Knauf Dritherm 32 Insulation

Knauf Insulation Earthwool DriTherm® Cavity Slab 32 is the superior solution for external full-fill masonry cavity walls. Its water-repellent, non-combustible design combined with best possible Euroclass A1 reaction to fire classification ensures top thermal performance and peace of mind in your construction projects.

Plus, Dritherm is made from ecofriendly ECOSE® Technology that uses a unique bio-based binder formula so you can build better while protecting the planet!

Knauf Dritherm 32 vs 37

Knauf Dritherm 32 has a lower thermal conductivity so makes a more effective insulation per millimetre of material thickness.

What is thermal conductivity?

Also called the lambda (λ) value or k value, thermal conductivity is the number of Watts conducted per metre thickness of the material per degree of temperature difference between one side and the other - W/mK.

For insulation the lower the thermal conductivity the better, because the material conducts less heat energy.

Thermal Conductivity

Knauf Dritherm 32 = 0.032 W/mK

Knauf Dritherm 37= 0.037 W/mK

Dritherm 32 has a lower thermal conductivity making it a better insulator. Thermal conductivity is a property of the material and does not take into account thickness. Two different thicknesses of the same material still have the same λ-value.

What is thermal resistance?

To compare the relative performance of different thicknesses of materials means working out their thermal resistance (units: m²K/W). Thermal resistance is calculated by dividing the thickness of the material by its thermal conductivity, giving an R-value specific to that thickness.

So the R-value gives the overall insulation performance, taking into account the thermal conductivity and the thickness of the materials.