Rising Damp Treatment in Sydney

Stop Moisture from Damaging Your Home

Eliminate rising damp in your Sydney home with expert solutions. Prevent structural damage, mould, and musty smells. Trusted local damp specialists.

What is Rising Damp?

Rising damp is a serious moisture problem that affects many Sydney homes, especially older properties. It occurs when groundwater seeps up through porous building materials like bricks, mortar, or stone due to capillary action. This moisture can rise up to 1.5 metres in your walls and floors, bringing salts, mould, and long-term damage with it.

If left untreated, rising damp can lead to:

  • Crumbling plaster or bubbling paint
  • Peeling wallpaper
  • Timber rot and decay
  • Persistent musty odours
  • Visible salt deposits (efflorescence)
  • Mould growth and health issues
  • Damage to electrical systems

Sydney’s older terrace homes, Federation-style houses, and heritage buildings are especially prone to this problem due to lack of modern waterproofing.

What Causes Rising Damp in Sydney?

Rising damp typically happens due to one or more of the following:

  • Missing or Failed Damp-Proof Course (DPC): Most modern buildings have a DPC installed during construction. Older homes may not have one, or the barrier may have deteriorated over time.
  • Poor Subfloor Ventilation: Inadequate airflow beneath the home can increase humidity levels, exacerbating rising damp and allowing moisture to linger.
  • Blocked Drainage Systems: Overflowing gutters, leaking pipes, or poor site drainage can direct water toward your home’s foundations.
  • High Water Table or Wet Soil Conditions: Many Sydney suburbs — especially those near creeks, coastlines, or clay-heavy soil — are naturally prone to moisture accumulation.

 

How to Identify Rising Damp

Here’s what to look out for:

Visual Signs:

  • Peeling or bubbling paint near skirting boards
  • Salt marks or white powder on walls (efflorescence)
  • Mould growth at the bottom of walls
  • Watermarks or damp patches

 

Smell & Sensation:

  • Persistent musty odour in rooms
  • Damp feeling in floors or walls

 

Structural Signs:

  • Timber decay in skirting or floorboards
  • Warping or softening of wall surfaces

 

If you suspect any of these, you may be dealing with rising damp and should act quickly to prevent escalating structural damage.

How Sydney Subfloor Ventilation Treats Rising Damp

At Sydney Subfloor Ventilation, we offer comprehensive, long-term rising damp solutions using the most effective techniques for Sydney homes:

1. Rising Damp Assessment & Diagnosis

We start with a full inspection of your property, checking moisture levels in walls, floors, and subfloor areas using industry-grade moisture meters.

2. Installation of a New Damp-Proof Course (DPC)

We install or replace a chemical or physical DPC to stop further moisture from rising through your walls. Common methods include:

  • Chemical Injection Damp-Proofing – a water-repellent barrier injected into the wall

  • Membrane-Based Barriers – a durable plastic sheet installed at the base of walls during renovations

3. Wall Replastering & Salt Removal

Once moisture is under control, we remove and replace salt-contaminated plaster and wall finishes to prevent reoccurrence.

4. Improving Subfloor Ventilation

To prevent moisture buildup beneath your floors (which worsens rising damp), we install energy-efficient ventilation systems for improved airflow.

5. External Drainage Fixes

If needed, we’ll inspect site drainage and guttering to ensure water is directed away from the building.

Six Reasons to Fix Rising Damp Immediately

1. Prevent Costly Structural Damage

Rising damp weakens bricks, mortar, and timber over time. Early intervention can save you from extensive (and expensive) repairs.

2. Protect Indoor Air Quality

Moist environments are breeding grounds for mould, mildew, and bacteria. Fixing rising damp improves air quality and reduces allergy risks.

3. Avoid Electrical Hazards

Damp walls increase the risk of electrical shorts, power outages, or dangerous shocks — especially when moisture reaches wiring.

4. Improve Home Comfort

Rising damp makes interiors feel cold and clammy. A dry home is a warmer, healthier, and more comfortable space.

5. Maintain Property Value

Buyers are wary of moisture issues. Treating rising damp protects your resale value and gives peace of mind to potential buyers.

6. Comply with Building Codes

If you’re renovating or renting, treating damp problems ensures compliance with Australian building and health regulations.

Local Experts for Sydney Homes

With years of experience fixing moisture issues in Sydney’s homes, we understand the city’s unique architectural styles, climate challenges, and soil conditions. From Inner West terrace homes to Northern Beaches residences and South Western Sydney cottages, we tailor rising damp solutions to each suburb and structure.

Compatible with Heritage Buildings

Many of our clients live in heritage-listed or character homes. We use non-invasive damp proofing methods and traditional plastering techniques that preserve your home’s appearance while addressing moisture problems discreetly and effectively.

Why Choose Sydney Subfloor Ventilation?

  • Local experts with moisture management certification
  • Specialised in rising damp & subfloor ventilation
  • Custom solutions for all property types
  • Transparent pricing and honest assessments
  • Trusted by homeowners across Sydney