One of the most essential requirements of any building is that it should stay dry, meaning that it must be damp proof. Failing to keep a building dry will result in the structure becoming unhygienic and unsafe to its inhabitants.
The reason for this is because certain diseases thrive in dampness, which will cause disintegration of the building at some stage.
Extensive inspection should be carried out during regular building maintenance to make sure that there is no dampness present in the structure.
Effects of dampness on a building
Apart from a damp creating unhealthy conditions and disintegration of the structure, it also causes unsightly patches, also known as efflorescence, to form on the wall’s surfaces. Timber also decays rapidly in the damp environment.
Different types of damp
It is important to note that there are several types of damp, each with their own unique way of being resolved and these are:
Rising damp is usually found in older buildings and is caused when moisture rises up through the porous stonework. In older buildings, the damp proof coursing either failed to do its job or was bridged, or was not used at all. Carried along with moisture are soluble ground salts including chlorides and nitrates. These behind are left in the stonework when the rising damp has evaporated, eventually causing damage to the building.
The treatment of rising damp normally involves injecting a chemical damp proof course using either injectable mortar-based grouts or liquid silicone-base materials into the affected area.
Vertical penetrating dampness
Poor building maintenance and building defects are the cause of vertical penetrating dampness. Blocked guttering and downpipes, leaking and roof defects are the most common things that cause this type of dampness. They are undoubtedly responsible for high levels of dry rot attacks in buildings.
Internal plumbing defects, poor external drainage, cracked and defective external coatings and blocked cavities, as well as inadequate door and window sealants, contribute towards vertical penetrating dampness.
Lateral penetrating dampness
This type of dampness occurs when external ground levels are higher than the internal floors of a building, causing moisture to penetrate the material of the walls. Basements are a good example of lateral penetrating dampness; the external walls of the basement are built against exterior ground. Flower beds, paths and pavements, abutting garden walls as well as raised gardens and soil levels, also cause lateral penetrating dampness to develop.
It depends largely on the level of dryness required and the proposed use, as to which method is used to control lateral penetrating dampness. Various types of tanking or vertical waterproofing are normally used and if applied properly, can result in dry floors and walls, by using waterproof render systems, cavity drainage membranes, or cement slurries.