When starting an energy renovation or house construction, one of the most common questions from investors is: "Should we put styrofoam EPS or rock wool?"
The fact is that styrofoam is initially a cheaper material. However, a facade is not made for one or two seasons; it is made once in 30 years. When you divide that cost over decades of use, the price difference becomes negligible, and the difference in quality of life – huge.
At 2LMF PRO we always advise clients to look long-term. Here are 3 key reasons why rock wool is a superior choice for your home.
1. Safety first: Wool does not burn!
This is argument number one. Rock wool belongs to non-combustibility class A1. It is produced from volcanic rocks (basalt) and melts at temperatures above 1000°C.
In case of fire, styrofoam melts and can emit smoke, while rock wool acts as a fire barrier that prevents the spread of fire. When you dress a house in wool, you've literally put a firefighter suit on it.
2. "The house must breathe" (Vapor permeability)
You often hear the expression that a house must "breathe". This doesn't mean the wind blows through the walls, but that moisture from the interior can go out.
- Styrofoam EPS is vapor-impermeable. It closes the house similar to a plastic bag. If ventilation is not perfect, that moisture stays inside and creates ideal conditions for fungi and mold.
- Rock wool is highly vapor-permeable. It allows moisture to pass through the wall and go out, which drastically reduces the risk of condensation.
3. Sound insulation and durability
Styrofoam is a very light material and a poor sound insulator. Rock wool is dense, fibrous and heavy. It physically "absorbs" sound waves, creating an oasis of peace in your home.
| Characteristic | Styrofoam EPS | Rock Wool |
|---|---|---|
| Fire resistance | Burns (E class) | Non-combustible (A1 class) |
| Vapor permeability | Low | High (Wall breathes) |
| Sound insulation | Weak | Excellent |
Conclusion
A rock wool facade is an initially more expensive investment, but it offers safety, a healthier microclimate and peace. If you are building a house for yourself and your family, rock wool is the only uncompromising choice.
Need advice on choosing the best insulation for your home?
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