Understanding Cavity Walls in Homes

Posted on 15th May 2024 at 12:00

Here at the National Waterproofing Group, as well as specialising in waterproofing and gas membrane installation, some of our members also provide wall stabilisation.

Cavity walls are a common feature in many residential buildings, designed to improve insulation and protect against moisture. This blog explores what cavity walls are, their purpose, the reasons they sometimes fail, and how professional contractors can provide essential wall stabilisation services.

What are cavity walls and what do they do?

Insulation

One of the primary purposes of cavity walls is to improve thermal insulation. The cavity acts as a barrier that reduces the transfer of heat between the interior and exterior of the home, helping to keep the house warmer in winter and cooler in summer. This can lead to significant energy savings and increased comfort for occupants.

Moisture protection

Cavity walls are also effective at preventing moisture from penetrating the interior of the home. The outer leaf is designed to absorb and shed rainwater, while the cavity provides a break that prevents moisture from reaching the inner leaf. This design helps protect the interior walls from dampness and related issues like mould and mildew.

Structural stability

In addition to insulation and moisture protection, cavity walls contribute to the overall structural stability of a building. The two leaves of masonry, often tied together with metal ties, provide a strong and durable construction.

Why do cavity walls sometimes fail?

Despite their advantages, cavity walls can sometimes experience failures due to various reasons:

Poor construction

One common cause of cavity wall failure is poor construction. If the cavity is not properly maintained or if the wall ties are incorrectly installed, the structural integrity of the wall can be compromised. Over time, this can lead to issues such as cracks and bulging walls.

Wall tie corrosion

Wall ties, which hold the two leaves of the cavity wall together, can corrode over time, especially if they are made from materials prone to rust. When wall ties fail, the two leaves of the wall can start to move independently, leading to structural instability and visible defects.

Moisture ingress

While cavity walls are designed to protect against moisture, they can still suffer from moisture ingress if the outer leaf becomes damaged or if the cavity is bridged by debris or insulation material. This can lead to dampness, mould growth, and deterioration of the wall materials.

How a professional contractor can help: Wall stabilisation services

Wall tie replacement

One of the primary services offered by contractors is wall tie replacement. Professionals can assess the condition of existing wall ties and replace any that are corroded or damaged with new, corrosion-resistant ties. This process restores the structural integrity of the cavity wall, ensuring that both leaves are securely bonded together.

Crack repairs and reinforcement

Contractors can also repair cracks and reinforce weakened areas of the wall. By addressing these issues promptly, further damage can be prevented and the structural stability of the wall can be restored.

Cavity clearance and insulation

In cases where the cavity has become bridged or filled with debris, professional contractors can clear the cavity and ensure it remains free of obstructions. Additionally, they can assess and upgrade the insulation within the cavity to improve thermal performance whilst ensuring it does not compromise moisture protection.

Comprehensive assessment and maintenance

Professional contractors provide thorough assessments of the entire wall system to identify any potential issues that may not be immediately visible. Regular maintenance and monitoring services can help to detect and address problems early, preventing costly and extensive repairs down the line.

Ask us about wall stabilisation

If you require wall stabilisation, please fill in our contact form to book a callback from a National Waterproofing Group member in your local area.