Rockwool Insualtion 

Rockwool insulation , or mineral wool insulation is one of the major insulation types commonly used in residential and commercial buildings in North America. It is called rock wool for two reasons. First, it is derived from a kind of rock  called basalt rock, also known as volcanic rock, since most but not all volcanic rock is basalt rock. Basalt rock is formed from fast cooling lava of volcanos. The other reason mineral wool insulation is thus called is because of the structure of basalt rock. Because the skeins of lave cool so quickly during formation, basalt rock has lattice like structure, imagine crisscrosses of filaments. Mineral wool insulation itself is made in an industrial process. The basalt rock is heated until it liquefies. It is then cooled and spun, drawing out the strands of the latticework in the rock into a wool-like material. Rockwool insulation looks similar to fiberglass insulation, thick sheets of a dense woolly material, but is much denser. It also comes in the same shapes as fiberglass insulation, with batts being a very common form. 

Though similar in appearance to fiberglass insulation, there are important differences between the two insulation types that would lead one to choose rockwool over fiberglass. One major benefit of rockwool insulation is that it is made mostly of recycled materials, whereas fiberglass is completely synthetic. Less synthetic materials can mean less stress on the environment. Rockwool is also naturally fire-resistant; there is no need to add chemicals to it to make it so. In addition to being fire-resistant, rockwool is also water resistant. It actively repels water. Along with it's water resistance, rockwool also is mold resistant. Mold needs three things to grow, food, water, and warmth. Mold cannot eat rockwool because mold doesn't eat rock and there's no water for it to establish itself either. Because of it's structure it is also good at lessening sound. The sound waves get caught in its dense structure and has trouble transmitting further. Rockwool also degrades very slowly because it is made of organic rock. It also has a higher R-value than fiberglass, about 30% higher in fact, and it is three times denser.

There are of course downsides to rockwool insulation. One is cost. Fiberglass is by far the cheapest insulation type, followed closely by cellulose and natural fibers like denim etc. While it isn't as expensive to install as spray foam, there is definitely a premium to be paid for its superior benefits. Because it is made of rock, really the only way for it to break down is mechanically. It is not at all biodegradable and this can be a disadvantage if insulation isn't recycled. It's density makes heavier than other insulation types and trickier to install. More precautions must be taken during installation as well. Rockwool is made of this strands of material and as such can irritate the skin and airways. During installation proper protective equipment must be worn like heavy gloves and a mask. Another disadvantage could be that volatile organic compounds could be used to hold the fibers together. It's important to ensure that the rockwool type chosen makes it explicit that  VOCs are not used in the product.