Thermal Insulation Materials: 4 Categories

Mineral wools: effective and inexpensive thermal insulation materials

Mineral wool is the first major family of insulation materials used in the building industry.

It is inexpensive and has the advantage of being thermally and acoustically efficient. For all these reasons, it is often selected for building or renovating a building.

However, it presents some disadvantages: it is sensitive to humidity and increases indoor pollution. Moreover, it is not compatible with ecological criteria...

Three categories of mineral wools can be identified:

• Glass wool is the most common. It is made from sand and recycled glass. It is generally presented in the form of a roll or a mattress made up of interweaved fibres.
• Rock wool is made from a volcanic rock, basalt. It is very versatile and can be found in the form of panels, rolls or flakes.
• Cellular glass is a kind of solid foam made of sand and recycled glass (iron oxide or sodium sulphate is added to these basic elements before baking). The end result is an insulation with a closed cell structure (hermetically sealed glass cells). It is possible to find it in the form of panels, sheets or blocks.

Vegetal wools: for environmentally friendly winters

The second major family of insulating materials is vegetal wools, which are fully bio-based thermal insulators.

They offer much greater ecological and sustainable advantages than mineral wools, with varying costs depending on the material (straw, for example, is very cheap, but requires more available space).

Examples of vegetal-based materials for insulation:

• Cork has long been chosen for its natural sound insulation properties. If it is agglomerated or expanded cork, which has therefore been processed, it can be an interesting thermal insulator.
• Wood fibre, in the form of panels, felts or flakes, is easier to use than glass or rock wool, for similar thermal performance.
• Less well known, wood wool obtained from bound wood chips is also interesting.
• Cotton wool, flax wool and cellulose wadding, combined with synthetic materials, can also be good alternatives.
• Eventually, for those who want to play the ecological card, straw, obviously dried and compacted, has entered the field of thermal insulation materials.

Animal wools added to synthetic materials

The third major family is made up of animal wool-based insulation materials.

Animal wool is not easily inflammable and is interesting because it regulates humidity. However, sheep or goat wool, which can be found in rolls or panels, must first be treated with fungicides, insecticides and fire retardants before being used.

This is the case with sheep's wool, which is then sold in rolls or boards.

Thin and synthetic materials, for additional insulation

To conclude this overview, we should mention “thin” insulators, composed of layers of aluminium foil interspersed with layers of felt. These are called “back-up” insulations, as their quality varies according to their thickness. You might as well choose a high-performance insulation from the outset...

Finally, there is synthetic insulation in the form of rigid panels, such as polystyrene panels. Again, this is preferable for correction or reinforcement work.

In short, you get the idea, finding the right thermal insulation material for your building project will depend above all on your objectives, your needs and your budget. For example, for high technical performance and low cost, mineral wools are the best choice. However, if you prefer to avoid irritating materials, choose animal wool (which is generally more expensive). If ecology is important to you, choose vegetable wools (whose price varies greatly depending on the material). Finally, for reinforcement work, opt for thin and synthetic insulation!