More and more homeowners plan to insulate the exterior walls of their buildings. This work offers many advantages, not to mention thermal comfort and optimal reduction of energy loss.
However, it must be admitted that the cost of the project is significant. Especially since the task will be entrusted to professionals. Fortunately, it seems quite feasible to handle the insulation yourself.
If you are thinking of starting this project, this article serves as a guide to help you choose the right method and necessary supplies. Before going into details, it is important to first explain the benefits of external insulation.
📋 Key points: Personally, I consider it possible to insulate an exterior wall yourself, but only with accessible techniques like insulating panels or glued polystyrene. However, complex systems like ETICS under render often require a professional. Poor installation can reduce thermal efficiency by up to 30%. Choosing the right method is therefore essential.
Good reasons to insulate an exterior wall
👍 Advantages
- Labor cost savings
- Thermal improvement
- Property value enhancement
👎 Limitations
- Sometimes complex techniques
- Risk of thermal errors
- Challenging finishing
Whether you plan to do it yourself or prefer specialists to intervene, the work always involves significant expenses. In any case, the project represents a profitable investment. Discover the advantages of insulating a wall.
🗣️ My experience: I tried to insulate a small garage wall with expanded polystyrene panels. The installation seemed simple, but I had poorly prepared the surface, which created thermal bridges. I had to start all over. The lesson: preparing the wall is as important as the insulation itself.
Reducing energy loss
In a house, heat loss occurs at windows, floors, roof, and especially walls. The latter are among the structures of a home that require good insulation.
To do this, simply insert an insulation layer on the exterior surfaces. This material significantly limits air flows inside the house and energy loss.
Heat no longer escapes through the building envelope. Even better, this eliminates thermal bridges. Thanks to this, insulating a wall greatly reduces the electricity bill. It limits the need for cooling as well as heating.
To go deeper, I recommend best exterior insulation which compares the methods. interior insulation cost also provides useful benchmarks. And to go further, exterior cladding offers additional insight.
Improving comfort at home
If you want to increase thermal comfort at home, consider insulating your exterior wall. The work helps maintain pleasant temperatures, whatever the season. In winter, you gain about 2.5 additional degrees.
Say goodbye to constant cold sensations. Cold surfaces will disappear. The integrated insulation layer manages to eliminate them.
💡 Practical tip
Always check the condition of the wall (cracks, moisture) before installing exterior insulation to ensure optimal effectiveness.
Enhancing the house
Even if exterior insulation can cost a fortune, it allows you to rejuvenate the exterior appearance of your property. To carry it out, there are many techniques. Whatever the method applied, it beautifies your house.
The work gives you the opportunity to renovate the envelope of your home. Cladding or rendering, the finish provides a better look dressing the dwelling.
That’s not all, if you practice exterior insulation, you surely improve the energy rating of the building.
It should be recalled that the Energy Performance Diagnosis or DPE is now required for a rental or sale project. So if you plan to insulate the walls from the outside, you certainly enhance your real estate.
Choosing the right wall insulation technique
| Method | Difficulty | Average cost | DIY possible |
|---|---|---|---|
| Bonded panels | Medium | 20–40 €/m² | Yes |
| Insulating render | Difficult | 40–80 €/m² | Not recommended |
| Cladding + insulation | High | 60–120 €/m² | Partially |
| Insulation under framework | Very high | 80–150 €/m² | No |
If you plan to insulate a wall yourself, you must master a number of details. It remains essential to know the different possible methods.
Carrying out insulation with render
🌍 Did you know?
Poor wall insulation can account for up to 25% of a home’s heat loss.
This technique involves applying a thermal insulation layer on the exterior masonry. Once done, you wrap them with a finishing render.
It is the ideal method to eliminate thermal bridges. It is more than sufficient to meet the criteria of the Thermal Regulation 2012 or RT 2012.
There are two approaches to applying the coating. Direct application is the simplest method. It involves applying the bonding agent, the insulating mortar, and the finishing coat.
You can also opt for installing insulating panels. Like the previous technique, it starts with applying the bonding agent.
The next step is to install the panels that provide insulation. That said, the final phase aims to apply the finishing layer.
There are many categories of insulating coatings dedicated to insulating an exterior wall. When the owner prefers not to use a professional’s services, they can use them without any problem.
Among the most used materials, hemp plaster, cob, silica aerogel, and lime-cork render offer remarkable effectiveness.
Opting for cladding
Installing cladding is one of the best ways to effectively insulate an exterior wall. It helps reduce heat loss and provides good acoustic and thermal insulation.
This technique involves installing a frame on the exterior surfaces. Before covering the insulating panels with cladding, they must first be placed over the wall.
You can use various materials such as traditional wood, composites, wood panels, metal, terracotta, PVC, and much more.
To carry out insulation with cladding yourself, it is important to follow certain steps such as the base, then marking, the placement of angles, and that of the insulation wool.
The first involves treating the lower part of the wall by applying a specific coating 20 cm high.
Next, you mark the reference points to define the area. Remember to drive a concrete nail to attach the chalk line. Once the marking is finished, place the angles. If you complete the previous steps, you will have no difficulty fixing the glass wool.
Insulation under cladding is particularly suitable for damp or damaged facades. Even though it is more expensive than the under-coating technique, it manages to remedy the defects of exterior walls.
⚠️ Common mistake
Applying insulation directly on a damp wall is a classic mistake. Trapped moisture greatly reduces thermal performance and can cause mold.
Calling on a specialized craftsman
Although it is still possible to handle exterior insulation yourself, hiring a qualified technician is not a bad idea either.
As we keep reminding you, these works can be costly. The average price of insulation under coating ranges between €110 and €180 per square meter. As for insulation under cladding, this project requires a budget between €140 and €230 per square meter.
If you entrust the work to a RGE certified craftsman, you can benefit from numerous financial aids. With Ma Prime Rénov, you have the possibility to collect up to €75 per square meter depending on your income.
Besides that, there is the Prime Effy, the zero-interest eco loan, and the VAT which is reduced to 5.5%. This discount will be directly applied to your invoice by the RGE professional.
Can you insulate an exterior wall yourself?
Yes, some simple methods like insulating panels can be done yourself, but complex systems require a professional.
What is the simplest method of exterior insulation?
Glued insulating panels are the most accessible for a beginner DIYer.
What are the risks of poor exterior insulation?
Poor installation can lead to thermal bridges, heat loss, and moisture problems.
