Insulation·rigid polyurethane 100mm
rigid polyurethane · 100mm
R 4.35
U 0.221 W/m²·K

rigid polyurethane, 100 mm — R 4.35

100 mm divided by a conductivity of 0.023 gives an R-value of 4.35. The U-value is 0.221, so a square metre leaks 4.43 W across a 20-degree difference.

Standards it meets

  • loose standard 0.30
Material
rigid polyurethane
Thickness
100 mm
Thermal conductivity
0.023 W/m·K
Thermal resistance
4.35 m²·K/W
U-value
0.221 W/m²·K
Heat lost per square metre
4.43 W
As concrete
6.96 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 panel30 mm
  • phenolic foam87 mm
  • extruded polystyrene122 mm
  • graphite EPS135 mm
  • white EPS157 mm
  • glass wool161 mm
  • mineral wool174 mm
  • cellulose183 mm
  • timber565 mm
  • plasterboard783 mm
  • concrete6957 mm

Nearby cells

rigid polyurethane 70mm
R 3.04
rigid polyurethane 120mm
R 5.22
phenolic foam 100mm
R 5
extruded polystyrene 100mm
R 3.57

Same material, other thicknesses

rigid polyurethane 10mm
R 0.43
rigid polyurethane 20mm
R 0.87
rigid polyurethane 30mm
R 1.3
rigid polyurethane 50mm
R 2.17
rigid polyurethane 70mm
R 3.04
rigid polyurethane 100mm
R 4.35
rigid polyurethane 120mm
R 5.22
rigid polyurethane 150mm
R 6.52
rigid polyurethane 200mm
R 8.7
rigid polyurethane 250mm
R 10.87
rigid polyurethane 300mm
R 13.04
rigid polyurethane 400mm
R 17.39

Same thickness, other materials

vacuum panel 100mm
R 14.29
phenolic foam 100mm
R 5
rigid polyurethane 100mm
R 4.35
extruded polystyrene 100mm
R 3.57
graphite EPS 100mm
R 3.23
white EPS 100mm
R 2.78
glass wool 100mm
R 2.7
mineral wool 100mm
R 2.5
cellulose 100mm
R 2.38
timber 100mm
R 0.77
plasterboard 100mm
R 0.56
concrete 100mm
R 0.06

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 100 mm of rigid polyurethane?

4.35 — 100 mm in metres divided by a conductivity of 0.023.

Q. And the U-value?

0.221. That is 4.52 — the resistance plus 0.17 of surface — turned upside down, and a square metre leaks 4.43 W across 20 degrees.

Q. How much concrete would match it?

6.96 metres.

Q. Which standards does it meet?

At 0.221 it clears 1 of them.