What are some signs of urban salinity?
The sort of tell-tale signs are dampness under houses, vegetation dying, roads breaking up, salt in table drains and in the gutters of roads. What tends to happen with older houses is a combination of the damp course failing and the groundwater table rising to near the surface. A brick is like a sponge and it will draw the water up and in some places where the damp course is maybe 60, 70 years old the water will rise up to two metres up the wall. If that wall is exposed to sunlight on a regular basis then salt crystals will form and that will start to fret away the surface of the brick. Over a period of time with that continuous wetting up and drying by the sun the structure of the bricks disintegrates completely and you’ll end up with holes in the bricks you can put your fist through. It also impacts on the render inside the house and we start to see render falling off inside the houses, which can be up to a metre inside the house you will get render falling off.
