mineral wool · 150mm
R 3.75
U 0.255 W/m²·K
mineral wool, 150 mm — R 3.75
150 mm divided by a conductivity of 0.04 gives an R-value of 3.75. The U-value is 0.255, so a square metre leaks 5.1 W across a 20-degree difference.
Standards it meets
- loose standard 0.30
- Material
- mineral wool
- Thickness
- 150 mm
- Thermal conductivity
- 0.04 W/m·K
- Thermal resistance
- 3.75 m²·K/W
- U-value
- 0.255 W/m²·K
- Heat lost per square metre
- 5.1 W
- As concrete
- 6 m
Thickness for the same performance
This is the number that shows what insulation is worth. Matching 100 mm of XPS with concrete alone would take 5.7 metres of it. No one builds a wall like that — which is why a concrete building only gets warm once a thin layer of insulation is added.
- vacuum panel26 mm
- phenolic foam75 mm
- rigid polyurethane86 mm
- extruded polystyrene105 mm
- graphite EPS116 mm
- white EPS135 mm
- glass wool139 mm
- cellulose158 mm
- timber488 mm
- plasterboard675 mm
- concrete6000 mm
Nearby cells
Same material, other thicknesses
Same thickness, other materials
How to read this
- Thermal resistance is the thickness in metres divided by the conductivity. Bigger is better.
- The U-value adds 0.17 of surface resistance and then flips the total. Smaller is better.
- Resistances add across layers, so a whole wall is the sum of its parts.
- Conductivity varies by product; the values here are typical for the material.
Frequently asked questions
Q. What is the R-value of 150 mm of mineral wool?
3.75 — 150 mm in metres divided by a conductivity of 0.04.
Q. And the U-value?
0.255. That is 3.92 — the resistance plus 0.17 of surface — turned upside down, and a square metre leaks 5.1 W across 20 degrees.
Q. How much concrete would match it?
6 metres.
Q. Which standards does it meet?
At 0.255 it clears 1 of them.