When it comes to improving your home's energy efficiency, cavity wall insulation is one of the most effective upgrades. However, not all insulation materials are created equal; there are a variety options, each with unique characteristics – but some come with drawbacks, especially over time.
So, if you’ve ever wondered what’s going on inside your walls, and what the best solution is to keep your home warm and cosy – read on!
Types of Cavity Wall Insulation
Urea Formaldehyde Foam (UF Foam): The most common and popular form of cavity wall insulation back in the 70s and 80s in particular, this foam insulation is sprayed into the cavity, expanding to fill the gap. However, over time this material will degrade and lose insulating properties. It’s also known to absorb moisture, leading to damp and even mould.
Unfortunately, once degraded it will need to be removed before new insulation can be installed – and extraction is time consuming and expensive – requiring two day’s work with an industrial hoover, adding £3000+ to the bill for an average four bed detached home.
Mineral Wool (White or Yellow Blown Fibre): This a popular method of insulation has been used for decades and is still being deployed now, with developers often favouring this option for its low cost and decent thermal performance – at least initially!
However, blown fibre is prone to settling over time, leaving gaps in the insulation. This not only reduces efficiency but leads to cold spots, and that thermal difference can result in condensation and damp. It is also known to retain moisture; when it’s wet, it will potentiallybridge the cavity, again creating issues with damp on internal walls.
EPS Bead Insulation: Foam beads are lightweight, water-resistant, and thermally efficient. They don’t settle over time, ensuring consistent performance. The beads resist moisture absorption, reducing the risk of damp and mould issues.
While foam bead insulation may initially cost more, the cost differential isn’t huge – and its longevity and performance make it a worthwhile investment.
Common Issues with Cavity Wall Insulation
Proper installation and material choice are critical to avoiding issues. Poorly chosen, poorly installed or old and degraded cavity wall insulation can actually cause more problems than it solves.
For example, insulation materials that absorb or wick moisture can create a thermal bridge between the outer and inner walls, leading to damp patches, mould growth, and damage to interior finishes. While insufficient or uneven insulation creates thermal differences across the wall. These differences can cause condensation, which may lead to dampness, mould, and even structural issues.
Some materials, such as mineral wool, which settle over time, are especially prone to leaving gaps in the insulation, reducing thermal performance and leading to cold spots. Andremoving poorly performing or degraded insulation, such as UF foam or mineral wool, is often complex and costly. Improper extraction can even damage the wall structure.
Advantages of EPS Bead
EPS bead insulation addresses many of the issues associated with other materials. Chief among its advantages is its durability; unlike blown fibres or UF foam, foam beads don’t settle or degrade over time. Our product, a modern EPS Bonded Bead, is guaranteed for 25 years but will last far beyond this – if undisturbed, it should last for the life of the property.
Our bead insulation, which is also a recycled product, provides an extremely high level of thermal wall efficiency – improving the U-value (a measure of how effective a material is at preventing heat transfer) by 70% compared with a standard uninsulated cavity wall.
The beads are small and lightweight allowing them to flow into every crevice, eliminating the issue of gaps and voids. They don’t absorb moisture, avoiding damp problems or thermal bridging. And should you ever need to, they are also easier to remove compared to other insulation materials.
Cavity wall insulation is certainly the right step to take if you want to make sure your home is warm, dry, and energy-efficient home – but make sure you choose wisely.
If you’re considering cavity wall insulation or looking to upgrade an existing system, get in touch with us today. Our team of experts are ready to assess your property and offer a solution that’s right for you.
