Very commonly and loosley described as ‘damp surveys’, they are assessments of how the building envelope and its internal environment are affected by moisture, with regard to:
- Condition/design of (historic) drainage systems
- Contours/properties of the substrate on which the building is founded
- Properties and condition of the building materials and methods of construction
- The effects of previous alteration
- The growth of other (non-wood decay) fungi including moulds.
- Building use
- Environmental variables such as condensation, part of any damp survey, are considered more fully in the ‘Environmental Survey’.
The techniques employed are dependent on the degree of detail required and can include:
- Visual defect survey, invasive or non-invasive as appropriate.
- Recording moisture levels of building elements and environment (relative humidity)
- Removal of plaster/mortar/masonry samples for analysis
- Optically levelled/measured surveys
Would constitute the basis for a building specification. In the case of a residential building, this would detail all remedial work necessary to provide both a suitably habitable living environment and good standard of internal decor while ensuring this was not at the expense of the existing fabric.
The detail and tone of any recommendations or building specification would reflect the increased complexity and sensitivity almost always encountered with listed buildings.