Cavity wall insulation is hailed as an effective way to improve heat retention for existing buildings. However, it’s not without its problems. It’s important to be aware of these potential issues before deep diving into a full-scale retrofit.
In this post, we’ll discuss five cavity wall insulation problems and how to avoid them.
1. Not suitable for solid walls
One of the most fundamental cavity wall insulation problems is that’s it not suitable for all homes. As the name suggests, cavity wall insulation requires a wall cavity where insulation can be added. Some homes built in the early 20th century or earlier will have solid walls rather than cavity walls.
If you’re unsure of your wall type, measuring can usually give you a good idea. Walls that are over 260mm thick will usually have a cavity, while narrower walls are most likely solid.
2. Or areas with wind-driven rain
Other buildings that are unsuitable for cavity wall insulation are those in areas with wind-driven rain. A map from the NHBC shows that the main areas of exposure are along the west coasts of Scotland, England and Wales.
Wind-driven rain soaks external brickwork, which can lead to water ingress and cavity wall insulation becoming damp. Once damp, it loses its insulating properties, rendering it ineffective for heat retention.
3. Penetrating moisture
If water does get through your external brickwork, it might not be a problem when there’s a cavity in your wall. However, by filling that void, cavity wall insulation essentially acts as a moisture bridge. It allows moisture to pass through the entire wall and into your building. That can lead to damp and mould inside your home, plus the eyesores and health risks that come with it.
Another problem comes with breathability. Above all else, cavity wall insulation aims to stop heat getting through your external walls. In doing so, however, it can also prevent moisture from escaping. Without alternative ventilation, that moisture becomes trapped in your home, causing humidity levels to rise and – as above – issues with damp and mould to develop.
5. Cold bridges
If cavity wall insulation isn’t installed correctly, there’s also the problem of inefficiency. Any underfilling, slumps or gaps can lead to cold bridges in your walls. These areas allow the cold through, creating concentrated cold areas within your home. They are basically a magnet for moisture and damp, not to mention making the insulation itself much less effective.
An alternative to cavity wall insulation
From unsuitability to cold and moisture bridges, there are a range of cavity wall insulation problems that make it ineffective, and even damaging, to your home. Corksol provides an alternative, with internal and exterior wall coatings that add insulation without these issues.
Our natural SprayCork solution is highly insulative, breathable and completely moisture-resistant, so you can keep your home well insulated while also avoiding issues with damp and mould. Get in touch today to arrange a quote.