Thermal insulation materials
Thermal insulation of buildings
Thermal insulation of buildings is essential to ensure living comfort.
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Thermally insulating a building means implementing all the necessary interventions to limit the heat flow between the external and internal environment. These interventions, which involve the insertion of insulating materials, mainly concern opaque surfaces, i.e. vertical structures, intermediate horizontal structures and horizontal roof structures.
Ensuring high levels of well-being must be the designer's goal regardless of whether it is a new construction or redevelopment work on existing buildings.
Standards of Reference
The UNI ISO EN 7730:2006 standard (Ergonomics of thermal environments – Analytical determination and interpretation of thermal comfort through the calculation of PMV and PPD indices and local thermal comfort criteria) defines the individual's thermo-hygrometric well-being as "the mental condition of satisfaction with the thermal environment".
Individual well-being clearly depends on some subjective and therefore non-quantifiable factors, and on other factors external to the individual and therefore quantifiable (for example, temperature or humidity).
To ensure the right thermo-hygrometric conditions inside an environment, each part of the envelope must be carefully designed to avoid the presence of thermal bridges, and the right insulating materials must be carefully chosen.
Design solutions
The design solution can never be unique and adaptable for each building.
In fact, several factors must be considered:
- reference climatic context
- type of intervention (new building or existing building)
- intended use (public or private)
- economic availability
Once the above factors have been defined, we can study the right stratigraphy to be created or the interventions necessary to guarantee the thermal insulation of the envelope.
The insulation of vertical opaque structures can be performed both from the external side of the wall and from the internal side.
External insulation involves the creation of thermal coats, ventilated walls or the application of insulating plasters. Clearly, interventions like these will not modify the available internal space but require a workmanlike installation.
Insulation from the inside, instead, consists of “lining” the wall with insulating panels. Obviously, by acting from the inside, adding an additional layer to the wall, the space will be resized.
If the building is made with a cavity, you can consider blown-in insulation, already discussed here: https://www.archweb.com/coibentazione-tramite-insufflaggio/
Insulating materials: types
When choosing an insulating material, it is obviously necessary to take into account some parameters. The most important is obviously the thermal conductivity λ [W/mK]. Thermal conductivity expresses the capacity of the material to transmit heat. Low values of λ indicate a material with
There are different types of insulating materials on the market. They can be distinguished according to their origin. In particular, we can group them into three macro categories:
- Materials of natural origin
- Materials of mineral origin
- Materials of synthetic origin
Natural origin materials
Natural materials are mainly of vegetal origin. They come from raw and renewable materials. They have production and installation processes that are not harmful to humans. They are generally used for external coats, insulation of internal walls, insulation of attics and being non-toxic also for the insulation of internal walls.
Fall into this category:
- Wood fiber
- Hemp fiber
- Cellulose fiber
- Cork panels
- Jute Fiber Panels
- Flax fiber
- Corn fiber
- Coconut fiber
Materials of mineral origin
Mineral materials are the most common in construction. They are obtained from the processing of rocks and their use depends on their composition and structure (fibrous, alveolar, cellular).
Generally, coats, ventilated facades, false ceilings and attics are used.
Fall into this category:
- Fiberglass
- Rock wool
- Expanded clay
- Expanded perlite
- Felts
Materials of synthetic origin
Synthetic materials have been and in part still are widely used in construction. Unfortunately, many studies in recent years have shown how the use of such materials is harmful to the environment, to humans and above all presents high recycling difficulties. Therefore, today where greater attention to the environment is not only a choice but also an obligation, other types of insulating materials are to be preferred.
Fall into this category:
- EPS Expanded Polystyrene
- XPS Extruded polystyrene foam
- Polyurethane
- Reflective rolls
Commercial formats
The various insulating materials are available on the market in different formats.
- Panels: they can be rigid or semi-rigid to be fixed to the support
- Rolls: generally placed in cavities or false ceilings
- Foam: they are sprayed with suitable equipment into the air chambers
Clearly, the choice of one insulator rather than another also takes into account the available formats and the application methodology.
CAM (Minimum Environmental Criteria)
With the Ministerial Decree of 11/10/2017 the Minimum Environmental Criteria come into force in Italy.
The aim of CAM is to ensure environmental performance above the sector average by rationalising consumption and making buildings more sustainable and efficient.
The decree lists a series of checks that insulating materials must also comply with.
However, there is no CAM certification to be attributed to materials that meet these requirements. It will be enough to look for other types of environmental certifications, such as the EPD (Environmental Product Declaration) certification that certifies the environmental characteristics of the product.
Compliance with CAM is a good indicator and, moreover, it is a requirement for access to tax bonuses.
The cover photo is by kalinovsky on Depositphotos.com
