Soprema - IWI Post - Unity Lime

How to avoid unintended consequences of specifying the wrong internal wall insulation (IWI)

There are around 28 million homes in the UK which are deemed to be some of the oldest housing constructions in Europe, according to the Alliance for Sustainable Building Products (ASBP). Data from the non-profit organisation also suggests 32 per cent of buildings in the UK were constructed before 1919, meaning they are predominantly solid wall structures

IWI – the Benefits

IWI provides improved energy efficiency of buildings and is often the default choice due to its simplicity. It is particularly effective in solid wall construction, where external wall insulation (EWI) is not an option due to extenuating factors.

Yet, there can be the unintended consequences if the wrong type of IWI material is specified and installed. For this reason, wood fibre is an ideal choice for IWI as it is breathable and allows moisture to flow through, reducing the risk of mould and moisture-related problems. This is especially important in social housing where old, solid wall homes are common.

Breathable Wall Insulation

Breathable internal wall insulation, such as wood fibre, is a preferred option over other materials, such as XPS or PIR. This is because it allows for the safe passage of moisture through the walls, preventing the accumulation of harmful water which can lead to high humidity levels and damage to the building structure. Breathable insulation also helps regulate humidity levels within a building, promoting healthy indoor air quality and reducing the risk of respiratory and other health issues associated with too high or too low humidity levels.

Savvy Specification

Soprema UK offers a natural wood fibre insulation solution for internal walls: PAVATEX. The sustainable wood fibre boards are made from waste wood that is collected from various sawmills, heated and then pressurised. PAVATEX has excellent heat storage capacity, offering excellent thermal insulation properties as well as keeping rooms cool in summer.Just like all of our wood fibre insulation products, PAVATEX is characterised by superior breathability, allowing moisture to move within a wall or roofing system, and regulating it at safe levels to prevent it from entering the building fabric.

PAVATEX consists of both new build and retrofit systems for walls, floors and roofs. Its advantages are crucial for the environment, building owners and contractors alike.

Author: www.architectsdatafile.co.uk in association with Soprema UK

Date March 2023