Guide · Rising Damp Brisbane
Not all damp is rising damp — and the fix is completely different for each. Treat the wrong cause and you waste money and the problem comes straight back. Here's how to tell rising damp from condensation and from a plumbing or roof leak.
Start here
Damp on a wall has three common causes, and they need three completely different fixes. A chemical damp-proof course stops rising damp — but it does nothing for condensation. Better ventilation clears condensation — but won't touch moisture wicking up from the ground. And a leak needs the leak found and fixed, not a damp treatment at all. So the first job is always to work out which one you're dealing with.
Rising damp
Affects ground-floor walls only. A fairly even horizontal tide-mark about a metre up, often with white salt (efflorescence) or fretting brick. Worst in older masonry with no working damp-proof course. Present year-round.
Condensation
Shows higher up, in corners and on cold surfaces — windows, tiled walls, behind furniture. Black spotty mould rather than salt. Worse in winter and in closed, unventilated rooms; water beads on glass.
A leak
A localised patch, anywhere on the wall (not tied to ground level). Near plumbing, wet areas, the roofline or a window. Appears or worsens after rain or heavy water use.
The tells
Height and pattern is the single best clue. Rising damp comes from the soil, so it can only affect ground-floor walls and it stops at a fairly even line about a metre up — the "tide-mark". If the damp is up near the ceiling, in a top-floor room, or in isolated patches, it isn't rising damp.
Salt vs mould. Rising damp carries ground salts, so it leaves a white, powdery bloom (efflorescence) and can make plaster blister and brick fret. Condensation leaves black, spotty mould on cold surfaces and in corners — mould, not salt, points to condensation.
Season and rooms. Condensation is worse in winter and in closed rooms (bathrooms, bedrooms with the door shut, behind wardrobes). Rising damp is there all year. A leak tends to track with rain or with using a particular pipe or fixture.
The reliable answer is a moisture meter. A specialist reads the moisture profile up the wall and across the room, which separates ground-sourced moisture (rising damp) from surface moisture (condensation) and pinpoints a leak — the guesswork removed.
Get the fix right
In Brisbane's older Queenslanders you can even have more than one at once — rising damp in the base walls and condensation in a closed-in room. That's exactly why we diagnose before we quote: we confirm the cause with a moisture meter, then treat the source.
We confirm the cause, extent and cost — with a written report you can act on.
Learn more →The permanent fix for true rising damp — a new damp-proof course in the wall.
Learn more →Where trapped underfloor moisture and poor airflow are driving the damp.
Learn more →Removing the ground salts and re-rendering so the damage doesn't creep back.
Learn more →Common questions
Yes — it's common in older Brisbane homes, especially closed-in Queenslanders. You might have rising damp in the ground-floor base walls and condensation in a poorly-ventilated room. We check for both during the assessment and treat each properly.
No. A dehumidifier can help with condensation by drying the air, but it does nothing to stop moisture wicking up from the ground. Rising damp needs the source stopped — usually a chemical damp-proof course — or it just keeps coming back.
It can contribute, but the black, spotty mould you see in corners, on windows and near ceilings is usually condensation, not rising damp. Rising damp more typically shows as salt staining, blistering paint and fretting brick low on the wall.
An on-site assessment with a moisture meter. We read the moisture up the wall and across the room and check the pattern, salts and construction — that separates rising damp from condensation and from a leak, so you fix the right thing. It's free.
Send us what your report said, or just tell us what you're seeing. We'll confirm whether it's rising damp, how far it's gone, and what it costs to fix — fast enough to meet your deadline.
We connect you with QBCC-licensed rising damp specialists across Brisbane. The assessment and written quote are free and no-obligation.
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Rising Damp