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Cavity Wall Insulation – Good or Bad?

Cavity Wall Insulation good or bad

Cavity Wall Insulation Good or Bad?

This article will go through the age old question cavity wall insulation good or bad - let's get right into it..

Years after cavity wall insulation first became one of the preferred insulation methods of choice, people have started to question the impact that it has on their homes.

Most brick homes built since 1970 in the UK, and certainly many built between 1930 and 1970, have cavity walls. Most of these homes have a cavity of about 2 inches, which is considered the ideal specifications for cavity wall insulation.

In terms of materials, there are three main products to choose from: blown mineral wool fibre, polystyrene beads and urea formaldehyde foam.

Mineral wool fibre is the most common, however, over time, individual fibres come apart, leading to sagging, lagging and air leaks.

 
Cavity Wall Insulation

The Concept

The idea of cavity walls was to create an air break between the two parts of the wall, to prevent damp forming along the interior of the wall of the home.

When the weather is wet the damp will run down the exterior part of the wall and then dry out, preventing damp from getting into the interior of the home.

The cavity has not always been successful in keeping damp out and the cold air within the cavity has made keeping homes warm more difficult.

So, in general, is cavity wall insulation good or bad? The government believes it’s beneficial; in fact, together with energy companies, they now sponsor the installation of cavity wall insulation.

Mineral wool fibre has proven to be less waterproof than previously thought, and is believed to degrade under damp conditions.

Furthermore, after the insulation procedure has taken place, it can easily sag and settle, causing empty gaps to form, with thermal efficiency greatly reduced.

 
Cavity Wall Insulation

What Are The Options?

Polystyrene balls, while far more waterproof than mineral wool fibre, are not environmentally friendly, and can also settle, causing those infamous cold spots that form when the insulation has a gap in the wall.

While overall these methods are considered successful, the implementation of foam as an insulation agent started to die out, because of the belief that it degrades quickly, in comparison to the other two aforementioned materials.

However, such myths have been thankfully dispelled; exterior wall insulation performs for the life of the building, making it the most cost-effective choice long-term.

It has now been established that cavity wall insulation, by creating a bridge between the two walls, facilitates the ingress of damp into the property, where the insulation material has lost its damp proofing properties, or wasn’t particularly damp proof in the first place.

When it comes to cavity wall insulation, good or bad points generally come down to the type of insulation that is used.

More recently, changes in the approach to cavity walls have started to surface, and both newer materials, and newer methods, are being used to approach the problem.

Modern Solutions: Why They Matter

The use of more effective spray foam insulation has become more widespread; this foam when applied naturally expands to ensure that there are no cold spots or gaps left in the wall.

There is also a method used to seal the brickwork from the exterior.

Bricks and natural stone are porous building materials, and allow cold and damp to cross over into the interior of a house.

However, with the application of Home Logic External Wall Insulation, homes remain warm in Winter and cool in Summer and thus far more conducive to comfort. Result!