Gwynne Anthony 2020

ART506 Dissertation 2019. Anthony Gwynne . 21 Figure 4: Typical section through a traditional 'breathing' building (Not to scale) (Source: Gwynne, 2013). 3.2.4 Inappropriate repair and renovation of traditional buildings When traditional buildings are maintained and upgraded with inappropriate modern hard non- permeable materials for example cement based products or plastic membranes and finishes, they can trap moisture and potentially lead to the deterioration of the building fabric and finishes. Additional problems can occur with condensation and mould growth caused by high levels of water vapour produced by the occupants and lack of natural ventilation caused by sealing up of gaps and blocking up of open flues and chimneys (Figure 5) . Traditional roof coverings typically constructed using stone, clay tiles, slate, timber shingle or thatch are fixed to roof structure, interlaced together over large areas allowing for movement and air to circulate. The roof coverings deflect most rain, any moisture absorbed is evapourated away from the building by natural air circulation Roof overhang and rain water gutters and down pipes dispose of water away from the building Solid walls typically constructed using naturally permeable materials (stone or brick and lime mortar, cob walling or wattle and daub) Natural lime render & lime wash finishes that allows moisture to evaporate. Ground floors typically constructed using permeable materials (earth/ lime/ash/ natural flag stones) Rain/penetrating damp Natural lime plaster & lime wash finishes Walls breathe naturally and any moisture is allowed to evaporate Floors breathe naturally and any moisture is allowed to evaporate Lath & plaster with limewash finishes Roof breathes naturally and any moisture is allowed to evaporate Gravel paths absorbs rain Rising damp Rising damp Walls breathe naturally and moisture is allowed to evaporate Well maintained land drain/ rain water disposal pipes and adequate soakaways takes water away from the building Roof breathes naturally and any moisture is allowed to evaporate Passive stack ventilation of the building caused by cross ventilation and warm air rising as wind passes over the chimney flue- causing suction Natural ventilation provided by gaps in poor fitting windows and doors water vapour