Vermiculite: The Multipurpose Mineral for Your Home

Vermiculite is a mineral from the mica family that, when subjected to high temperatures, undergoes an expansion process (exfoliation). The result is an incredibly lightweight, non-combustible material with extraordinary insulating properties.

Why use it in construction?

Unlike common gravel, vermiculite offers specific advantages for renovation and energy efficiency projects:

• Extreme Lightness: Ideal for creating screeds that do not overload old floors or ceilings.
• Thermal and Acoustic Insulation: Drastically reduces heat loss and dampens impact noise.
• Fire Resistance: It is a Class A1 fireproof material, used for the passive protection of flues and metal structures.
• Breathability: Promotes vapor passage, preventing the formation of mold and condensation.

Dosage for a Lightweight Screed

To obtain an insulating and lightweight sub-base, the recommended ratio is generally:

• 1 part Cement
• 3-4 parts Expanded vermiculite
• Water as needed (until a "damp earth" consistency is achieved)

Pro tip: Vermiculite tends to absorb a lot of water. It is important to wet the mix well but without overdoing it, to prevent the cement from sinking to the bottom of the pour.