External wall insulation is a great option when it comes to improving the insulation of a building. It is an efficient way to reduce heat loss and improve thermal performance through the 'tea cosy' effect (also known as the envelope), and can dramatically improve a property's energy efficiency.
Perfect for most buildings built before 1930, which had mostly solid walls instead of cavity walls, external wall insulation offers an insulation system for those who simply cannot have cavity wall insulation.
But how does it work? How do teams like MisterRender install it? Here's what you need to know.
When you first contact MisterRender about external wall insulation, or even before then, if you've done enough research, you will need to check a handful of things.
The first thing you need to be sure of is whether your home is suitable for external wall insulation. This means checking for solid walls. The best way to check for this is by looking at the brick wall. If you have lots of square brick ends in your brick pattern, then it is likely that you have solid walls and can have external insulation installed.
Once you know that, you should check whether or not you can have external wall insulation boards installed without planning permission. In most cases, planning permission isn't needed for external wall insulation but it is always worth checking. If you live in a listed building, or you live near an area of conservation or of outstanding national beauty, then you might have to have planning permission in place. If you are hoping to completely change your property's appearance with external wall insulation, you may also need to check in with your local authority before you get started.
Discover: Does External Wall Insulation Require Planning Permission
As well as the legal and logistical preparation for external wall insulation, you may also want to check and prepare your external walls. To do so, you should:
You can't install external wall insulation on walls with any structural issues, so take a good look at your solid walls and see whether you can spot any cracks or crumbling sections.
External wall insulation needs to happen on clean walls, so it wouldn't be amiss for you to give your solid walls a good clean with soapy water before external wall insulation installation.
Moisture is a huge issue in walls. It can cause structural concerns if left unchecked, and beneath render it can cause blow-outs and cracks that lead to the render being destroyed. Before you start to install external wall insulation or have anyone come to do so, be sure to check your walls for any signs of moisture.
If you've got anything hanging on your walls, or anything in pots by the walls, these should be removed. The professionals need uninterrupted access in order to get your external wall insulation properly installed.
A render test is the first step. It will tell the professionals whether the existing wall cladding is strong enough to support the insulation boards and new render. If the render is strong enough, then we can go ahead and smooth it out. Then the insulation boards can be applied directly on top.
Failing that, though, the existing render must be completely removed before the installation process can begin. Otherwise, the insulation material and new render will not last.
Once the render has been tested and dealt with accordingly, the pipework needs to be removed from the building. This also involves the installation of temporary downpipes to prevent water from running down the wall, as well as the extension of waste and soil pipes.
This step in the process is designed to ensure that you can still use your home to the fullest extent while we work to install external wall insulation.
If needed, the MisterRender team will then fit a protective layer over any windows and doors to prevent them from being damaged while we are installing external wall insulation.
External wall insulation doesn't usually go right down to the ground. So the first step in applying the external wall insulation system to the wall is deciding where it begins. We will then install an aluminium start track. This helps us to know where to go from and helps us throughout the process.
The application of the insulation boards themselves can then begin! A layer of adhesive goes on each board and they are stuck to the wall in a slightly staggered pattern. If need be, we will cut and trim insulation boards to fit around windows and doors.
As soon as the insulation boards are stuck down, we use a rasp to file off the edges where needed. This helps to make sure that the surface is completely flat.
The boards are not held up solely with adhesive. We also attach around ten fixings per square metre to secure the boards to the wall. This helps to make sure that the insulation boards don't come loose in bad weather.
For extra security, we then add corner beads and stop beads. These are really useful in that they help keep the insulation boards secure and tight around windows, doors, and obstructions. Beading allows us to form tight edges that are essential for optimal performance.
We then apply two layers of a special render to the surface. This render has strengthening properties that lend themselves to further securing the insulation boards. In between the two layers, we place fibreglass mesh.
Once the render has dried completely, a coat of primer is painted over it. The primer has particles that help the final render coat to stick. It will be the same colour as your final product to ensure there is no colour shining through the cladding at the end.
The final and visible coat of render is then plastered onto the wall. It will be whatever colour and texture you have discussed with the MisterRender team leading up to the external wall insulation installation.
Any pipework and pictures that were originally removed from the property can be reinstalled. If there were any openings in the render for pipework, they would be sealed completely.
The window sills, at this stage, may need replacing or extending. Likewise, verge trims may need to be adjusted or replaced to make up for the newly extended wall.
Now that the external wall insulation is done, and your solid walls are properly insulated - what comes next? Well, there is a matter of cleaning up the workspace.
Usually, cleaning up after external insulation has been installed involves removing any excess adhesive, sweeping, washing and vacuuming the work area. The team will need to dispose of any waste materials as per any local regulations.
Explore: How Much Does External Wall Insulation Cost
Now that the external wall insulation part is done, it is important to know how to look after your solid wall insulation. This will make sure that the solid wall insulation will last longer, providing you with energy efficiency and lower energy bills for as long as possible!
The best ways to maintain solid wall insulation on external walls are:
Check out: How Long Does External Wall Insulation Last
There are a number of things that can go wrong if you don't know what you're doing. That's why we recommend always hiring a team of professionals like MisterRender. That way you can avoid the incorrect installation of the insulation boards, usually caused by insufficient adhesive.
Another common mistake when EWI systems are installed by DIYers is failing to allow for proper ventilation. This leads to mould growth and moisture build-up within the system. Likewise, failing to seal gaps and openings can allow moist air in and out, not only causing build-up but decreasing the effectiveness of the solid wall insulation!
Fortunately, the whole team at MisterRender is experts in their field, so you can trust that when your solid wall insulation is in our hands, it won't go wrong.
