Basalt Wool Vs. Polystyrene

Basalt vs. polystyrene wool: Know the differences

Thermal insulation is needed both to contain the heat inside buildings and to produce thermal protection. In fact, it protects indoor environments from both winter cold and summer heat. You can choose many materials to achieve this result. Basalt wool and polystyrene are excellent two options among them.

Both make it possible to achieve comfort and achieve significant energy savings. It is interesting to make a comparison between these two types of insulation.

In this article, we analyze the most debated topic: basalt wool vs. polystyrene. We will try to cover the respective characteristics of these materials to find out what is best for you.

What is basalt wool?

Basalt wool is a ball of mineral wool. It is a soundproofing and thermal insulating material. It is one of the best materials used in construction to protect the building from heat, cold and noise.

It is a natural product, such as cork and glass wool, which allows insulation without chemical elements. It is very easy to use and it is easy to adapt to any situation and any possible shape. But some care must be used in the installation.

Basalt wool has many competitive materials, such as polystyrene, polyurethane, polyvinyl and phenolic resins. However, it manages to stay at the top of the market for some peculiarities that distinguish it.

In addition to being of natural origin, it cannot be attacked by insects of any kind and remains unchanged over time.

What is polystyrene?

Expanded polystyrene has been very successful, mainly due to its practicality of use. Since its first appearance on the market as an insulating material, it is on top. In construction, it is one of the most important materials for insulating structures, mainly vertical.

In fact, it can be installed with very large boards. They are excellent for thermal insulation of the perimeter walls of reinforced concrete structures.

Expanded polystyrene self-extinguishes. In the event of a fire, it self-destructs due to the high percentage of air inside. It is easy to cut with sharp blades or an electric saw.

It is not difficult to assemble, as it can be broken with your hands without any danger to health.

Basalt wool vs. polystyrene: the difference

Here we will briefly discuss both basal wool and polystyrene, so that it becomes easier for you to understand the difference between the two.

Basalt wool: mineral and ecological insulation for all types of support

It is made of rock, which comes from volcanic activity. Basalt wool: it is a natural and non-polluting 100% material. Entirely environmentally friendly, this insulation poses no health hazard and can be recycled safely. It is used in the construction and renovation of buildings for its excellent thermal and sound properties.

The advantage of B ASALT W OOL

I ts hydrophilic and non-combustible characteristics. We should also note its invulnerability to termites and moisture. In terms of lifespan, it is about fifty years.

Basalt wool can be placed in several thicknesses to optimize performance. The thickness will be chosen according to the thermal resistance and the type of surface to be insulated:

  • Attic
  • walls
  • plating
  • Roof terrace or
  • crawl

Wool rollers, however, lose their consistency over time, especially when used to insulate attics.

Import ance

Always investigate the thermal conductivity of the product as it will affect the thickness calculation for optimal insulation. The lower the coefficient, the more effective the insulation will be. Do not forget to take into account the climatic characteristics of the region.


Basalt wool is sold in rolls, panels or in bulk. Its price is about 10 $ per square meter for wool in panels or rolls and about 2 5 $ per kg for bulk wool. As an indication, it takes an average of 4 liters of 75 mm or 15 liters of 300 mm to cover one square meter of surface. In your budget, install a back wall to insulate the panel or roller.

Polystyrene: Not very environmentally friendly, but with excellent thermal performance

Polystyrene, on the other hand, is an organic insulator obtained from oil. It is a polluting material that is not based on bio. In addition, the treatment and transformation of the material requires a large amount of energy. In fact, it is responsible for greenhouse gas emissions.

Due to its chemical composition, polystyrene is not very resistant to fire. It also does not offer soundproofing properties, unlike basalt wool.

Not very suitable for old houses. It is non-breathable and not very hydrophilic insulation, which is preferred for concrete houses. It should be noted that its implementation on the facade requires the joint use of basalt wool. This is necessary to comply with fire regulations.

The advantages of polystyrene

Polystyrene is known for its very good insulating qualities, as its thermal conductivity is low. It is ideal for insulating exterior walls, low floors, roof spaces and roofs. Lightness, ease of installation, resistance to compression and impermeability to water vapor: these are also the main advantages of polystyrene. Its lifespan is over 50 years.

Types of polystyrene

This insulation is available in two families: expanded polystyrene and extruded polystyrene. The best insulation performance is attributed to the latter due to its density. Its density per cubic meter is twice that of expanded polystyrene.


Polystyrene is generally sold in packaging. The price is relatively affordable, around USD 8.50, without taxes per square meter for expanded polystyrene. It is 10 $ - 11.00 $, without taxes per square meter for graphitized polystyrene. (Graphitized polystyrene: a derivative of expanded polystyrene that provides better thermal performance).

The price depends on the thickness and format. On the other hand, it is necessary to provide for about fifteen euros or more per square meter of extruded polystyrene.

Basal Comparison Table Wool Vs. polystyrene

Isolating Basalt wool polystyrene
Weight Comparatively, a little hard Light
Moisture R esistance Non-hygroscopic and water resistant Relatively low water resistance
Breathability Very breathable nonrespirable
Fire resistant Fire resistant It must be combined with basalt wool to be fireproof
Insulation Excellent Relatively low
Ease I Installation Difficult Easy
Medium E ffect Ecological and non-polluting Pollutant / produces greenhouse gases.
Price Expensive Cost efficient

BAZALTIC wool vs. Polystyrene: Which is better?

Let's go to the parts.

One of the most important scores is the insulation coefficient; only this reflective insulation exceeds it in this section. With XPS, it connects.

In terms of price, basalt wool is slightly expensive.

We can conclude that the only disadvantage of basalt wool is the possibility of leaks on the facade and a slightly more difficult installation than polystyrene. If we take the necessary care to seal the windows well, I think basalt wool is the best solution.

The final verdict

In recent years, the importance of thermal insulation has become increasingly important. Especially when it comes to the issue of energy consumption, it is very important and convenient to think about insulation works in the case of renovation works.

In this analysis, we wanted to make a special comparison: basalt wool vs. polystyrene It is a recurring question about which of the two is better. We have already seen in the analysis for each application, one or the other will behave a little better than the other. But if we talk only about the insulating capacity for the same thickness, basalt wool exceeds extruded polystyrene.

Leave a comment