Brick veneer, a popular choice for both structural and aesthetic purposes in building construction, has been the subject of extensive assessment and testing to determine it’s compatibility with fire safety regulations. One such assessment report, FAR 2487 conducted by BRANZ, has concluded that a brick veneer with a thickness of 70 mm can replace one lining of a steel or timber framed plasterboard wall without compromising the wall's tested or assessed FRR (Fire Resistance Rating) up to 60/60/60. This finding holds true for fires originating from both the brick veneer face and the plasterboard lined face, providing reassurance regarding the durability and fire safety capabilities of brick veneer as a building material.
What Is the Fire Rating of a Brick Veneer Wall?
The fire rating of a brick veneer wall is an essential consideration when it comes to building safety. Depending on the thickness of the adhered brick veneer, the fire resistance of the wall can vary significantly.
This additional hour of fire resistance provides even more time for occupants to evacuate a building safely and for firefighters to conduct their operations effectively.
However, it doesn’t necessarily mean that the wall remains intact and unaffected by fire during this time. The ability of the veneer to resist structural failure and maintain it’s integrity under fire conditions is a vital consideration in building design and construction.
These regulations aim to ensure adequate fire safety measures and protect the lives of occupants.
The Factors That Influence the Fire Rating of a Brick Veneer Wall, Such as the Type and Thickness of the Materials Used.
The fire rating of a brick veneer wall is determined by various factors, including the type and thickness of the materials used. These factors affect the wall’s ability to resist fire and prevent it’s spread. It’s important to choose materials that have been tested and certified for their fire resistance properties. Thicker materials generally offer better fire protection, as they provide more insulation and slow down the spread of fire. Additionally, certain types of bricks, such as those made from clay or concrete, tend to have higher fire ratings compared to other materials. Overall, the selection of materials and their thickness are key considerations in determining the fire rating of a brick veneer wall.
Masonry veneers, which are used for decorative facing purposes, come in various sizes and materials such as concrete or clay facing brick, split, fluted, glazed, ground face or scored block, and stone veneer. Stone veneer, in particular, is a thin layer of stone used for decorative purposes and isn’t meant to bear loads. These veneers are typically 4 inches (102 mm) thick, but there are also options available in 3 inches (76 mm).
What Size Are Masonry Veneers?
Masonry veneers come in various sizes and are often composed of different architectural units. These units can include concrete or clay facing brick, split, fluted, glazed, ground face, scored block, or stone veneer. Stone veneer, in particular, is a thin layer of any stone used as a decorative facing material that isn’t load-bearing. It’s often applied to buildings or structures made of materials other than stone, making it a popular choice for adding a touch of elegance and sophistication.
The thickness of anchored masonry veneers is typically around 4 inches (102 mm), but it isn’t uncommon to find 3-inch (76 mm) veneer units available as well. This variety in thickness allows for flexibility in design and ensures that masonry veneers can be easily adapted to different architectural styles and requirements.
For example, facing bricks are typically larger in size compared to split or fluted blocks. This allows for greater ease in installation and can result in a more visually appealing finished product.
Unlike full veneer brick walls, which are typically 4-5 inches thick, thin veneer brick walls are much thinner, ranging from 3/4″ to 1 1/4″ thick. Additionally, thin veneer is much lighter in weight, accounting for only about 25% of the weight of full veneer. The installation of thin veneer doesn’t usually require a brick ledge and can be applied to nearly any wall, as long as proper preparations have been made.
What Size Are Brick Veneer Walls?
Brick veneer walls come in varying sizes depending on the type of veneer being used. The most common types are Thin Veneer and Full Veneer. Thin Veneer is generally around 3/4″ – 1 1/4″ thick, while Full Veneer is much thicker at 4-5″. This significant difference in thickness also affects the weight of the two types. Thin Veneer is approximately 25% of the weight of Full Veneer.
One advantage of Thin Veneer is that it doesn’t require a Brick Ledge during installation. This makes it a versatile option as it can be applied to almost any type of wall, provided it’s properly prepared beforehand. It’s important to ensure that the walls surface is clean, flat, and structurally sound before applying the Thin Veneer.
Full Veneer, on the other hand, is heavier and requires a stable support structure, as well as a Brick Ledge, to ensure proper installation. The thicker profile and increased weight of Full Veneer make it a durable option, ideal for exterior walls. It provides added insulation and strength to the overall structure.
Pros and Cons of Brick Veneer Walls
- Pros of brick veneer walls:
- Enhanced aesthetic appeal
- Lower cost compared to solid brick walls
- Improved insulation and energy efficiency
- Easy installation process
- Reduced maintenance requirements
- Flexible design options
- Cons of brick veneer walls:
- Potential for moisture problems if not properly installed
- May require additional insulation to meet energy efficiency standards
- Less structural strength compared to solid brick walls
- Not suitable for load-bearing applications
- Potential for damage from impacts or extreme weather conditions
- Limited lifespan compared to solid brick walls
Now let’s take a closer look at what each criterion represents and how the 60/60/60 fire rating is determined.
What Does 60 60 60 Fire Rated Wall Mean?
The 60/60/60 fire rated wall refers to the fire resistance level of a building element. In fire safety engineering, it’s important to assess the ability of various structures within a building to withstand fire for a specific duration. The FRL 60/60/60 denotes that the building element has been tested and proven to resist fire for 60 minutes in each of the three criteria.
The three criteria generally evaluated in fire resistance tests are structural adequacy, integrity, and insulation. Structural adequacy refers to the ability of the element to maintain it’s load-bearing capacity during a fire. Integrity determines the ability of the element to prevent the passage of flames and hot gases. Insulation measures the ability of the element to limit the transmission of heat to the unexposed side.
This rating indicates that the element will remain structurally sound, maintain it’s integrity, and provide insulation for an hour in the event of a standard fire.
It’s crucial to consider fire resistance ratings when designing and constructing buildings, especially in areas where fire safety regulations are strict. The 60/60/60 rating ensures that the building element will provide sufficient protection against fire for a significant period, allowing occupants to evacuate safely and giving firefighters ample time to mitigate the blaze.
To achieve a 60/60/60 fire rating, specific materials and construction techniques must be followed. The building element needs to be constructed using fire-resistant materials such as fire-rated gypsum board, fireproof insulation, and intumescent coatings. Adequate fire stopping measures and joint systems also contribute to maintaining the required fire rating.
It guarantees a substantial duration of protection against fire-related hazards, allowing for effective evacuation and firefighting efforts. Architects, engineers, and builders utilize this rating to ensure the safety and longevity of structures in the face of fire emergencies.
When constructing a brick veneer wall, it’s crucial to include a one-inch space between the veneer and the structural wall behind it. The reason for this requirement is twofold. Firstly, this space allows for the use of a mortar collection device, preventing excess mortar from clogging the weep holes at the bottom of the veneer. Secondly, it facilitates air movement within the airspace, particularly when the top of the veneer is open behind a soffit or fascia that’s vents placed at the top. This airflow helps prevent moisture buildup and promotes the overall longevity of the brick veneer wall.
Why Is a 1 Space Required in a Brick Veneer Wall?
One of the key reasons why a one-inch space is required in a brick veneer wall is to accommodate the use of a mortar collection device. This gap allows for any excess mortar to be collected and prevents it from blocking the weep holes at the base of the veneer. These weep holes serve as drainage points that prevent water from accumulating behind the brick veneer, which could potentially lead to moisture-related issues such as mold or rot.
Additionally, the one-inch space in a brick veneer wall provides an avenue for air movement within the airspace. This is particularly important when the top of the veneer is open behind a soffit or fascia that’s vents placed at the top. The movement of air can help promote ventilation, allowing moisture to evaporate and helping to maintain a dry and healthy environment behind the veneer.
Furthermore, this space also provides flexibility in the expansion and contraction of the brick veneer due to temperature changes. By allowing for some movement, the risk of cracks or damage to the veneer is minimized.
It facilitates the use of a mortar collection device, promotes air movement and ventilation, allows for expansion and contraction, and aids in drainage. These benefits collectively ensure the long-term durability and performance of the brick veneer system, preventing common issues associated with moisture accumulation and structural damage.
Source: Is There A Minimum Airspace Behind A Veneer?
Conclusion
These findings assure us that incorporating brick veneer into our construction processes poses no significant risks to the structural integrity and fire safety of the building.