1 - Wall treated with primer
2 - IGK2
3 - 160 g mesh
4 - IGK2
5 - Primer
6 - Finish coat
The definitive guide to choosing the thermal insulation that lets your home breathe
Effective thermal insulation is not only measured by the ability to retain heat or cool. Breathability is the fundamental characteristic that allows the walls of your home to “breathe”, guaranteeing comfort, healthiness and durability over time. Choosing the right material means protecting the building from humidity, condensation and the formation of mould, while achieving maximum energy savings.
In this guide, we explore everything you need to know about breathability, compare traditional insulation materials, and discover the innovations that are revolutionizing the industry.
What is Breathability and Why is it So Important?
Breathability (or water vapor permeability) is the ability of a material to let water vapor present in the internal air of the rooms pass through it, allowing it to migrate outwards without condensing inside the wall. This property is measured by two key values:
µ value (mu)
Indicates the resistance to the passage of steam. A low µ value means that the material is highly breathable. For example, air has µ=1, while many building materials have higher values.
Sd value
It is the product of the µ value and the thickness of the material (expressed in metres). Represents the total resistance of the layer. A well-designed stratigraphy requires that the Sd value decreases from the inside to the outside, facilitating the escape of the steam.
Attention!
A non-breathable thermal coat (with high µ) can block internal humidity, leading to:
- Formation of interstitial condensation inside the wall.
- Growth of mold and algae.
- Deterioration of materials and loss of thermal performance.
- Poor indoor air quality, with possible repercussions on health.
The Most Popular Insulating Materials: An Overview of Breathability
The market offers different types of insulation, each with well-defined breathability characteristics. Here is a description of the most common.
EPS (Expanded Polystyrene) Economical and lightweight synthetic insulation. It has low breathability (µ value around 50). The graphite version improves thermal performance. Recommended use: perimeter walls in climates that are not excessively humid, where budget is a priority.
XPS (Extruded Polystyrene) Synthetic insulation highly resistant to water and humidity. It has very low or no breathability (µ value can reach 200). Recommended use: plinths, foundations, basements and areas in direct contact with the ground or water.
Rock wool Highly breathable mineral insulation (low µ). It also offers excellent fire resistance and good sound insulation. Recommended use: ventilated roofs, walls in cold or humid climates, and wherever maximum fire safety and vapor management is required.
Glass wool Mineral insulation with medium breathability. It is light and offers good acoustic comfort. Recommended use: insulation of attics, false ceilings and internal walls in combination with appropriate vapor barriers.
Wood Fibre Highly breathable natural insulation (low µ). It contributes to an excellent thermal phase shift, keeping it cool in summer. Recommended use: redevelopments of historic buildings, wooden or masonry walls that require maximum breathability and summer comfort.
Cork Highly breathable natural insulation (µ value approximately 15). It is also flame retardant, elastic and moisture resistant. Recommended use: indoors and outdoors in variable climate zones, ideal for those looking for an ecological material with complete performance.
Polyurethane (PIR/PUR) Synthetic insulation with very high thermal efficiency for the same thickness. It has low breathability. Recommended use: when the available thicknesses are very reduced (e.g. renovations of balconies, unusable attics).
Overcoming Challenges: Towards a New Era of Thermal Insulation
If you are looking for a material that overcomes the traditional compromise between breathability, thickness and other performance, discover the nanotechnological solution presented at the bottom of the page.
Comparison Table: Strengths, Defects and Final Choice
Choosing the right material depends on a balance between performance, budget and specific context. This table summarizes the key points to help you decide.
EPS Low cost, lightweight, easy to install. Flaws: low breathability, sensitive to UV rays, flammable if untreated. Where it is recommended: standard residential buildings in dry climates, interventions with limited budget.
XPS High resistance to water and compression. Defects: zero breathability, higher cost than EPS, environmental impact in disposal. Where it is recommended: plinths, foundations, basements, inverted flat roofs.
Rock wool High breathability, non-combustible, excellent sound absorbent. Flaws: high weight, can absorb humidity if not protected, medium-high cost. Where it is recommended: ventilated roofs, perimeter walls in humid or cold areas, buildings at risk of fire.
Glass Wool Good cost-performance ratio, light, good acoustic insulation. Flaws: medium breathability, may irritate during installation. Where it is recommended: insulation of attics, unusable attics, internal walls.
Wood Fibre High breathability, excellent thermal inertia (summer comfort), natural material. Defects: high cost, greater thicknesses for the same thermal performance, sensitive to water. Where it is recommended: green building, valuable redevelopments, wooden walls or traditional masonry.
Cork High breathability, natural, elastic, fire retardant, resistant to insects and mold. Disadvantages: very high cost. Where it is recommended: interiors (plasters, substrates), prestigious facades, environments with hygiene and health requirements.
Polyurethane (PIR) Best lambda (insulator with the same thickness), light, stable. Disadvantages: low breathability, high cost, emissions in case of fire. Where it is recommended: where space is critical: attics, curved roofs, technical spaces.
Innovation
The Evolution of the Sector: New Technologies Based on Nanotechnology
Technological progress has led to the development of innovative solutions that overcome many limitations of traditional materials. Today, nanotechnologies make it possible to create products that combine previously irreconcilable performances:
- Highly breathable for a healthy indoor climate.
- Water-repellent to protect from pouring rain.
- Fireproof to increase safety.
- Anti-mold and self-healing.
- Eco-friendly, water-based and low-emission. These solutions no longer require the installation of bulky panels, but are applied as very high performance plasters or smoothing compounds.
EcoNanoTherm IGK2: A Concrete Example of Revolution based on NanoTechnology.
EcoNanoTherm IGK2 is a perfect example of this new generation of insulation. It is a premixed heat-insulating paste that incorporates silicon nanomolecules.
Quick and clean application
It spreads like normal plaster, without the need for panels, plugs or invasive and noisy operations.
Exceptional performance
A layer of a few millimeters is equivalent, in terms of insulation, to many centimeters of traditional materials.
Breathable and ecological
The product is breathable and water-based, allowing the walls to breathe and combating the formation of mould, with maximum respect for the environment and healthy living spaces.
To discover all the technical details, tax advantages and methods of application of this revolutionary solution, visit the dedicated page: EcoNanoTherm IGK2 - The revolution in thermal insulation.
Conclusions
Choosing the material for your thermal coat is an important decision because it affects the comfort, management costs and health of your home for the next decades. Traditional materials remain options to consider for specific contexts, new nanotechnological technologies such as EcoNanoTherm IGK2 represent an extraordinary step forward. New nanotechnological technologies such as EcoNanoTherm IGK2 offer:
- superior performance
- drastically reduced production times
- optimal management of breathability Assess your needs, consult a professional and don’t be afraid to explore the innovations that the market offers. Investing in smart, breathable insulation is the best way to protect the value of your home and the well-being of those who live there.
FAQ (Frequently Asked Questions)
What is the difference between µ and Sd?
The µ measures the material’s resistance to the passage of vapor, while Sd indicates the total resistance of the layer taking into account the thickness.
Does a breathable coat eliminate mold?
It reduces the risk because it facilitates the release of steam, but correct installation and adequate ventilation are also needed.
What is the most breathable insulation?
Among common materials, rock wool, wood fiber and cork have the most favorable breathability values.
Are nanotechnological solutions really effective?
Yes, because they combine high breathability with reduced thicknesses and properties such as water repellency and fire resistance.