Rising damp questions, answered

Not on its own. That reading comes from a surface meter, which measures how well the wall conducts electricity. Salt left in old brickwork conducts even when the wall is dry, so a dry salty wall reads wet. The inspector reported what the tool can show. Naming the cause takes a different test.

Usually not, and this is the Newcastle question. Stepped cracking through brickwork is ground movement, not damp. In the declared mine subsidence districts around the Hunter it may be compensable through Subsidence Advisory NSW, which is a completely different process from a damp repair. We will tell you which one you are looking at.

Up to two hours on site and a written diagnosis for $450 plus GST. Moisture is measured at heights up the wall rather than at a single point, a sample is taken from the mortar behind the plaster, and the outside is checked for ground levels, paving and drainage. Treatment, if any is needed, is quoted separately afterwards.

You can. Be aware that an inspection which costs nothing has to be paid for somehow, and it is usually paid for by the job it recommends. We charge for the assessment so the finding can be “you do not need us”, which it sometimes is.

It can. Newcastle has a lot of terraces and semis, and a party wall has two owners and one damp problem. Treatment on one side of a shared wall often only half works. The assessment will say plainly whether your neighbour needs to be part of the conversation before any money is spent.

Salt is the difference. Coastal air carries it, and a wall that is already drawing groundwater collects salt from both directions. Salt is what perishes the mortar and pushes the paint off. It is why a Newcastle repair often involves taking render back and replacing it, not just injecting a barrier.

It tends to make things worse. Sealing the surface does not stop water getting into the wall, it stops water getting out. The damp then climbs higher or tracks sideways looking for somewhere to evaporate. Stripping a sealed wall back is a common and avoidable job.

Months, not days. Stopping the water climbing is quick. Getting the water that is already in there back out is slow, and the salt left behind does not leave at all without work. Anyone promising a dry wall next week is selling something.

Usually not. Home policies generally exclude gradual deterioration, and rising damp is gradual by nature. A burst pipe that suddenly soaked a wall is a different claim. Check your own policy — we cannot tell you what your cover says.

The specialist does, not us. We are a referral service. The work is done by an independent contractor holding the appropriate NSW Fair Trading licence and their own insurance. We arrange the assessment and nothing more.

Often yes, because it will come up in the buyer's building and pest report anyway, and an unexplained moisture reading costs more in negotiation than the fix usually does. A written diagnosis in hand is also worth something, even if you decide not to do the work.

It can be, particularly in a closed-up room in winter. Condensation shows as mould on cold surfaces and around windows, with no salt and no level tide line. Rising damp leaves a horizontal mark low on the wall, salt bloom under it, and it is there in summer too.

Rising damp is groundwater soaking up into a wall from the soil underneath it. Brick, stone and mortar are full of tiny holes. Water climbs those holes the same way it climbs up a paper towel. It stops about a metre up, where it dries off the wall as fast as it arrives. That is why the mark is a level line and not a patch.

Rising damp only happens on ground-floor walls, and it makes an even horizontal line about 600mm to 1.2m up. A leak makes a patch, usually higher, and usually worst after rain. Condensation shows up on cold surfaces and in corners, and it is worst in winter. A moisture meter and a look outside settle it in about an hour. Guessing is what costs people money.

A damp course is a waterproof layer built into a wall, just above the ground. It stops water climbing any higher. Older Newcastle houses were built with slate, lead or bitumen. Newer ones use plastic. A damp course can fail with age, or be bridged, which means water found a way around it.

Yes. The most common cause in a newer house is that the ground outside has ended up higher than the damp course. A concrete path, a garden bed, a slab or a re-levelled yard will do it. The water walks around the barrier. This is usually the cheapest kind to fix, because the fix is outside the house.

Damp walls grow mould. NSW Health says mould and damp indoors are linked to coughing, wheezing and asthma symptoms. It affects children, older people and people with asthma the most. Cleaning mould off the surface does not fix it while the wall is still wet.

No. A dehumidifier dries the air in the room. Rising damp keeps feeding water into the wall from the ground. The machine can make the room more comfortable while you sort the real cause out. It will not stop the water coming up.

Painting over damp is the most common mistake we see. Normal paint traps the water in the wall instead of letting it dry outwards. The paint then lifts off in sheets, often worse than before, and the salt comes with it. Fix the water first, let the wall dry, then paint.

An assessment with a written finding is $450. Injecting a new damp course runs about $170 to $330 a metre. Replastering a salty wall is about $120 to $260 a square metre. Sometimes the answer is only drainage or ground levels, which can cost less than any of that. Every fixed price quote follows an on-site assessment.

The physical work is usually a few days. The drying is the long part. A wall dries at roughly one month for every ten millimetres of thickness. A double brick wall can take most of a year before it is ready to paint. Finishing early undoes the work.

Usually not. Australian home policies commonly exclude gradual damage, wear and tear and lack of maintenance, and rising damp falls into that group. A sudden event is treated differently — a burst pipe, for example, is often covered. Read your own policy wording, and ask your insurer before you assume either way.

You can buy an injection kit. Home attempts usually fail for one of two reasons. Either the diagnosis was wrong and the wall never had rising damp. Or the salt already in the wall was left there, so the mark comes back through the new plaster. The chemical is the cheap part of the job.

Yes. NSW Fair Trading licenses residential building work. We only refer specialists who hold the licence their work needs. You can ask for the licence number and check it yourself on the Fair Trading register. A legitimate operator will not mind.

Yes. A building inspector will normally find it, and a buyer will ask for a price reduction or walk away. A written assessment is useful either way. If you are selling, it shows what the real problem is and what it costs. If you are buying, it stops you guessing at a number.

In practice, both of yours. Water does not stop at the boundary line. A shared wall also dries from one face instead of two, so it takes longer. The assessment covers the wall. The conversation with your neighbour usually has to happen before work starts.

No. A crack that steps down through the brickwork points at ground movement. Across much of Newcastle that can mean mine subsidence, and subsidence damage may be compensable through Subsidence Advisory NSW. Rising damp does not crack a wall in that pattern. A crack does let water in, so the two often turn up together.

Yes, and it lasts longer than people expect. Flash flooding out of the Throsby, Styx and Cottage Creek catchments soaks the ground around footings for weeks. Floodwater also carries salt into the wall. That makes it more damaging than everyday damp, and it often shows up months later.