Compare mineral wool and EPS within a specific assembly. A material name does not automatically establish fire suitability, moisture performance or façade durability.
Same function, different products
Define the application first: façades, roofs and floors face different conditions. Compare products declared suitable for that use.
Thermal outcome
Use verified design conductivity and actual thickness. Options targeting the same U-value may need different geometry and fixings.
Moisture and air
Obtain vapour properties from documentation and design rain control and airtightness separately. Breathability is not a complete comparison.
Fire and mechanical conditions
Assess the complete system, substrate and fixings. Do not transfer an individual material classification to the whole façade without evidence.
Common mistakes and life cycle
Comparing price per cubic metre without installation and finishes is misleading. Include waste, details, repair access and verified component compatibility.
| Item | Parameter | Check / result |
|---|---|---|
| Thermal | Same target U | Complete assembly |
| Safety | System requirements | Evidence |
| Cost | Installation and upkeep | Life cycle |
What this means for your project
Complete a matrix for two specific systems. Keep unverified properties marked unknown rather than assuming an advantage.
Sources and scope of review
- ISO 6946:2017 — Thermal resistance and transmittance
- PNNL / Building America — Moisture control for residential buildings
Related reading
- R-Value and U-Value: How to Read Thermal Performance
- How to Choose an External Wall Assembly
- ZeroHouse Lab: Comparing Four External Wall Concepts