Guidelines for determining whether a building is suitable for internal insulation
External walls in historic buildings are generally made of brick or natural stone, mortar, and plaster. Deterioration of these materials partly depends on the properties of the material itself and partly upon several environmental factors acting separately or in various combinations.
Before applying internal insulation, an inspection of the building façade is necessary to capture a visual impression of the façade and its protective state. The inspection will thus reveal hygrothermal structural damages and potential risks before renovating the building.
Typical damage risks in historic buildings are:
General
Infestation of timber components (fungus, mould, wood rot etc.).
Moisture damage due to defect water pipes, drainage, roof covering, water installation, etc.
Moisture damage from ground water due to missing sealing, horizontal barrier, etc.
Only external walls:
Efflorescence, salt deposits
Corrosion of steel lintels
Erosion of masonry joints
Spalling of external material layers (masonry, plastering etc.)
Interior surface mould growth due to low insulation standard, high moisture loads, etc.
Exterior surface algae growth e.g. due to leaking down pipes
When is internal insulation feasible?
If visual assessment, the evaluation of exposed areas and possible measurements has identified indication of moisture damage, the moisture sources need to be identified and eliminated. Read more about this in typical damages.
If the visual assessment show/indicate that insulation is feasible, the next step is either to move further to insulation systems, or to start collecting input data for using the RIBuild Insulation Calculator Tool.
Check the assessment tool below for the applicability of internal insulation, based on the presence of visual damage and material properties of the existing masonry wall.