Insulation: MATERIALS ENCYcLOPEDIA
Applications for this system
Wall and roof insulation (batt)
Loose-fill insulation (blown applications)
Wall cladding (board)
Roof and sub-slab insulation (rigid board)
Most mineral wools are made from mining tailings or slag, though almost any stone can be used
Binders (vary by manufacturer)
Oils for dust suppression (varies by manufacturer)
Ratings Chart for mineral wool insulation
The ratings chart shows comparative performance in each criteria category. Click on the tabs below for detailed analysis of each criteria.
- HOW THE SYSTEM WORKS
- ENVIRONMENTAL IMPACTS
- EMBODIED CARBON
- ENERGY EFFICIENCY
- MATERIAL COSTS
- LABOUR INPUT
- SKILL LEVEL REQUIRED
- SOURCING & AVAILABILITY
- CODE COMPLIANCE
- INDOOR AIR QUALITY
- FUTURE DEVELOPMENT
Mineral wool System
Molten rock is spun (using a process similar to making cotton candy) and the resulting fine fibers are intertwined and layered and held together using a binder. Mineral wool can be formed at a variety of densities for different insulation uses.
Environmental Impact Rating
Harvesting — Moderate
The mining of ore is a high-impact process, but as a recycled product the impacts are mitigated.
Manufacturing — High
To make mineral wool, rock must be heated to approximately 1600 °C (2900∞F), an energy intensive process with high fuel usage and emissions. The chemical binders used to form the insulation into batts and boards have wide-ranging impacts throughout their life cycle.
Transportation — Low to High
Sample building uses 930 kg of mineral wool:
1.4 MJ per km by 15 ton truck
0.9 MJ per km by 35 ton truck
North American production is limitedregional. Impacts accrue proportional to distance traveled, though the material is lightweight.
Installation — Moderate
Products carry carcinogen warnings on the label, and dust and offcuts can proliferate in the environment.
Recyclable – Plastic packaging.
Landfill – Insulation offcuts.
Chart of Embodied energy & carbon
R-value: 3.7–4.5 per inch
A wide variety of mineral wool products are available at different densities and thicknesses, and thermal properties vary with density.
All mineral wool insulation requires an air control layer on both sides of the insulation. Gaps and voids in the insulation due to improper installation will lower the thermal performance.
Material costs: moderate
Market penetration of mineral wool batts has increased dramatically over the past decade, and costs are often competitive with mainstream insulation choices like fiberglass.
Labour Input: low to moderate
The installation of mineral wool products is similar to that of any batt or board style of insulation.
Mineral wool fibers and formaldehyde binders are both considered carcinogenic. Material will cause skin irritation.
Skill level required for homeowners: Low
Batt and board insulation can be successfully installed with very little experience, as long as care is taken to ensure tight fits in all cavities and to avoid voids or gaps.
Sourcing & availability: Easy
Mineral wool products can be sourced through many building supply stores, though availability will vary by region.
Mineral wool is not affected by moisture and offers no food value to insects and rodents. It can be expected to have a long lifespan.
Mineral wool products are produced to meet all building code standards.
Indoor air quality: low to moderate
During installation, mineral wool particulate is dangerous. To the degree that particulate is sealed in the wall, there should be little evidence of it in the air of the finished home. Many mineral wool products use formaldehyde binders, which off-gas throughout their lifespan.
Resources for further research
Mineral wool products have been in use for many decades. Future developments are likely to include the use of non-off-gassing binders.
Tips for successful mineral wool insulation
Batt and rigid board installations must be free of voids and gaps to achieve maximum thermal performance. Manufacturers will provide specifications for installation.