Water moves the salt. The salt does the damage. Treating one without the other is why walls come back.
Talk it throughRising Damp Perth arranges damp assessments across Perth metropolitan area.
Dissolved salts travel up a wall with the groundwater and are left behind as it evaporates. Crystallising inside the pores, they expand with enormous local force — enough to push render off and take the face off a brick. The wall is not being dissolved; it is being levered apart from the inside.
From the ground, like everywhere. And on the coast, from the air: salt spray lands on the wall and works inward. Scarborough, Cottesloe and Fremantle carry both loads at once, which is why surface damage there can be well advanced while the moisture reading is only moderate.
Contaminated render is removed rather than covered. Where contamination is heavy the wall may be poulticed to draw salts out before anything new goes on. The replacement is a salt-retarding, breathable system that holds the remaining salts back from the finished surface.
What follows is indicative. Every one of these is a range because the wall decides, not the website.
| Work | Indicative range | What it covers |
|---|---|---|
| Assessment and moisture survey | $250 - $450 | Moisture readings across the affected walls, a look at ground levels and drainage, and a written finding on which of the four common causes you actually have. |
| Chemical damp-proof course, per metre | $180 - $340 | Injected into the mortar course. Limestone generally sits at the upper end because it takes more material to achieve a continuous barrier. |
| Salt-retarding replaster, per square metre | $120 - $260 | Old contaminated render off, breathable system on. Frequently the larger part of the job. |
| Drainage and ground-level correction | $900 - $6,000 | Lowering paving, cutting back garden beds, adding a drain. Where the cause is bridging rather than a failed damp course, this is the fix. |
| Subfloor ventilation improvement | $1,200 - $4,500 | Less common in Perth than Brisbane because fewer homes have a ventilated subfloor, but it applies to the older timber-floored stock. |
Prices are indicative ranges only. Limestone, double brick and rendered walls each cost differently to treat, and every fixed price follows an on-site assessment.
We arrange assessments across the Perth metropolitan area, including:
Rising Damp Perth