Insulation·glass wool 10mm
glass wool · 10mm
R 0.27
U 2.271 W/m²·K

glass wool, 10 mm — R 0.27

10 mm divided by a conductivity of 0.037 gives an R-value of 0.27. The U-value is 2.271, so a square metre leaks 45.43 W across a 20-degree difference.

Standards it meets

Not up to any of them yet

Material
glass wool
Thickness
10 mm
Thermal conductivity
0.037 W/m·K
Thermal resistance
0.27 m²·K/W
U-value
2.271 W/m²·K
Heat lost per square metre
45.43 W
As concrete
0.43 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 panel2 mm
  • phenolic foam5 mm
  • rigid polyurethane6 mm
  • extruded polystyrene8 mm
  • graphite EPS8 mm
  • white EPS10 mm
  • mineral wool11 mm
  • cellulose11 mm
  • timber35 mm
  • plasterboard49 mm
  • concrete432 mm

Nearby cells

glass wool 20mm
R 0.54
white EPS 10mm
R 0.28
mineral wool 10mm
R 0.25

Same material, other thicknesses

glass wool 10mm
R 0.27
glass wool 20mm
R 0.54
glass wool 30mm
R 0.81
glass wool 50mm
R 1.35
glass wool 70mm
R 1.89
glass wool 100mm
R 2.7
glass wool 120mm
R 3.24
glass wool 150mm
R 4.05
glass wool 200mm
R 5.41
glass wool 250mm
R 6.76
glass wool 300mm
R 8.11
glass wool 400mm
R 10.81

Same thickness, other materials

vacuum panel 10mm
R 1.43
phenolic foam 10mm
R 0.5
rigid polyurethane 10mm
R 0.43
extruded polystyrene 10mm
R 0.36
graphite EPS 10mm
R 0.32
white EPS 10mm
R 0.28
glass wool 10mm
R 0.27
mineral wool 10mm
R 0.25
cellulose 10mm
R 0.24
timber 10mm
R 0.08
plasterboard 10mm
R 0.06
concrete 10mm
R 0.01

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 10 mm of glass wool?

0.27 — 10 mm in metres divided by a conductivity of 0.037.

Q. And the U-value?

2.271. That is 0.44 — the resistance plus 0.17 of surface — turned upside down, and a square metre leaks 45.43 W across 20 degrees.

Q. How much concrete would match it?

0.43 metres.

Q. Which standards does it meet?

At 2.271 it does not clear any of them yet.