Insulating Solid Walls – Old and Historic Buildings

What Does Breathability Mean when Insulating Old and Historic Buildings? The breathability of a building relates to the passage of water through its building structure and has nothing to do with air movement! It is concerned with how building materials can absorb and release water both as a vapour and as a liquid. Older buildings (generally built pre-1919) were constructed so that water could pass through the complete structure, so when insulating or renovating an old or historic building, it is critical to take this into account. This will ensure that this breathable capability will not be blocked which could cause the structure to decay or could adversely affect the interior air quality. Older buildings do not have a cavity and so the water vapour has nowhere to escape to except to the outside or inside of the structure where it will evaporate when favourable conditions prevail. It is estimated that about 25% of the UK’s building stock have solid walls.