Why you should use Rockwool Insulation

If you’re considering a remodel or an addition to your home you will have to have a discussion on how to insulate the walls. There are a few different materials you can use and if you walk through Home Depot or Menards you can see all kinds of pink insulation and other brands as well, however, you might want to call a spray foam insulation installer.. One material that is growing in popularity is Rockwool – which like the name suggests is wool made from molten rock. A mixture of basalt, anorthosite, and cemented briquettes are heated up in excess of 1500 degrees at which the rock mixture becomes molten and this is then spun into fibres. A binder and mineral oil are then added which stabilises the spun rock wool fibres and also makes them water repellant.

Rockwool insulationRockwool is comparable with EPS in terms of its insulating ability, but there are a few reasons why architects often specify it when they are designing builds.

Rockwool is breathable allowing moisture to escape from the building process.  This reduces the risk of mold ab=nd bacteria growth coming from the inside the home.

Rockwool is very easy to install and it provides airtight seals to the building.  This has become more and more important during today’s construction process.  

Because rockwool is a natural product and slightly manufactured the longevity of this product is off the charts.  Rockwool is not going to break down like other insulations commonly used.  Insulation breaks down from the air quality and fluctuations in moisture.

If you enjoy telling friends and family that you have a low carbon footprint to the planet, telling them you have Rockwool insulation would rise to the top of the list. This is a big deal as Rockwool reduces the non-renewable energy sources such as gas and electricity to air pollution. 

The ease of installation was the deciding factor for me.  The grey material is easy to cut and doesn’t leave all that itchy fiberglass fiber on your skin.  This material also has a sound proof quality to it but I think that may work better if you had 6” wall framing instead 4” as I don’t notice any sound barrier improvement.

Rockwool insulation has a certain amount of recycled material which is derived from the steel slag.  Rockwool products contain between 16% or 40% pre-consumer recycled material.


When comparing the cost of fiberglass insulation to the cost of Rockwool will vary from location and quantity but as a general rule of thumb, Rockwool will cost approximately 30% more per batt.  So Rockwool is a little pricey but well worth the expense.  If you live in Wisconsin Rockwool is the way to go and you can buy Rockwool at Home Depot.