Ca-Mg-Al silicates / soda-lime glass fibres
ChemistryMineral wool is specified as Ca-Mg-Al silicates / soda-lime glass fibres. Density band 20–150 kg/m³ products.
Darker cells mean a higher score for this topic on that metric.
Strength16
Heat resistance86
Fire performance96
Insulation86
Workability70
Circularity58
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Last reviewed Sources & creditsMedia creditsMethodology
Quick answers
Is Mineral wool non-combustible?
Declared reaction class in this atlas: A1. Assemblies still need resistance tests.
Does Mineral wool insulate?
Thermal mark 86/100 versus the atlas. Conductivity note: λ ~0.032–0.040 W/m·K typical batts.
What is the density band?
20–150 kg/m³ products
How is it made?
Origin story: Slag wool 19th c.; glass wool 1930s (US / Germany / Denmark).
Can it be recycled?
Circularity mark 58/100 — editorial, route-specific.
Typical melting or failure heat?
softens ~1000 °C class (stone)
heat 86 · fire 96
What holds Mineral wool together is not the nickname. Formula Ca-Mg-Al silicates / soda-lime glass fibres, density 20–150 kg/m³ products.
Meters are atlas-relative. Grades are the SKUs buyers write.
Phases
Microstructure
OrderProcessing sets grain, crystallinity or fibre orientation — the reason two lots of Mineral wool can test differently.
Interfaces
SurfacesCoatings, oxide films, sizings or paper faces often decide weather and fire behaviour more than the bulk brochure.
Defects
FlawsInclusions, voids, knots, pinholes or residual stress start the failures that mill certificates do not list.
Grades
VariantsMineral wool is a family. Grade names below are the ones buyers actually write on RFQs.
Ageing
TimeMoisture, UV, creep, hydrogen or carbonation shift properties in service. Design to the aged state.
Relative meters
Strength16
Strength is an editorial 0–100 mark relative to the other 31 materials in this atlas — not a laboratory certificate.
Heat envelope86
Heat envelope is an editorial 0–100 mark relative to the other 31 materials in this atlas — not a laboratory certificate.
Fire behaviour96
Fire behaviour is an editorial 0–100 mark relative to the other 31 materials in this atlas — not a laboratory certificate.
Insulation86
Insulation is an editorial 0–100 mark relative to the other 31 materials in this atlas — not a laboratory certificate.
Workability70
Workability is an editorial 0–100 mark relative to the other 31 materials in this atlas — not a laboratory certificate.
Circularity58
Circularity is an editorial 0–100 mark relative to the other 31 materials in this atlas — not a laboratory certificate.
Grades
Glass wool batt
Housing cavities.Housing cavities.
Stone wool board
Façades, fire stops.Façades, fire stops.
High-T industrial
Pipe and oven.Pipe and oven.
Blowing wool
Attics.Attics.
Wired mattress
Marine / HVAC.Marine / HVAC.
Bonds
Primary bonding
Mineral wool holds together by ionic/covalent networks.
Secondary forces
Hydrogen bonds, van der Waals stacks or grain-boundary cohesion set toughness and moisture uptake.
Composites & fills
Fillers, fibres, plasticisers or aggregates are part of the real product, not impurities.
Environment film
Oxides, chars, sizings or paints are the layer the world actually meets.
Change the grade, the coating or the moisture and you have a different material with the same English name.
Keep exploring
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The low-λ organic foam of fridges and buildings — excellent insulation, a fire design problem unless PIR and coverings are honest.
Overall 46 📦Vacuum insulated panel
A sealed vacuum sandwich — λ around 0.004–0.008 W/m·K until the envelope leaks.
Overall 44 🕯️Phase-change material
Latent-heat packets that flatten temperature swings — not a substitute for λ insulation, a complement.
Overall 36