Insulation·rigid polyurethane 50mm
rigid polyurethane · 50mm
R 2.17
U 0.427 W/m²·K

rigid polyurethane, 50 mm — R 2.17

50 mm divided by a conductivity of 0.023 gives an R-value of 2.17. The U-value is 0.427, so a square metre leaks 8.53 W across a 20-degree difference.

Standards it meets

Not up to any of them yet

Material
rigid polyurethane
Thickness
50 mm
Thermal conductivity
0.023 W/m·K
Thermal resistance
2.17 m²·K/W
U-value
0.427 W/m²·K
Heat lost per square metre
8.53 W
As concrete
3.48 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 panel15 mm
  • phenolic foam43 mm
  • extruded polystyrene61 mm
  • graphite EPS67 mm
  • white EPS78 mm
  • glass wool80 mm
  • mineral wool87 mm
  • cellulose91 mm
  • timber283 mm
  • plasterboard391 mm
  • concrete3478 mm

Nearby cells

rigid polyurethane 30mm
R 1.3
rigid polyurethane 70mm
R 3.04
phenolic foam 50mm
R 2.5
extruded polystyrene 50mm
R 1.79

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 50mm
R 7.14
phenolic foam 50mm
R 2.5
rigid polyurethane 50mm
R 2.17
extruded polystyrene 50mm
R 1.79
graphite EPS 50mm
R 1.61
white EPS 50mm
R 1.39
glass wool 50mm
R 1.35
mineral wool 50mm
R 1.25
cellulose 50mm
R 1.19
timber 50mm
R 0.38
plasterboard 50mm
R 0.28
concrete 50mm
R 0.03

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 50 mm of rigid polyurethane?

2.17 — 50 mm in metres divided by a conductivity of 0.023.

Q. And the U-value?

0.427. That is 2.34 — the resistance plus 0.17 of surface — turned upside down, and a square metre leaks 8.53 W across 20 degrees.

Q. How much concrete would match it?

3.48 metres.

Q. Which standards does it meet?

At 0.427 it does not clear any of them yet.