Wall Ties or Brick Ties in Construction

Wall ties or brick ties are strips or bars made of metal that are used to connect or join the two leaves of a cavity wall together. These ties permit the two units of a cavity wall unit to act as a homogeneous unit. 

Wall ties or brick ties are installed in such a way that, they are hidden within the wall, without compromising the overall stability of the building structure. 

The features and types of wall ties used in masonry wall construction are explained in this article.

Features of Brick Wall Ties

Brick wall ties have been used since the 1850s for loadbearing masonry, cavity walls, and brick veneer construction. From the period, these metal ties were used in empirical sizes, shapes, and types. In the United States, metal ties proved to be more water-resistant and well-bonded masonry wall structures.

The use of metal wall ties are a standard bricklaying practice in the UK since the early 20th century.

Wall ties are commonly made of steel and traditional iron. In order to prevent corrosion, they are coated galvanized. Stainless steel ties are used to limit the risk of exposure to ties to water and chemical attack from cement.

Function of Brick Wall Ties

The main functions of brick wall ties are:

1. To provide a connection between the wall units
2. To transfer loads
3. To permit in-plane movements to accommodate differential movements. In certain situations, restrain lateral movements.
4. To act as structural reinforcement for longitudinal continuity.

Requirements of a Wall Tie

To perform the above-mentioned functions in brick masonry, a wall tie must possess minimum requirements and quality. The basic requirements of wall ties that are used for brick masonry construction are:

1. The wall ties must be installed and attached securely to both the masonry wall units.
2. The type of wall ties used must have sufficient stiffness to transfer the lateral loads by undergoing minimum deformations.
3. Minimum amount of mechanical play is required by the wall ties
4. Wall ties must be corrosion resistant
5. The installation must be easy to reduce related errors and damages to the tie system
6. The tie length must be long enough to span the cavity or the wall unit to provide minimum embedment in the mortar at both ends. The length of wall ties typically ranges between 62 and 75 mm.
7. As per Eurocode, the minimum density of cavity wall ties is 2.5 ties per square meter of wall.

Also Read: Types of Bonds in Masonry Construction