Damaged or missing damp proof courses can allow moisture to transfer from the ground into the house slab and walls.
The dampness can be caused by ground level issues, such as the house being built too close to a retainer wall whilst being lower than the surrounding land. Even the slope of paving, if flat or directing water towards the house slab can cause significant issues as well as misdirected or poorly fitted storm water pipes . The house should never have a garden bed against any brick wall and should have a perimeter path around the entire house.
Dampness can also be caused from leaking bathroom floors and walls. Small cracks in the tiles, missing or cracked tile grout and the failure of the flexible sealant in the shower alcove. This is very common and the moisture is often transferred into surrounding rooms resulting in a musky smell. Of course if you are looking at an older house, the under floor brick dwarf walls or timber bearers, joists and stumps can also be effected. This dampness is very conducive to termite activity and contributes to the rusting of the ant caps that help prevent termites from entering your underfloor timber framework.
Another major issue with dampness if timber rot. This can be through faulty or poorly fitted roofing, rusted sheeting, rusted gutters or even leaking gutter joints. Often houses will over many years will settle and the gutter falls can now be incorrect resulting in ponding or overflowing guttering. A majority of timber rot is however simply due to lack of maintenance.
With detection tools such as a quality moisture meter, a thermal camera and cavity camera gear, these issues can be easily discovered and a solution recommended.
The costs for salt damp range from around $70-$95 per metre for a single brick wall up to $85- $105 per metre for a double brick wall. Stone walls less than 450mm thick approx $120-$150 per metre and thicker walls costing around $150-$200. Note that this price is just the treatment costs, you need to allow for the remediation work of the walls and of course the dumping costs associated with the required repair work. The treatment is warranted for approx 20 years.