RISING DAMP AND OTHER COMMON BUILDING DEFECTS
Common building and construction defects in a home or unit are damp or dampness within the structure. The damp in a house can be rising damp in older buildings. Houses constructed prior to 1910 can also suffer from penetration or lateral dampness. Descending damp can also occur within these buildings. The above dampness is very different to condensation damp or mould.
To correctly determine the type and source of damp within a building, an experienced building consultant, or building surveyor, must inspect and report on the building. The building inspection will check the type of construction, including renovations and additions. Also any DIY works must be checked for standard of construction, as well as dampness in walls. As the value of real estate can be affected, then an adequate inspection by a building expert is essential. The dampness is usually not a result of engineering defects, but usually bad building practices, builder mismanagement, deterioration of the building due to age or lack of building maintenance.
This usually occurs in older buildings where the damp course in the walls has deteriorated due to age. Where the floor level is close to the ground, the degree of rising dampness will be greater. Removal of the original timber floors and replacement with a concrete slab can also course rising damp. An example of rising dampness is
Penetration or lateral damp
This usually occurs in buildings constructed prior to 1910 where a solid wall construction is provided. The paint on the external surface is the waterproof coating and must be retained in reasonable to good condition. This would also include the brick parapet walls above roof level. When the paint deteriorates in these areas, the rainwater is absorbed into the walls and is absorbed through the brickwork and will affect the internal plaster. In prolonged exposure, the plaster can soften and deteriorate on the inside of the building.
Condensation damp or mould
This is usually not as a result of a building defect, but how the building is lived in. Various factors or situations provide an environment where mould appears. The causes and factors are many and varied and can only be determined by a suitably experienced and qualified building consultant or expert.
Damp in units
Many recently constructed unit buildings suffer from damp or water ingress. The causes and reasons are varied and include the following:
- defective waterproof membranes. This is usually to external balcony and/or planter boxes. The membranes fitted may have a limited design life or not be provided with construction methods to allow the building to 'move' and allow for the initial "settling in" period.
- defective cavity flashings to brickwork. Incorrectly installed, lack of installation and poor attention to detail of cavity flashings can result in water entry to a unit building. Also lack of weep holes in the required locations can lead to water entry to a unit.
Water seepage to lower garages
This can occur for various reasons, but often seepage or water entry occurs to garage levels through cracks in the concrete slab above. The water entry occurs due to inadequate, incomplete or the non-installation of waterproof membranes to the top surface of the concrete roof above. This is more common where landscaping, paving or planter boxes are located above. Examples water seepage to lower garages are
This is a hard lime coloured, like staining and/or formations usually at the slab edges. Sometimes it can appear in the grout joints on patios or to an external shower. Efflorescence is difficult to remove and can reappear after cleaning. The efflorescence is a result of chemicals and other formations within the sand and cement bed being washed out over time.
What to do
An experienced building consultant, building surveyor or building expert will need to inspect and report on the causes of the building problem or defect. Every defect must be assessed on an individual basis so that the correct building remedial works are carried out.
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