Materials: Thick insulation, best choice or net loss
Hi, this is Claude. Opting for thick insulation can boost your home’s thermal performance, but be careful not to confuse thickness with actual efficiency: it’s the balance between thermal conductivity and thickness that makes the real energy savings. Thicker insulation limits heat loss, but only if you choose the right material to maximize long-term energy savings. The complexity doesn’t just lie in the thickness, but in the way the material plays with thermal conductivity and integrates into your home.
- Assess the area to be insulated to determine the necessary thickness.
- Opt for insulation with low thermal conductivity, not just thick insulation.
- Consult the guide to find out about the best insulating materials.
- Check the financial assistance available for high-performance and environmentally friendly materials.
- Plan for professional installation to avoid thermal bridges.
To learn more, read my article on the comparative guide to high-performance insulation materials, or discover a detailed buyer’s guide to insulation which explains how to combine insulation thickness and thermal conductivity at the best price.
Why thick insulation can improve thermal performance
Thick insulation acts as a shield against heat loss, but it’s important to understand that increasing the thickness without considering thermal conductivity risks wasting space unnecessarily. Insulation with low thermal conductivity allows for… energy efficiency higher even with a moderate thickness. But if you can afford the thickness, the gains in thermal comfort and savings are often impressive.
An anecdote: a homeowner in Lyon added 30 cm of rock wool insulation to his attic, reducing his heating bill by 25%. The secret? The sufficient thickness provided by low-conductivity insulation allowed him to stabilize the internal temperature in both winter and summer.
Insulation thickness: not always synonymous with the best insulation choice
Very thick insulation is only attractive if its thermal conductivity is relatively low. For example, glass wool with a lambda value around 0.035 W/(m·K) will need a considerable thickness to achieve sufficient thermal resistance, while polyurethane with a lambda value of 0.024 W/(m·K) will offer the same resistance with less material.
If it’s an older home with thick walls, a bio-based insulation with good thermal lag, such as wood fiber, can be an excellent choice for limiting temperature fluctuations. If it’s a city-center apartment with limited space, opt for a high-performance synthetic insulation that is less thick.
Which insulating materials should be prioritized for optimal energy savings?
Eco-friendly materials such as wood fiber, cork, or cellulose wadding are gaining ground thanks to their low carbon footprint and their ability to regulate humidity. This last point is a key, often overlooked element that directly influences the thermal performance over time, preventing premature degradation due to condensation.
| Material | Thermal conductivity (λ W/m·K) | Recommended thickness (cm) | Benefits | Disadvantages |
|---|---|---|---|---|
| Polyurethane | 0.023-0.025 | 16-20 | High performance, low thickness | High carbon footprint, toxic fumes when burned |
| Glass wool | 24-30 | Economical, good fire resistance | May lose effectiveness in humid conditions | |
| Wood fiber | 0.038-0.045 | 28-35 | Ecological, excellent thermal inertia | Expensive, requires fireproofing treatment |
| Expanded cork | 0.037-0.040 | 30-35 | Durable, moisture-regulating, natural | Higher price |
The right choice depends on the available space, regional standards, and the desired environmental impact. comparative analysis of thermal insulation can help to compare these criteria on a daily basis.
3 concrete steps for successful insulation
- Step 1: Measure the surface area and nature of the area to be isolated.
- Step 2: Select an insulation material that is suitable for the available thickness and the desired thermal conductivity.
- Step 3: Ensure a rigorous installation to avoid any loss of performance related to thermal bridges.
Remember: “Choosing the right insulation is also a guarantee of lasting comfort” – a mantra to keep in mind at every stage. With good insulation, you win on several fronts: comfort, energy savings, and respect for the environment.
Is it better to use thick insulation or waste space unnecessarily?
Sometimes, excessively thick insulation reduces living space, impacts natural light, or complicates electrical installations. It is therefore essential to assess whether this extra thickness actually results in significant energy savings.
In some cases, such as small rooms or apartments, thin insulation with a high-performance material may be the most sensible choice. In older houses or those exposed to harsh climates, priority should be given to thick insulation to maintain a stable indoor temperature.
In short, thick insulation is an excellent choice when it meets these three criteria: low thermal conductivity, good thermal inertia, and impeccable installation. Otherwise, you risk a net loss both financially and environmentally.
Why choose insulation with low thermal conductivity?
Because a material with low thermal conductivity better slows down heat transfer, thus improving thermal performance without necessarily increasing thickness.
Does greater thickness always mean better insulation?
Not necessarily. Thickness alone is not enough; it is the combination with good thermal conductivity and careful installation that guarantees a good result.
Which insulating materials should be prioritized for an eco-friendly renovation?
Bio-based insulation materials such as wood fiber or cork are preferable for their low carbon impact and their ability to regulate indoor humidity.
How to avoid losses related to thermal bridges?
By ensuring professional installation, using appropriate vapor barriers and ensuring airtightness so as not to compromise thermal resistance.
What are the advantages of thick insulation in cold regions?
It greatly limits heat loss, stabilizes the indoor temperature in winter, while protecting against summer overheating thanks to good thermal inertia.
Thank you for your interest; Claude
