Structural dampness is the presence of unwanted moisture in the structure of a building, either the result of intrusion from outside or condensation from within the structure.
Causes of dampness in buildings
- Rain penetration
- Level of site
- Drain ability of soil
- climate condition
- Defective orientation of building
- Moisture entrapped during construction
- Defective construction e.g. joints
A wide range of instruments and techniques can be used to investigate the presence of moisture in building materials.
The competence and experience of the person undertaking the damp investigations is often of greater importance than the kit he or she carries.
It is essential when investigating the potential for rising dampness to eliminate other sources of water ingress. Care must be taken to eliminate other potential sources of moisture, especially condensation in the colder months, and it is, therefore, essential to ensure that a full investigation is always undertaken. If any other sources are identified then these must be first eliminated before a proper assessment of any rising dampness can be made as it can be very difficult to distinguish between two or more interfering sources of water ingress.
The following gives a guide to on‐site routine procedures for the survey:
Dampness in building materials can be harmful to the structural integrity of buildings. If not treated properly water ingress can damage bricks and mortar, causing cracks in masonry, spalling and chipping.
Primary Internal Examination (Visible Signs):
- Fungal decay in skirting and/or other timbers.
- Peeling / blistering wallpaper, peeling / blistering paintwork.
- Mould growth, staining.
- Damp/wet patches, water droplets, water runs.
Different types of dampness need different treatments. It is therefore important to find out exactly which type of dampness is affecting the building, as the wrong treatment can in some circumstances do more harm than good.