Mineral Wool V PIR in Cavity Walls

Installation, cost, condensation and much more needs to be considered when it comes to specifying the insulation within your cavity wall construction, but how do they compare thermally?

Is the additional cost for the PIR worth it when it comes to thermal performance, overall heating demand and carbon emissions for Building Regulations.

We have run comparable u-value calculations to see the difference in the average W/m2k between a wall constructed with mineral wool and similarly PIR.

Cavity Wall Construction with 100mm Mineral Wool Insulation

0.28 W/m2k

Cavity Wall Construction with 90mm PIR Insulation

0.20 W/m2k

(Based on thermal conductivity values of 0.032 for mineral wool compared to 0.02 for PIR)

The selection of insulation for your project has to be considered from all angles and for different scenarios, each of these products will be more adequately suited. However, If you are looking to improve your thermal performance to reduce C02 emissions, meet Building regulations etc, the installation of PIR cavity insulation could be a great place to start.