Mineral wool (also known as Rockwool) is one of the most common insulating materials currently used in the US and Canada. It is made from natural rock and steel slag, a recycled by-product of steel production. 

This insulation material is also very versatile. It can be used to insulate every part of a home, including the roof, walls, and floors. Mineral wool is also sometimes used to insulate the attic, although this application is rarer than the others. 

Rockwool insulation offers several advantages, such as excellent performance in terms of both thermal and noise insulation. It is also quite durable and resistant to fire, mold, mildew, etc.

The only disadvantages of Rockwool are that it is not biodegradable and can be slightly more expensive than similar insulating materials like fiberglass and cellulose. 

Moisture Resistant

Rockwool actually repels water, and won’t absorb moisture like its competitors. This keeps your insulation spaces dryer, and prevents degradation of the adjoining construction material.

Density

Rockwool effectively reduces airflow and essentially, sound transmissions. Its higher air flow resistivity means better sound attenuation for a quieter environment.

R-Values

For the same thickness, Rockwool provides a higher R-value, or for a given target R-value, you can use a less thick Rockwool batt choice, making installation less expensive.