How Far Apart Should Wall Ties Be Placed
The spacing of wall ties in a cavity wall should be determined based on several factors.
For walls with a cavity wider than 175mm, the length of the wall ties should be calculated as the nominal cavity width plus 125mm, and the nearest stock length should be selected.
In general, for cavity walls where both leaves are 90mm or thicker, a minimum of 2.5 wall ties per square meter is recommended.
The maximum horizontal spacing for wall ties is 900mm, and the maximum vertical spacing is 450mm, although this may vary depending on Building Regulations.
The ties should be evenly distributed over the wall area in a staggered pattern, except around openings.
Around openings, such as windows and doors, the vertical spacing is reduced to a maximum of 300mm, and ties should be no more than 225mm from the edge of the opening.
Different considerations apply for timber frame and cold-formed steel frame construction.
Timber frame ties should be flexible enough to accommodate seasonal shrinkage and expansion, with specific allowances for frame shrinkage depending on the tie type.
The minimum density for timber frame ties is 4.4 ties per square meter, increasing to 7 ties per square meter in more severe situations.
Cold-formed steel frames require the use of the 25/14 restraint system, with specific maximum spacing guidelines for the channels and wall ties.
In conclusion, the spacing of wall ties should be determined based on cavity width, wall thickness, and the type of construction being used.
Did You Know?
1. The distance at which wall ties should be placed depends on several factors, but on average, they are typically spaced around 16 to 32 inches apart horizontally and vertically.
2. Wall ties play a crucial role in stabilizing masonry walls, especially in high-rise buildings. They provide structural support and help distribute the load evenly across the wall.
3. The Romans were early pioneers in the use of wall ties. They used iron wall ties known as “hare’s foot” to connect the outer and inner walls of their structures, increasing stability and durability.
4. In modern construction, wall ties are commonly made of corrosion-resistant materials such as stainless steel or galvanized steel to prevent rust and ensure long-lasting performance.
5. Interestingly, wall ties are not just limited to vertical applications. In some cases, they are also used horizontally to connect masonry walls to concrete or steel beams, providing additional reinforcement and enhancing structural integrity.
Common Problems With Wall Ties
Cavity wall ties play a crucial role in maintaining the stability and integrity of a building’s exterior wall. However, there are several common issues associated with wall ties that need to be addressed for optimal performance.
One such problem is the lack of sufficient embedment in the mortar joint. It is essential to ensure that wall ties are embedded at least 62.5mm deep to provide adequate strength and stability.
Another common issue is the use of incorrect tie specification. Depending on the construction materials and width of the cavity, different types and lengths of wall ties may be required. Using the wrong type or length can compromise the structural stability of the building.
Insufficient quantity of wall ties is also a concern. As per the Building Regulations, a minimum of 2.5 wall ties per square meter is required for cavity walls with both leaves measuring 90mm or more. Inadequate tie quantity can increase the risk of movement and instability within the structure.
To tackle these problems, Ancon offers a range of remedial wall ties designed for retrofit installation. These ties can be added to existing structures to enhance stability and address issues such as insufficient embedment, incorrect tie specification, and inadequate quantity. By installing remedial wall ties, the structural integrity of the building can be effectively improved.
Remedial Wall Ties For Retrofit Installation
Ancon offers a range of remedial wall ties that are specifically designed for retrofitting in existing structures. These ties are installed after the construction process to reinforce the stability of the outer leaf of the cavity wall.
Retrofitting wall ties can address common issues such as insufficient embedment, incorrect specification, and insufficient quantity. This solution effectively improves the structural stability and overall integrity of the building.
When planning to install remedial wall ties, it is crucial to seek the guidance of a professional engineer or contractor. They will assess the specific requirements of the structure and determine the appropriate type, length, and quantity of ties needed for the retrofit installation.
Determining The Length Of Wall Ties
The length of wall ties needed for a particular construction project depends on the width of the cavity. The Building Regulations provide guidance on the required lengths of wall ties in Table 5 of Approved Document A.
For cavities wider than 175mm, the length of the wall tie should be calculated as the nominal cavity width plus 125mm, and the nearest stock length should be selected. This ensures that the wall tie can adequately span the width of the cavity and provide the necessary stability.
Properly determining the length of wall ties is crucial to ensure that they are effective in enhancing the structural stability of the building. It is essential to follow the guidelines specified in the Building Regulations and consult with professionals to ensure the correct lengths are selected.
• The length of wall ties should be calculated based on the width of the cavity.
• For cavities wider than 175mm, the nominal cavity width plus 125mm is the recommended length.
• Consult professionals and follow Building Regulations for accurate wall tie length selection.
“Properly determining the length of wall ties is crucial to ensure that they are effective in enhancing the structural stability of the building.”
Proper Distribution And Spacing Of Wall Ties
To ensure optimal structural stability, wall ties should be evenly distributed over the wall area in a staggered pattern. This distribution helps to evenly distribute the loads and forces throughout the wall, reducing the risk of movement and instability.
The maximum horizontal spacing for wall ties is typically 900mm, while the maximum vertical spacing is 450mm. However, it is important to note that these values may vary based on specific Building Regulations.
Around openings such as windows and doors, the vertical spacing of wall ties should be reduced to a maximum of 300mm. Additionally, ties should be positioned no more than 225mm from the edge of the opening. This closer spacing ensures that the openings are adequately supported and reinforced.
Proper distribution and spacing of wall ties is crucial to ensure the structural stability of the building.
By following the recommended guidelines and regulations, potential issues related to uneven load distribution and insufficient support around openings can be mitigated.
- Wall ties should be evenly distributed in a staggered pattern.
- Maximum horizontal spacing for wall ties is typically 900mm.
- Maximum vertical spacing is typically 450mm, although this may vary based on Building Regulations.
- Around openings, vertical spacing should be reduced to a maximum of 300mm.
- Wall ties should be positioned no more than 225mm from the edge of the opening.
Wall Tie Specifications For Timber Frame And Cold-Formed Steel Frames
When considering timber frame and cold-formed steel frames, it is important to select proper wall tie specifications that accommodate the unique characteristics of these constructions.
For timber frame ties, it is crucial to choose ties that are flexible enough to cope with the seasonal shrinkage and expansion of timber frames. Tie types 5 and 6 allow for up to 24mm of frame shrinkage, while type 7 allows for up to 65mm. These flexible ties ensure that the structural stability of the timber frame is maintained even during varying environmental conditions.
The recommended density of timber frame ties is a minimum of 4.4 ties per square meter, increasing to 7 ties per square meter in more severe situations. This higher density provides additional support and stability to the timber frame structure.
For cold-formed steel frames, Ancon’s 25/14 restraint system is recommended. This system involves placing vertical channels at stud positions to serve as fixing points for wall ties. The maximum horizontal spacing for the 25/14 restraint system is 600mm, and the maximum vertical spacing for wall ties and fixing screws is 450mm.
By adhering to these specific wall tie specifications for timber frame and cold-formed steel frames, the structural stability and integrity of these constructions can be effectively maintained. It is crucial to consult with professionals to ensure the appropriate tie types, densities, and spacing are selected for these specific building systems.
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Frequently Asked Questions
What is the spacing for wall ties per square metre?
The spacing for wall ties per square metre is recommended to be at least 2.5, with a horizontal and vertical center measurement of 900mm and 450mm respectively. It is important to note that this spacing can be adjusted as needed in accordance with the Building Regulations.
What is the spacing for block ties?
To ensure the stability and strength of the blocks, it is recommended to use a staggered spacing pattern for block ties. Typically, these ties are placed at a vertical spacing of 450mm and a horizontal spacing of 900mm. This arrangement helps distribute the load evenly across the wall, reinforcing its structural integrity. By strategically positioning the ties in this pattern, the blocks can withstand various external forces and maintain their stability over time.
How do you calculate wall ties?
To calculate wall ties, you need to determine the total wall space and the number of openings, such as windows or doors, in order to estimate the quantity required. Using the guideline of 2.5 wall ties per square meter, you can calculate the number of wall ties needed by multiplying the total wall space by 2.5. This method ensures an accurate estimate of the required wall ties for replacement, allowing for a more precise calculation of costs.
What are the standard wall ties?
Standard wall ties are essential components in building construction, specifically for connecting brick-to-brick or masonry-to-masonry. Typically crafted from durable stainless steel, these ties are designed to withstand the test of time when properly installed. By securely fastening the walls together, these standard wall ties ensure the structural integrity of the building throughout its lifespan.