Choosing EPS for Cavity Wall Insulation Applications

If you’re thinking of installing insulation in a new build, or retrofitting an existing building, you may have been looking for alternative materials for cavity wall insulation applications. As you’ve probably seen our post or video on floor insulation applications, we wanted to take a moment to explain why Expanded Polystyrene is a viable alternative to other materials on the market for both new build and retrofit cavity wall applications. In this post, we’ll take a look at using EPS as an alternative to PIR for wall insulation applications, and explore a variety of U-values and the thicknesses required to achieve them.

How is EPS used in cavity wall insulation applications?

KORE offers a few different solutions to insulate cavity walls, including KORE Fill Original Bonded Bead (0.035W/mK), and high performing KORE Fill Diamond Bonded Bead (0.033W/mK). KORE Fill is suitable for use in new build and retrofit applications where a cavity width of at least 40mm (50mm for Diamond bead) exists.

In new build applications, the lowest achievable U-value is only limited by the width of the cavity. With EPS, U-values as low as 0.12W/m2K are achievable with the right planning, design and installation.

KORE Fill Cavity Wall Insulation is installed by our network of NSAI, SEAI and KORE Approved Contractors located across the country. The product can be installed from outside the home and causes minimal disruption for occupants (in retrofit applications), and minimises disruption on the job-site in new build applications. In addition, the product can be installed quickly and easily and will last the entire lifetime of the building. Learn more about the installation process for cavity wall insulation.

What U-values can be achieved with EPS cavity wall insulation?

KORE’s cavity wall insulation solutions can easily meet and exceed Ireland’s Building Regulations when it comes to insulating external walls. The tables below show the thickness of cavity wall insulation required, and the equivalent in PIR. Note that a vapour control layer is required on the inside face of the internal leaf when installing EPS.

To Achieve a U-Value of 0.21W/m2K

The minimum U-value required to meet Ireland’s Building Regulations is 0.21W/m2K. This can be achieved with the following:

 

Material Thermal Conductivity Thickness Required U-Value Achieved
PIR Insulation (Rigid Board) 0.021W/mK 100mm PIR 0.21W/m2K
Amount of EPS Required to Achieve the Same U-Value
KORE Fill Original (Bonded Bead) 0.035W/mK 150mm KORE Fill Original 0.21W/m2K
-OR-
KORE Fill Diamond + KORE Thermal Board EPS70 Silver 0.033W/mk & 0.031W/mK 100mm KORE Fill Diamond + 35mm KORE Thermal Board 0.21W/m2K

 

To Achieve a U-Value of 0.18W/m2K

 

Material Thermal Conductivity Thickness Required U-Value Achieved
PIR Insulation (Rigid Board) 0.021W/mK 110mm PIR 0.18W/m2K
Amount of EPS Required to Achieve the Same U-Value
KORE Fill Diamond 0.033W/mK 170mm KORE Fill Diamond 0.18W/m2K
-OR-
KORE Fill Diamond + KORE Thermal Board EPS70 Silver 0.033W/mK & 0.031W/mK 150mm KORE Fill Diamond + 15mm KORE Thermal Board 0.18W/m2K

 

To Achieve a U-value of 0.15W/m2K

 

Material Thermal Conductivity Thickness Required U-Value Achieved
PIR Insulation (Rigid Board) 0.021W/mK 135mm PIR 0.15W/m2K
Amount of EPS Required to Achieve the Same U-Value
KORE Fill Diamond 0.033W/mK 200mm KORE Fill Diamond 0.15W/m2K
-OR-
KORE Fill Diamond + KORE Thermal Board EPS70 Silver 0.033W/mK & 0.031W/mK 150mm KORE Fill Diamond + 45mm KORE Thermal Board 0.15W/m2K

 

published:08 Aug 2018
,

Join KORE at our next CPD roadshow event in Wexford on 25th September. Free tickets are available by clicking on the image above. Seating is limited so register quickly.