Nature and Biodiversity

This insulation is made from stone, and repels fire and water

Hawaii Volcano Observatory (HVO) geologists walk over the surface of a lava flow from the Kilauea Volcano to track surface breakouts near the village of Pahoa, Hawaii October 22, 2014.  The lava began flowing from the Kilauea Volcano on June 27 and as of October 24 the flow front was 0.7 miles (1.2 km) from Pahoa Village Road, according to the U.S. Geological Survey.  About 4,000 people overall live in the residential communities that the lava is approaching. Picture taken October 22, 2014.  REUTERS/U.S. Geological Survey/Handout  (UNITED STATES - Tags: ENVIRONMENT DISASTER) THIS IMAGE HAS BEEN SUPPLIED BY A THIRD PARTY. IT IS DISTRIBUTED, EXACTLY AS RECEIVED BY REUTERS, AS A SERVICE TO CLIENTS. FOR EDITORIAL USE ONLY. NOT FOR SALE FOR MARKETING OR ADVERTISING CAMPAIGNS

Stone-wool is formed in igneous rock and can be used as eco-friendly insulation. Image: REUTERS/U.S. Geological Survey/Handout

Kristin Hunt
Our Impact
What's the World Economic Forum doing to accelerate action on Nature and Biodiversity?
The Big Picture
Explore and monitor how Future of the Environment is affecting economies, industries and global issues
A hand holding a looking glass by a lake
Crowdsource Innovation
Get involved with our crowdsourced digital platform to deliver impact at scale
Stay up to date:

Future of the Environment

You're probably familiar with fiberglass insulation, the bright pink material that lines the walls of so many homes. But what about stone wool insulation?

While fiberglass insulation is made with recycled glass, stone wool (also called rock wool or mineral wool) is even more sustainable. It comes from natural igneous rock — the kind that forms after lava cools — and a steelmaking byproduct called slag. These substances are melted and spun into fibers to create the insulation. Over the past few years, stone wool has gained traction with eco-conscious architects and designers.

Eco-friendly insulation Image: Green Matters

"I encourage or really demand that all my contractors use non-toxic, formaldehyde-free insulation," says Tracey Stephens, who runs the eco-smart firm Tracey Stephens Interior Design. "The one we’re using now that we’re really excited about is called Rockwool."

Rockwool, formerly known as Roxul, is one of the biggest stone wool companies on the market. But regardless of brand name, stone wool comes with some incredible features. It naturally muffles sound, and repels both fire and water.

"I was at a trade show last month and one of the displays was a piece of this installation with a flame under it, constantly burning," says Stephens. "Nothing happening. Another one had water dripping on it, and nothing happening. Then they had this hallway constructed where you walk in from the very loud convention floor and through this little hall that has the insulation in it and it was dead quiet. It was amazing."

What makes stone wool more sustainable than fiberglass? Well, for one, it contains more recycled material. According to the U.S. Department of Energy, fiberglass insulation typically contains 40-60 percent recycled content, while stone wool averages 75 percent.

Stone wool is also more energy efficient. Compared to fiberglass, it boasts a higher R-value. This number is used to measure how well a material resists thermal energy transfer — basically, how well it insulates. Good insulation slows heat from leaving your home in the winter, and entering your home in the summer. So it's a big factor in your overall energy use. Stone wool has an R-value of 3-3.3 per inch, edging out fiberglass's R-value of 2.2-2.7 per inch.

Stone wool has faced controversy over its formula, as manufacturers traditionally used a formaldehyde binder to create it. But that practice is on its way out. Major companies have rolled out formaldehyde-free options in the past year, making stone wool an even safer option for your home.

Have you read?

You can find stone wool insulation in home improvement stores, or talk to your contractor about using it. How It's Made has more information on the manufacturing process:

And if you'd like to explore your insulation options even further, be sure to check out the current innovations in chicken feathers.

Don't miss any update on this topic

Create a free account and access your personalized content collection with our latest publications and analyses.

Sign up for free

License and Republishing

World Economic Forum articles may be republished in accordance with the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International Public License, and in accordance with our Terms of Use.

The views expressed in this article are those of the author alone and not the World Economic Forum.

Related topics:
Nature and BiodiversityEnergy TransitionManufacturing and Value Chains
World Economic Forum logo
Global Agenda

The Agenda Weekly

A weekly update of the most important issues driving the global agenda

Subscribe today

You can unsubscribe at any time using the link in our emails. For more details, review our privacy policy.

World breaches critical 1.5°C warming threshold 12 months in a row, and other nature and climate stories you need to read this week

Tom Crowfoot

July 17, 2024

About Us



Partners & Members

  • Sign in
  • Join Us

Language Editions

Privacy Policy & Terms of Service

© 2024 World Economic Forum