Improvements in cavity wall insulation: Recticel’s Eurowall +

As thermal requirements for new builds have increased, designers have little option but to increase quantities of insulation within the external envelope of a structure such as the walls, floors and roof.

As cavities in masonry construction get bigger to achieve compliance, so do the structural requirements. A 100mm wide cavity is currently the norm.

If the cavity is fully filled with insulation then care needs to be taken to ensure driving rain can’t get into the cavity and bridge across. A fully filled cavity is not recommended in some parts of the country due to the severity of driving rain, so this leaves little option other than a wider partially filled cavity or internal or external insulation.

All of these options either reduce the internal floor area or increase the external footprint. The net result is less houses per plot or smaller rooms to live in.

Introducing Eurowall +

In the second of two articles examining the development of commonly used cavity insulation materials (also see Alternatives to glass wool: Solutions for smaller wall cavities) we look at Eurowall + manufactured by Recticel. It’s a foil-faced rigid PIR (polyisocyanurate) board that’s 90mm thick which gives a partially filled cavity. This means that houses can continue to be built within the normal build limits and sizes.

The quality and accuracy of the brickwork and blockwork are vital to ensure that there’s a 10mm clear space in the 100mm cavity. The boards should never be pushed into a cavity, the inner leaf should always be constructed ahead of the outer leaf so that mortar can be cleaned off the back of the inner leaf before installing.

Building control surveyors and our business partners - LABC Warranty will also check this as work proceeds to ensure mortar snots, spacer placement and inaccurate bricklaying don’t bridge the remaining cavity ensuring that the wall performs as it’s designed to.  

With care and skill a high performance solution can be achieved that keeps the householder warm and cosy and reduces energy costs.

Further information

Eurowall + Registered Details certificate

Eurowall + on the Rectical website

Part L Approved Document: Conservation of fuel and power

Please Note: Every care was taken to ensure the information was correct at the time of publication. Any written guidance provided does not replace the user’s professional judgement. It is the responsibility of the dutyholder or person carrying out the work to ensure compliance with relevant building regulations or applicable technical standards.