There are a number of differences between traditional and modern day construction methods which should be considered when undertaking any repairs. The maintenance of traditional buildings has progressively relied on a diminishing pool of resources [knowledge, skills and materials]. This has resulted in the use of incompatible modern materials and methods, often to poor technical effect, leading to accelerated decay, as well as diminishing the character of the area.
(Generally, but not exclusively pre 1919)
Vapour permeable construction. Moisture is absorbed into the building fabric via “breathable’ materials. Moisture then evaporates off readily when drying conditions occur. A balance of conditions is maintained.
Relies on a sealed external envelope. Water finding its way into the construction does not readily evaporate.
Sometimes contains a damp proof course often a layer of slate.
Damp proof course prevents moisture transfer from the ground.
Good levels of ventilation reduces moisture build up and issues with damp. Voids in walls, floors, chimneys and flues all aid with the movement of air.
Largely sealed construction, with trickle vents in windows.
Composed of a limited range of natural materials with no preservatives.
Most construction products are mass produced, often treated with preservatives.
Relatively low levels of insulation.
Typically high levels of insulation.
Thick walls, usually stone, with large volumes of lime mortar and voids, which absorb water, which then evaporates off during drying periods.
Relatively slender wall construction with barriers and/ or cavities to prevent water penetration.