Wall ties, sometimes referred to as "brick ties", are an important component of cavity wall construction. They provide an additional support to ensure the safety and stability of the entire structure. There are many types of wall ties, such as Butterfly Wall Ties, Type 1 Wall Ties, and so on.
Wall ties are metal bars or rods that span the entire wall cavity. They are typically used to join two parts of a cavity wall together to make a solid unit.
Prior to 1978, they were manufactured from galvanized steel and were initially thought to hold up over the life of the building. Recently, however, it has been discovered that these types of wall ties can corrode in as little as 15 years. Modern wall ties are primarily made of stainless steel. This durable material can resist corrosion from water and cement without the need for a protective coating. They are low maintenance and are manufactured separately to reduce material waste.
Hollow wall ties fail either due to construction and installation problems with the ties or due to long-term corrosion.
The cause of hollow wall tie failure can be a construction defect, or not being installed in the first place. It can also come from spacing the wall ties incorrectly, fixing or using those that are too short. Poor quality mortar may have been used that does not provide a strong enough bond for the ties.
Corrosion of wall ties.
Historically, wall ties were made of mild steel that had a galvanized coating or were painted. These coatings did not last, leaving the steel exposed and allowing it to corrode. The expansion caused by corrosion separated the bricks above and below the bed joints where the wall ties were laid. This leads to horizontal cracks that compromise the load-sharing capacity of the wall structure.
Raised bricks, raised roofs or wall cracks can all be signs of damaged wall ties and require expert tools and knowledge to assess whether it is a wall tie problem or some other structural failure. In addition, there are some types of butterfly and wire wall ties that may rust without any external signs of a problem. The only way to check these is by exposure or fluoroscopy.
1. Mechanical Ties (which work by expansion)
2. Resin bonded or grouted ties (non-expansive and usually a combined mechanical and adhesive fix)
3. Friction fix and screw in types (particularly suitable for timber and concrete/clinker blockwork)
4. Grouted sock anchors (for hollow units) and,
5. Specialised 'starter' type ties for installation into exposed walls prior to building another leaf to form a cavity.
For more information and help. Smart Craftsmen is your best choose. Contact us today to learn more about our wall ties options, and start experiencing their unique benefits.