External coatings

External coatings refer to any substance applied to the exterior of a building’s walls. These can include renders, paints, or specialised impermeable materials designed to protect the building from weather elements, primarily water ingress.

Function: The primary function of external coatings is to provide a barrier against moisture, preventing rainwater from penetrating the walls. When intact and impermeable, these coatings can effectively shield the underlying materials from moisture-related damage.

Maintenance: Over time, external coatings can develop cracks and gaps, compromising their ability to repel water. Regular inspections and maintenance, such as filling cracks with appropriate materials and applying impermeable paint, are crucial to maintain their effectiveness.

Damp Implications: If water penetrates these coatings, it can lead to penetrating damp, visible as stains on internal walls. This dampness can also reduce the thermal insulation properties of the wall, increasing the risk of condensation and associated problems like mould growth.

Mitigation: To mitigate these issues, it is essential to maintain the external coatings and address any defects promptly. Smaller cracks can be filled with acrylic caulk, while larger ones may require mortar repairs. Additionally, improving internal ventilation and using vapour-active insulation can help manage humidity levels and prevent condensation.

Economic Impact: While some internal dampness may be tolerable, significant issues can affect property value and lead to costly and potentially unnecessary damp proofing treatments if not properly diagnosed and addressed.

In summary, external coatings are a vital component in the protection of a building’s fabric from moisture ingress. Proper maintenance and regular checks are essential to ensure their continued effectiveness in preventing damp-related issues.

Scroll to Top