Insulation·timber 30mm
timber · 30mm
R 0.23
U 2.495 W/m²·K

timber, 30 mm — R 0.23

30 mm divided by a conductivity of 0.13 gives an R-value of 0.23. The U-value is 2.495, so a square metre leaks 49.9 W across a 20-degree difference.

Standards it meets

Not up to any of them yet

Material
timber
Thickness
30 mm
Thermal conductivity
0.13 W/m·K
Thermal resistance
0.23 m²·K/W
U-value
2.495 W/m²·K
Heat lost per square metre
49.9 W
As concrete
0.37 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 polyurethane5 mm
  • extruded polystyrene6 mm
  • graphite EPS7 mm
  • white EPS8 mm
  • glass wool9 mm
  • mineral wool9 mm
  • cellulose10 mm
  • plasterboard42 mm
  • concrete369 mm

Nearby cells

timber 20mm
R 0.15
timber 50mm
R 0.38
cellulose 30mm
R 0.71
plasterboard 30mm
R 0.17

Same material, other thicknesses

timber 10mm
R 0.08
timber 20mm
R 0.15
timber 30mm
R 0.23
timber 50mm
R 0.38
timber 70mm
R 0.54
timber 100mm
R 0.77
timber 120mm
R 0.92
timber 150mm
R 1.15
timber 200mm
R 1.54
timber 250mm
R 1.92
timber 300mm
R 2.31
timber 400mm
R 3.08

Same thickness, other materials

vacuum panel 30mm
R 4.29
phenolic foam 30mm
R 1.5
rigid polyurethane 30mm
R 1.3
extruded polystyrene 30mm
R 1.07
graphite EPS 30mm
R 0.97
white EPS 30mm
R 0.83
glass wool 30mm
R 0.81
mineral wool 30mm
R 0.75
cellulose 30mm
R 0.71
timber 30mm
R 0.23
plasterboard 30mm
R 0.17
concrete 30mm
R 0.02

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 30 mm of timber?

0.23 — 30 mm in metres divided by a conductivity of 0.13.

Q. And the U-value?

2.495. That is 0.4 — the resistance plus 0.17 of surface — turned upside down, and a square metre leaks 49.9 W across 20 degrees.

Q. How much concrete would match it?

0.37 metres.

Q. Which standards does it meet?

At 2.495 it does not clear any of them yet.