Easy to install insulation and prevents heat from escaping through the roof.
Fills the gaps between wall cavities to help to help keep your home warmer
Insulation in your converted roof space creates a blanket effect to trap heat within the home
Can be installed in properties that have a suspended floor or a cavity underneath
Provides an option for properties that do not have any wall cavities by adding insulation to internal walls
A useful option for solid walled properties unable to benefit from cavity wall insulation
To explore this type of insulation, we first need to understand what a cavity wall is.
Some walls are solid walls, with no interior cavity. Solid walls need to be insulated by adding a layer of insulation either to the inside or the outside of the walls. A cavity wall, on the other hand, comprises two walls with a gap in between. The outer wall tends to be made out of brick, with the inner wall usually being made of brick or concrete.
If you’re unsure which type of walls your home has and if it is suitable for cavity wall insulation, there are a few easy ways to check.
If your home has cavity walls, the bricks usually have an even pattern with all the bricks laid lengthways. The bricks on solid walls tend to have an alternating pattern, with some bricks laid across the wall allowing you to see the smaller ends from the outside.
You can also tell by measuring the width of a wall. If a brick wall is more than 26cm thick, it likely has a cavity.
Cavity walls perform an important function. They were originally introduced to allow air streams to blow into the hollow space between inner and outer walls and create a drying action. The cavity also allowed for the home’s masonry to drain any moisture into a safe place, so it’s great for keeping homes safe from damp.
To install wall cavity insulation, you’ll need to hire a professional to insert a heat-retaining material into the gap between the two layers of the wall. This prevents most of the heat in your home from being able to escape.
According to the Energy Saving Trust, about a third of the heat lost in an uninsulated home escapes through the walls, which underpins the importance of making sure this space in your home is adequately insulated. Most houses built from the 1990s onwards have some sort of wall insulation, possibly cavity batts which can fail over time, but homes built prior to this might not have any at all.
In some instances there may be problems with cavity wall insulation that has previously been installed incorrectly. Insufficient insulation, or uneven cavity wall insulation, can cause cold bridging or weak spots in the insulation continuity and lead to issues such as mould. Retrofit cavity wall insulation could also have been done badly previously leading to a host of cavity wall insulation problems that need remedying.
Naturally, in a solid wall, there is no cavity to insulate. Instead, you’ll have to opt for either internal or external wall insulation, which is added to either the inside wall or the outside of your home.
Solid wall insulation is a good option for people with older properties, but there is the risk of some complications with moisture and condensation, so be sure to find a reliable installer and discuss the process with them before going ahead.
External insulation is much less invasive and doesn’t take up space in your home in the way internal insulation does, but the benefits come with a hefty price tag. If you’re on a strict budget to insulate a solid wall, internal insulation provides a cheaper alternative.
Naturally, cavity wall insulation costs will vary depending on different factors. Insulating a large detached house will cost more than insulating a flat, and you may pay a different price depending on where you live in the country.
Prices for installation in the North will tend to be cheaper than the prices in the South East, for example.
There are two parts to the cost of cavity wall insulation – labour and materials. The price for the materials is what you pay for the type of insulation being used, while the labour is what you pay to have a professional come and install it.
Because of the specialist equipment and techniques needed to install cavity wall insulation, it’s not something you should take on as part of a DIY project, so labour costs are unfortunately unavoidable.
Make sure you’re getting bang for your buck by working with trusted professionals with a record of success. Some insulation materials, such as cavity foam insulation, are also more expensive than others, so the price will differ depending on the type of insulation you choose.
In general, you can expect to pay approximately £200 per cavity wall. Imagine you own a mid-terraced home, for example. You’ll only need to insulate the external walls (not the ones that connect to another home), so that would cost you around £400.
You can expect to pay more for a detached property, but bungalows are the cheapest type of detached property because the walls are shorter.
Cavity wall insulation is much cheaper than solid wall insulation, which tends to cost thousands of pounds.
DIY insulation is certainly possible, especially with blanket insulation. If you meet the following criteria, DIY insulation will be a possibility:
On the other hand, if any of the following criteria apply to you, it’s time to call in the pros:
Whatever the condition of your loft, don’t undertake an insulation installation job lightly. DIY projects of this kind can quickly get messy, and if you fail to install insulation properly, you could be left with insulation that doesn’t work effectively, or, worse, actually causes damp problems.
To start with, it’s worth checking whether your cavity walls are already insulated, which is a high possibility if your home was built in the last 20 years. If your cavity walls are already insulated but you still want to improve your home’s energy performance, consider other types of insulation.
If you’re not sure either way, ask a professional installer to perform a borescope inspection to explore your wall or check with your local authority.
Cavity wall insulation isn’t suitable for every type of property. Check whether your home meets the below criteria before having cavity wall insulation installed.
You should then ask your installer of choice to carry out a survey to assess whether your property is suitable. If you live in a flat, you’ll need permission from the people in the surrounding flats before you go ahead with installation.
Despite the cost-effectiveness of cavity wall insulation, its price point makes it inaccessible to millions of people around the country. The good news is, there are many grants available to those who need them, to make their homes more efficient and help reduce the costs of their energy bills.
You may be eligible to have cavity wall insulation installed for free if you receive one of the following benefits.
If installed properly, cavity wall insulation should last in many instances for as long as you are living in the property itself – this could be many decades. The improved thermal insulation brings energy bill savings that add up over time.
This means that if you spend a few hundred getting a cavity barrier installed, you’ll make your money back multiple times over in savings by the time you come to move out of your home. In fact, most homeowners are expected to get payback on the cost of installing cavity wall insulation within 2-3 years.
Switchable partners with hundreds of fully approved insulation installers throughout the UK. We only work with the best in your area.
Naturally, it can be overwhelming to look for the right cavity wall insulation installer, but there are some easy steps you can take to find the right one.
If you’re not sure whether your walls have wall cavities or are solid walls, or indeed if you already have cavity wall insulation, you can always ask a professional installer to check. It is usually possible to find out just by viewing the outside walls or looking for signs of drill holes or small homes made by a previous wall cavity installation. A professional installer will also be able to advise on the best form of cavity wall insulation for your home.
Whichever type of insulation you opt for, you’re sure to reap rewards with a much more energy efficient home. In most cases, you can expect your insulation cost to be covered in just a few years through reduced heat loss and energy bill savings.
There’s nothing worse than shivering in your home during the colder months, especially if you’re worried about energy consumption and heating costs and therefore reluctant to put the heating on.
One of the biggest advantages of cavity wall insulation is that it helps to keep your house warmer throughout the seasons, meaning you don’t have to overly rely on other methods such as radiators, electric heaters, and heated blankets.
Cavity wall insulation can save hundreds on your annual heating bill, which is especially helpful when the cost of living is high. Cavity wall insulation can knock around £200-400 of your energy bills per year (depending on the type of property you live in), meaning your investment could in some instance pay for itself in around 8 years.
Every homeowner wants one thing from their home purchases – a return on investment. That’s exactly what cavity wall insulation provides.
Having cavity wall insulation installed inevitably involves a cost (the amount varies depending on the material used) but this form of insulation will tend to pay for itself multiple times over within its lifespan.
Cavity wall insulation costs are higher than some other insulation alternatives such as mineral wool insulation, but it is a highly effective insulating material. Over the decades you can improve your home’s energy efficiency to save thousands.
Not to mention that cavity wall insulation can actually increase the value of your home. Potential buyers are always looking for ways to reduce their costs, and offering a home in which insulation has already been installed is a great way to differentiate your property from others on the market.
Most of our homes are heated by burning fossil fuels, which isn’t great for the environment. If running a home that’s easy on the planet as well as your wallet is a priority, look no further than cavity wall insulation.
Having insulation reduces your dependence on using central heating to warm up your home, which in turn reduces the amount of fossil fuels you burn. If everybody in the country opted to insulate their cavity walls, our national carbon footprint would decrease significantly.
Many homeowners are put off insulating unfilled cavity walls because they fear it would be an overly disruptive process. This couldn’t be further from the truth. Installing cavity wall insulation is usually quick and straightforward when installed correctly by a professional.
With no complications, you can expect your insulation to be installed within a day – it usually takes no more than a couple of hours. Since the work is done by accessing through the outer walls, you’ll face very little disruption.
If the installation requires cavity wall insulation removal because the existing insulation has failed then this can make the installation task a little longer as the old material needs to be broken up by compressed air and then gathered up by an industrial vacuum.
Cavities were not originally introduced as a place to store insulation. As insulation has become more popular over the years, however, the size of the cavities has increased to allow for the installation of effective cavity wall insulation.
Keep in mind that if you own an older home, the cavity may not be wide enough to fit the amount of insulation needed without causing issues. For this reason, it’s worth consulting with an expert to check that this type of insulation is suitable for your property.
Retrofitting older properties with insulation is naturally more challenging than building a new property with the insulation installed at the time, so don’t undertake this project without being sure it’s suitable.
Cavity walls aren’t there by accident; they perform a crucial role in your home’s structure, which is to keep out rain driven in by the wind. There is a small risk that if you install insulation poorly, moisture can bridge the cavity and enter your home, although this is unlikely.
Another small issue is the possibility of the wall ties (the metal rods that hold each side of the wall together) rusting when cavity wall insulation is injected. The best way to fight the possibility of damp and cavity wall insulation moisture in the home is to ensure there’s adequate ventilation elsewhere.
To avoid damp cavity wall insulation, make sure it’s installed properly by professional installers. If you notice there’s no increase in temperature and mould and condensation are showing up in your home, this indicates that the insulation was likely installed poorly. In this case, it’s best to get a professional to take a look at how to resolve the situation.
