Cavity Wall Insulation Problems
Common issues with Cavity Wall Insulation
Cavity wall insulation has long been considered a practical solution for improving energy efficiency and reducing heat loss in buildings. However, over time, it has become evident that old, defective, or poorly installed cavity wall insulation can lead to a range of problems.
Various insulating materials have been used over the last 9 decades to fill cavity walls, including Injected Urea Formaldehyde Foam, Polystyrene Beading and Blown Mineral Wool. Each of these materials can cause issues related to age, degradation, and poor installation that will need remedying:
Dampness and Moisture Accumulation
One of the primary concerns with faulty cavity wall insulation is the potential for dampness and moisture accumulation. If insulation materials become wet due to external factors such as leaks or condensation, they lose their insulating properties and damp can penetrate to internal walls and create an environment conducive for mould to grow. This can lead to unpleasant odours, respiratory health issues, and damage to the property's structure.
Insufficient Insulation Performance
Old, degraded, or poorly installed cavity wall insulation may not provide the desired level of thermal efficiency. Gaps, voids, or incorrect installation techniques can result in thermal bridging, where heat easily escapes through uninsulated areas. As a result, the property may experience increased heat loss, energy inefficiency, and higher heating bills. The most common causes of reduced insulation performance are:
Material Degradation and Settling: Over time, certain insulation materials used in cavity walls may degrade or settle, compromising their effectiveness. For instance, if the insulation is made from mineral wool, it can sag or settle, leaving gaps that allow heat to escape. Similarly, foam-based insulations can shrink or deteriorate, leading to decreased performance and the need for remedial action.
Voids and Bridging Caused by Poor Installation: Improper cavity wall insulation installation techniques, such as inadequate filling or bridging, can create voids within the cavity wall insulation. These voids allow air movement and diminish the insulation's efficiency. Additionally, insulation materials can bridge across the cavity, rendering parts of the wall uninsulated and susceptible to heat loss.
Nesting Insects and Vermin Infestation
In some cases, defective cavity wall insulation can attract nesting insects and provide a cosy environment for vermin infestations. Gaps or open cavities within the insulation can become nesting sites for pests such as wasps, bees, rodents, or birds. Apart from causing structural damage, these infestations can create nuisance, health hazards, and the need for costly pest control measures.
