As we move into the warmer months, many homeowners turn their attention to external property maintenance. While visible elements like roofs and render often take centre stage, there’s a critical component hidden within your walls that deserves attention: cavity wall ties. These small but mighty elements play a vital role in your home’s structural stability, and their deterioration can lead to significant problems if left unaddressed.
What Exactly Are Cavity Wall Ties?
Most modern properties in the UK are built with cavity walls, consisting of two separate masonry walls (an inner and an outer leaf) with a gap or cavity between them. Cavity wall ties are small metal strips or rods embedded in the mortar of both walls, connecting them across the cavity. Their primary purpose is to tie the two leaves together, preventing them from bowing or collapsing, especially in strong winds or due to general structural movement.
Over time, particularly in older properties, these metal ties can be susceptible to corrosion. This is often due to moisture ingress within the cavity, or simply the age and material of the original ties. As they corrode, they can expand, losing their strength and potentially cracking the surrounding mortar and brickwork. Improper installation during construction can also lead to issues.
Recognising the Subtle Signs of Failure
Since cavity wall ties are hidden from view, identifying their failure requires keen observation of external signs. Here are the key indicators that your wall ties might be compromised:
- Horizontal Cracking in External Walls: Look for cracking along the mortar joints, particularly at regular intervals, often corresponding to the lines of the wall ties. These cracks can appear above windows, below rooflines, or elsewhere across the facade.
- Bulging or Rippling of Brickwork: As corroding ties expand, they can exert pressure on the outer wall, causing it to bulge outwards or appear rippled. This is a more advanced sign and indicates significant movement.
- Cracks Around Openings: Cracks radiating from the corners of windows and doors can also be an indication of structural stress caused by failing wall ties.
- Rising of the Outer Wall: In severe cases, the outer leaf of the wall may appear to rise slightly, resulting in uneven courses of brickwork or lifting of the roof particularly on gable end elevations.
It is also important to note that whilst the above is true, depending on the type of existing wall ties present, corrosion can occur without causing visual defects.
The Impact on Your Property’s Value and Future
Failing cavity wall ties are more than just a cosmetic issue; they represent a significant structural concern. If left untreated, the deterioration can compromise the entire stability of the outer wall, potentially leading to costly and extensive repairs.
For homeowners looking to sell, evidence of corroding wall ties will almost certainly be highlighted in a buyer’s survey. This can deter potential purchasers, lead to significant price reductions, or even affect mortgage applications, as lenders may be unwilling to provide financing on a structurally compromised property. Proactive maintenance ensures your home retains its full market value and appeal.
The Importance of Professional Assessment
A specialist assessment will accurately determine:
Given the critical nature and hidden location of cavity wall ties, a professional assessment is absolutely crucial if you suspect an issue. A qualified surveyor or property care specialist can use non-invasive techniques, such as boroscopes, to inspect the ties within the cavity without causing significant disruption.
- The extent of corrosion or failure.
- The type and number of wall ties present.
- The appropriate course of action, which typically involves installing new, non-corrosive wall ties and, in some cases, isolating or removing the old ones.
Proactive maintenance of your home’s unseen foundations is key to its long-term health and value.
If you’ve noticed any of the signs mentioned above or simply want peace of mind regarding your property’s structural soundness, a professional survey from experienced property care specialists is the recommended first step. Ensuring the integrity of your cavity wall ties is an investment in your home’s future.