Salts, such as nitrate and chloride, are common in building structures and groundwater. The salts are hygroscopic — absorb and retain moisture — especially in highly humid areas such as the coastal region. As groundwater rises, it evaporates and leaves the salts behind, leading to wall decay. Unfortunately, most homeowners cannot establish whether their houses are prone to salt damp. It is especially the case if the plasterwork on walls is still in good condition. Therefore, it is essential to hire a building inspector to check your house for salt damp vulnerability. Here are some critical areas that inspectors look at when examining for salt damp.
Damp Proof Barrier
When you book for on-site salt damp inspection services, the first thing that an inspector does is to establish whether your building has a damp proof barrier or not. It is a membrane that builders apply underneath concrete floors, preventing groundwater from rising through the walls via capillary movement. For best results, some builders install a damp proof membrane on walls. A structure without a damp proof barrier is vulnerable to salt damp; therefore, it allows an inspector to assess the walls and the floor for this issue.
Blistering Plasterwork
The walls are the next area that an inspector examines if they suspect the presence of salt damp. Typically, a wall will start to blister and bubble as groundwater rises and evaporates through the plaster. Bubbling plasterwork deteriorates the condition of walls structurally and esthetically. Notably, the extent of plaster bubbling depends on the concentration of salts in the groundwater. For instance, groundwater in coastal regions is saturated with salts, making it rise faster through the walls compared to groundwater in inland parts of the country. It is why interior walls of coastal properties are painted with damp proof paint due to its anti-condensation property.
Efflorescence
Hygroscopic salts readily absorb and retain moisture, evident from the bubbling and blistering on walls. However, as humidity levels drop, the humidity and water in the walls begin to evaporate, leaving behind a white furry material called efflorescence. It is the crystalline, powdery salt deposit visible on concrete or brick surfaces in salt damp affected homes. Typically, an inspector will take a sample for testing to determine the type of salts present in the rising damp. It is essential because different salts have varying effects on the structural integrity of a building.
Contact a salt damp treatment service for more information.
