What is wall tie failure?
When a wall tie rusts and expands, the brickwork moves and the mortar no longer adheres to the brick. This results in the wall becoming unstable.
The image shows an old style wall tie that has been badly corroded. This happens when rainwater seeps through gaps in the pointing.
What are the consequences of wall tie failure?
Corroded wall ties can devastate a property. In the most severe cases – as with this terraced house in Fenton, Stoke-on-Trent – part of the house is having to be rebuilt.
As John alludes to in the video, cracks in brickwork can sometimes be repaired using brick stitching. However, in this case, the wall was in such a poor state that it had to instead be rebuilt.
Key moments from the video
0:44 – John shows us the rear wall of the property, which has been partly removed because of the consequences of wall tie failure.
3:13 – When pointing perishes on the outer wall, rainwater seeps into the wall. Wall ties get wet, begin to rust and start to expand.
3:38 – The pointing on this particular property had perished to the point that it was possible to see daylight through the brickwork.
3:56 – Helifix brick stitching can be used for repairing structural failure in brickwork. But this wall was too badly damaged for this method.
4:28 – Modern wall ties (brick ties) are made from stainless steel and, therefore, far less susceptible to rust.
5:51 – The rear wall of the property is so badly damaged due to the corroded wall ties that the brickwork has started to bow under pressure.
“I was in the process of purchasing an investment property. There were several structural issues with the property including wall tie failure. I required an experienced person to advise on the best solution to move forward. John was able to advise not only from a structural/building point of view but also from an investment perspective.”
Moghees Mir – Property Investor
“I was in the process of purchasing an investment property. There were several structural issues with the property including wall tie failure. I required an experienced person to advise on the best solution to move forward. John was able to advise not only from a structural/building point of view but also from an investment perspective.”
Moghees Mir – Property Investor
How to spot wall tie failure
In the first video in this mini series, John explains how you can spot a wall where the brick ties have failed.
Look out for horizontal cracks or gaps in the mortar.
In the image below, John is outside the affected property and its neighbour. See how the rows of bricks appear to not be in line with each other.
This is a telltale sign of wall tie failure.
How to fix wall tie failure
A Structural Engineer will be able to determine which method is needed to properly repair a wall with failed wall ties.
Sometimes, remedial works – such as brick stitching – are possible. In more serious cases, the wall may have to be rebuilt.
