Property Surveying Blog
Whilst carrying out day-to-day inspections we come across a number of interesting things that people not involved in the building trade may be unaware of.
A common site to our surveyors is wall tie bars or lateral restraint bars.
What are they?
Not to be confused with wall ties used to connect the two leaves of a cavity wall together, structural wall tie bars, are used to fix together two opposite external walls in a house that have begun to bow or lean away from each other.
This is achieved by inserting a long metal bar or bars from one side of the house to the other, through the floor joists to connect both walls back together.
This transfers some of the load on the wall to the floor joists to stabilize the wall movement.
By fixing a number of these bars throughout the length of the wall, the installed ties reduce the chance of any future to the wall.
Why would walls begin to move in the first place?
As with many structural problems in property, older properties or houses tend to reveal a larger amount of defects mainly because they weren’t constructed to the improved standards that properties are today.
The main culprit for bowed walls are that when originally constructed, the walls were poorly fixed to either the roof or the floors within the building. This means that there was no lateral support to the walls, leading them to pull away from one and other.
The walls therefore cannot support as much weight as well constructed properties; so when homeowners embark on a loft conversion, or renew their old slate roof with new heavier concrete tiles, the walls buckle and bow under the newly added weight!
The buckling and bulging of the wall will most likely happen slowly over time as the weight redistributes itself within the property and will likely go unnoticed in the hustle and bustle of everyday life.
Can you recognise a house with these installed?
A house that has had wall tie bars installed will usually have a decorative wall washer or anchor plates made from cast iron and are therefore easy to recognise.
These anchor plates come in a number of different shapes, from highly decorative ‘S’ and ‘X’ shapes, to traditional shapes such as circles and squares as they are often made into decorative feature on the property.
Do they actually fix the problem?
Generally speaking, tie rods or wall tie bars will not stop the movement. However, they can stop the symptoms of the problem and importantly stabilise the movement in a temporary fashion.
As with any property defect it is always best to get to the root of the issue.
This issue could be down to the wrong type of tiles on a roof of a period property, adding too much load to a solid brick wall with a shallow foundation, or the need to correctly tie the walls into the roof and floor structure.
Once the issue has been identified correctly, it can then be fixed effectively and will reduce the risk of any further movement, however, your new decorative anchor plate will still look good on the side of your property many years later.