cellulose · 70mm
R 1.67
U 0.544 W/m²·K
cellulose, 70 mm — R 1.67
70 mm divided by a conductivity of 0.042 gives an R-value of 1.67. The U-value is 0.544, so a square metre leaks 10.89 W across a 20-degree difference.
Standards it meets
Not up to any of them yet
- Material
- cellulose
- Thickness
- 70 mm
- Thermal conductivity
- 0.042 W/m·K
- Thermal resistance
- 1.67 m²·K/W
- U-value
- 0.544 W/m²·K
- Heat lost per square metre
- 10.89 W
- As concrete
- 2.67 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 panel12 mm
- phenolic foam33 mm
- rigid polyurethane38 mm
- extruded polystyrene47 mm
- graphite EPS52 mm
- white EPS60 mm
- glass wool62 mm
- mineral wool67 mm
- timber217 mm
- plasterboard300 mm
- concrete2667 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 70 mm of cellulose?
1.67 — 70 mm in metres divided by a conductivity of 0.042.
Q. And the U-value?
0.544. That is 1.84 — the resistance plus 0.17 of surface — turned upside down, and a square metre leaks 10.89 W across 20 degrees.
Q. How much concrete would match it?
2.67 metres.
Q. Which standards does it meet?
At 0.544 it does not clear any of them yet.