What is Salt Damp?

salt damp repairs

Salt Damp is a major cause of decay to homes in South Australia.

Rising Damp and Salt Attack (Salt Damp) is a world-wide problem and it is a major cause of decay to masonry materials such as brick, stone and mortar throughout SA and Australia.

But what is it exactly?

The issue is actually two-fold. Firstly, the problem begins with Rising Damp.  Rising Damp occurs when porous masonry and/or soft mortar draws moisture by capillary action from the underlying soils and rocks. Lack of damp proof courses, or ones that have broken down or been bridged over time mean that the moisture can be drawn freely up a masonry wall.  Prior to 1980 many homes in South Australia were built without a damp proof course.

The second part of the problem is Salt Attack. This occurs as a result of the water containing salts in soluble form.  Ground water containing salt moves upwards through the masonry wall. Once the water reaches heat and air it will evaporate out of the wall.  But the salts remain both in the wall in a crystal form and on the wall surface . As the amounts of salt crystals grow it will rupture the masonry and cause it and the mortar to fret and crumble.

The problem is further intensified in South Australia as we have hotter, drier climates and our soils have a higher salinity level. This salinity leads to greater rates of transpiration through the wall and evaporation out of the wall. The remaining salts on the walls surface attracts further moisture from the atmosphere and draws this into the wall increasing the issue.

Previous treatments, maintenance or repairs have often made the problem worse or allowed the moisture to rise higher up the wall resulting in the damage you see today.

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