phenolic foam · 30mm
R 1.5
U 0.599 W/m²·K
phenolic foam, 30 mm — R 1.5
30 mm divided by a conductivity of 0.02 gives an R-value of 1.5. The U-value is 0.599, so a square metre leaks 11.98 W across a 20-degree difference.
Standards it meets
Not up to any of them yet
- Material
- phenolic foam
- Thickness
- 30 mm
- Thermal conductivity
- 0.02 W/m·K
- Thermal resistance
- 1.5 m²·K/W
- U-value
- 0.599 W/m²·K
- Heat lost per square metre
- 11.98 W
- As concrete
- 2.4 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 panel11 mm
- rigid polyurethane35 mm
- extruded polystyrene42 mm
- graphite EPS47 mm
- white EPS54 mm
- glass wool55 mm
- mineral wool60 mm
- cellulose63 mm
- timber195 mm
- plasterboard270 mm
- concrete2400 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 30 mm of phenolic foam?
1.5 — 30 mm in metres divided by a conductivity of 0.02.
Q. And the U-value?
0.599. That is 1.67 — the resistance plus 0.17 of surface — turned upside down, and a square metre leaks 11.98 W across 20 degrees.
Q. How much concrete would match it?
2.4 metres.
Q. Which standards does it meet?
At 0.599 it does not clear any of them yet.