Two very different ways to stop rising damp — compared honestly on cost, disruption, lifespan and where each one actually belongs, by Rising Damp Sydney's licensed specialists.
Call 02 9158 9901For most Sydney brick homes, chemical DPC injection is the right fix — it costs $150–$400 per linear metre, needs no structural work, and reputable installers back it with long warranties. A physical membrane (mechanical DPC) is the heavy-duty option at $800–$1,500 per linear metre, reserved for thick stone walls, heritage rubble construction, or where injection can't achieve full penetration. Rising Damp Sydney installs both — the free inspection tells you which your walls actually need before you spend anything.
| Factor | Chemical DPC Injection | Physical Membrane (Mechanical DPC) |
|---|---|---|
| Cost | $150–$400 /lm | $800–$1,500 /lm |
| How it works | Silane/siloxane cream injected into drilled holes cures inside the brick to form a water-repellent barrier | Masonry course is physically cut in sections and a polyethylene or copper sheet inserted |
| Disruption | Low — drilling and injection, typically 1–2 days per wall | High — structural work done in alternating sections over days to weeks |
| Best for | Standard single and double-brick walls — the vast majority of Sydney homes | Thick stone, heritage rubble, irregular walls where cream can't fully permeate |
| Lifespan | Decades — long product warranties are standard | Effectively the life of the building |
| Main risk | Failure if wall is too thick or dense for full penetration — a diagnosis problem, not a product problem | Cost, and structural risk if done by anyone other than an experienced specialist |
If your home is standard brick construction — a terrace, Federation double-brick, or later — injection is almost always the answer. The cream cures inside the masonry to form a hydrophobic zone in the wall itself, the work takes a day or two, and the wall is replastered with salt-resistant render afterwards. This is the treatment Rising Damp Sydney performs on most jobs, and it's why most residential treatments land in the $800–$3,500 range rather than five figures. See the full cost guide for detailed pricing.
Physical DPC replacement earns its price tag in three situations: very thick or stone walls where injection fluid can't reach the full wall width, heritage rubble construction with voids that swallow cream unpredictably, and jobs where heritage or insurance requirements mandate a physical barrier. It's genuinely structural work — the wall is cut and re-supported in sections — which is why it should only ever be done by an experienced remedial specialist.
Injecting a wall that needed a membrane means the damp returns and you pay twice. Paying for a membrane on a wall that injection would have fixed wastes thousands. This is a diagnosis decision, not a preference — which is why Rising Damp Sydney inspects free and quotes the method your wall construction actually requires, backed by a lifetime workmanship guarantee.
On standard brick walls, yes — correctly installed injection creates a barrier within the masonry that performs comparably for decades, at a fraction of the cost and disruption. On very thick or irregular stone walls, a physical membrane is more reliable.
Decades. The cured barrier bonds to the mineral structure of the wall, and long manufacturer warranties are standard on quality systems installed by licensed professionals.
No — and this is where cheap quotes go wrong. Very thick walls, rubble-filled cavities and some stone construction can't be fully permeated by injection cream. A proper inspection determines wall construction before any method is quoted.
Rising Damp Sydney inspects free, confirms your wall construction, and quotes the right method with a fixed upfront price and lifetime workmanship guarantee.
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