Common Property Defects
Foundation Failure
Problems in the foundations of a building may be detected by the presence of cracks in the walls. Foundation failure may be due to settlement (the downward movement of the soil due to the load of the building), subsidence (a downward movement caused by a weakening or change in the conditions of the soil) or hogging (an increase in the moisture content of the soil under a building). In severe cases underpinning may be required. This is where a new foundation is constructed at a greater depth under an existing building.
Movement in Walls
Problems can include:
- Thermal and moisture movement which may lead to vertical cracking in walls
- Material disintegration such as metal tie failure which may lead to horizontal cracking in walls
- Failure of lintels may lead to stepped cracking over window or door openings
- Vertical instability will lead to subsidence and diagonal stepped cracking in walls
- Bulging may occur where walls have no lateral stability
- Eccentric loading to walls may cause them to lean or crack.
Roof Problems
All of the junctions between the roof and other parts of the building have to be waterproofed. Problems with roofs can include poor ventilation, poor thermal insulation, blocked gutters and pipes and attacks from insects or fungal growth.
Faults in roofs often occur because of failures in jointings, such as verges (where a gable wall and the roof meet), ridges or hips which should be covered with ridge or hip tiles or valleys (where two sloping roofs met).
Flat roofs also have a number of problems to consider from failure of the joints of the covering materials (often felt) causing leaks or roof covering becoming brittle due to long term exposure to sunlight.
Pipes and gutters can cause a number of problems. Broken guttering or downpipes or corrosion of older guttering can cause saturation of walls and leaks into the property and defective drains can affect the property’s foundations.
Damp
When water rises from the ground and penetrates the structure above the ground, damp becomes present. Damp is a condition within a building where large amounts of water are present. It causes an unhealthy environment for both humans and materials. In damp conditions, some materials may break down and fail, timber will rot and metals will corrode. The main kinds of damp are penetrating damp, rising damp, condensation and water leakage.
Timber floors are particularly vulnerable to damp conditions and may suffer from wet rot and more damaging dry rot. Timer-framed windows are vulnerable to rot, which can lead to damp penetration.
Condensation may be caused by human activities and requires localised ventilation or extraction.
Fungal Growth
Fungi feed on timber and do not require sunlight or daylight to grow. High humidity will encourage fungal growth. As the fungus grows the timber will perish.
