Home Depot and Lowe's each sell several types and sizes of Roxul insulation, as of August 2015. Both retailers offer Roxul products online and in local stores. In addition, the sellers' sites have user reviews and ratings.
Roxul insulation is made from stone, and this gives it several useful qualities. It absorbs sound well. Because Roxul is fire-resistant, it helps slow the spread of fire. It does not give off toxic gases or smoke in the presence of significant heat.
The insulation is a water repellent that does not lose its shape when exposed to water and moisture. In addition, the insulation resists mold and fungus growth.