-stops look similar, they have different functions. Cavity fire barriers seal the internal gaps in the structure, while fire-stops are for visible, unprotected openings within the building.
If you’re looking for durable and quality cavity fire barriers or fire-stops from leading manufacturers in the UK, contact Galaxy Insulation and Dry Fitting. We can help you source the right fireproof elements, depending on your building’s requirements.
Author Bio
Cinthia Rosa
As the marketing head at Galaxy Insulation and Dry Lining in the UK, Cinthia Rosa has a reputed name in the industry. She consistently contributes her valuable knowledge to top blogging sites.
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