External wall insulation in Knebworth

Before the commencement of any project, it’s always best to get an estimation of the cost. However, determining the cost of an external solid wall insulation is not the easiest of tasks as it relies on varying components such as the insulation materials to be used, labour cost and installation as well as the type of decorative finish to be incorporated. And depending on your choice of insulation material, some may need some adhesives while others may require some fixings which also contributes to the differences in price. As a result, the determination of the material cost alone can be tricky and even more so when various materials cover varying areas.

With that in mind, the cost of external solid wall insulation generally ranges between £80 to £100 per square metre2. As a result, a small flat can cost from £6000 to £9000 whereas a large detached house can have a price ranging between £21000 to £23000. To earn back your investment in terms of energy bill savings can take a couple of years, but it’s surely worth the try as there are several other benefits associated with installing an external solid wall insulation system. What’s more? Another huge factor that can influence the cost of your system is also the amount of work that’s required, how easy it is to be accessed by the installers and lots more

If you’re looking to cut down on the cost of your external solid wall insulation, then the best time for an installation might just be when you’re having another decorating or building project done such as fitting a new roof, window painting, installation of solar PV panels and more. This way, you’ll be able to spread the cost and have a greater value for each penny expended.

With the title of this blog, do not be deceived into thinking the purpose is to encourage you to install an external insulation by yourself. Even as a competent DIYer, it’s not advisable to buy a couple of materials and start slapping it into the wall hoping for the best outcome. External insulation is by no means a DIY job and without the proper training and experience, it can easily turn out disastrous resulting in loss of time, effort and money in such a valuable project. This blog, however, will give you a great insight on how the installation process works and help maximize knowledge ensuring you do not spend more than necessary.

External Insulation Installation

lRender Test

• This is done to ensure the existing render is good enough for insulation support.

• If positive, the insulation can be applied directly onto it.

• If negative, ensure removal of the old render before fitting the insulation.

lPipework Adjustment & Removal

• Remove all pipework prior to insulation fitting

• Install temporary downpipes to ensure water is not wasted and everything continue to function normally during the insulation fitting process.

lWindow Protection

• Protect the window with a protective layer or film.

lStarter Track Fitting

• Determine level you want the insulation to start (height).

• Fit the aluminium start track or carrier tray at the identified level.

lInsulation Boards Fitting

• Apply a layer of adhesive to the board and glue them to the wall in a staggered pattern.

• Cut to fit round all obstructions and windows.

• File off the edge of the board where necessary using a rasp upon successful fitting of the boards

lMechanical Fixing Inclusion

• Hammer around 10 fixings per square metre into the board.

• This is to secure the insulation boards.

lBeading Fitting

• Add corner beads and stop beads to ensure the insulation is secure and to prevent it from making contact with other materials.

lReinforcing Mesh & Render Addition

• Apply two layers of strengthening properties and between the two layers of render, include a fibre glass mesh.

lPrimer Application

• Paint on the primer

lFinal Render Application

• Choose your most preferred texture and colour as this will be the last coating of the installation process.

lPipework Re-installation

• Re-install all detached pipework at the start of the installation process.

With the numerous benefits that comes with the installation of an external wall insulation in a building, it’s also important to find out whether it’s also safe before proceeding to fit one in your home. Firstly, to ensure that external wall insulation systems are safe, they must be BBA approved, which means they’ve been subjected to a thorough testing by the British Board of Agrement and therefore, suitable for use in UK homes.

Given the fact that cladding materials have recently generated a lot of debate and negative press about how reliable some particular materials are, questions are being asked of the safety and reliability of external wall insulation. However we must clarify that, although external wall insulation can be classified under cladding, it is very different to rainscreen cladding - which caused the Grenfell fire tragedy.

External wall insulation is completely safe. However, when it comes to fire, the safety of your system depends largely on the insulation type in question. The safest type of insulation you can have installed is the Rockwool insulation boards which are rated as Euroclass A1 non-combustible. The board is specially designed in such a way that it contains fire - preventing it from reaching the other areas of the building. They also do not produce harmful emission or smoke when impacted by fire.

Meanwhile, the Wood Fibre, is also a great insulation which is known to char and not burn. Contrary to many beliefs, it actually burns slowly creating this charring effect which produces an oxygen barrier that helps reduce the spread of fire.

To make your system safer, you can also make use of Fibreglass Mesh for reinforcement. It helps to improve the strength of the tensile which promotes the security of the boards attached to the wall.

Damp issues on a property are usually generated by a lot of factors such as a poor or broken guttering, condensation and lots more. The question arising here is what is the possibility of External Wall Insulation (EWI) preventing condensation? Not only is EWI a reliable way to reduce condensation-caused damp, but it’s also one of the major reasons property owners in solid wall homes consider thermally rendering or cladding their external walls.

Condensation arises as a result of warm moist internal air hitting a cold surface such as the steaming up of both windows and mirror when having a shower. What happens here is the condensation of the water vapour in the air from a gas to liquid in the process of touching the cold surface - one whose temperature is significantly reduced to reach the dew point. At the dew point, condensation is very rampant, and to tackle this issue you’ll have to heighten the wall temperature in order to convert the moisture to vapour and permit it to pass through the wall. And that’s exactly the job of an external wall insulation!

To get started you must ensure that the walls are clean and dry prior to fitting the external wall insulation. The month of May through to September when the weather tends to be dry and more stable are usually the best period to carry out the project. The external wall insulation will function just like a cosy blanket around the building. Ultimately, changing the feel and temperature of the inside of your home. As a result, the previously cold walls will no longer be cold which goes a long way to mitigate the effects of condensation. Furthermore, when an EWI is installed, the rooms of your home will automatically trap more thermal mass as the heat is saved in the walls’ fabric and released back when the temperature drops.