Energy Efficiency and Historic Buildings: What is the wall moisture response to floor retrofit solutions?

Energy efficient building design and modification plays an important role in reducing the UK’s carbon footprint. However, it can be particularly difficult to make informed decisions when modifying and conserving historic buildings. The replacement of solid ground floors can be used to improve the energy efficiency of historic buildings, however this can sometimes have a detrimental impact on the building fabric and the indoor environment. It is a widely-held belief that if an impermeable ground bearing slab is installed in an old building, ground moisture will be ‘driven’ up adjacent walls.  Although there are numerous references to this phenomenon, both in technical and product literature, they tend to be anecdotal and unsupported by scientific evidence.   

This PhD will use field monitoring to measure seasonal changes in soil moisture, wall moisture and indoor humidity in historic buildings across the City of Bath and south west England. This will be supported by laboratory experiments using our state-of-the-art facilities to measure water vapour transfer through typical floor and wall materials. The investigation is supported by Historic England, the public body that looks after England’s historic environment. The findings of the research will enable informed decisions to be made about floor retrofit solutions and wall damp within historic buildings.