Apartments · Strata · Homes · Commercial
Building Leak Detection
Water coming through a ceiling, under a skirting board or into the unit below? 1300 FINDLEAK finds where it is actually getting in: a leaking waste stack, the unit above, a balcony, a window frame, the facade, the roof or a pipe in the wall. We test each likely source until the leak is reproduced, then give you a photo report your builder, insurer or strata manager can act on. Building leak detection is from $398 inc. GST for the first hour.
Water coming in right now?
- If water is near lights, power points or the switchboard, turn the power off at the switchboard and keep clear.
- If it might be the unit above, ask them to stop using their shower, bath and taps, and let your building or strata manager know.
- If it's raining, it's likely rain ingress. Note which window, door or ceiling it comes through.
- Take photos and short videos of where the water appears and when. It helps us find the source faster.
Call 1300 346 353, 24/7. We'll tell you what to do now and when we can get there.
Where building leaks come from
In apartments and larger buildings, water often shows up a long way from where it gets in. It can run along a slab, down a waste stack or through a wall cavity before it appears in a ceiling or under a skirting board. That's why we test each possible source in turn instead of guessing.
- The unit above or next door: a shower, bath, laundry or kitchen
- Shared waste stacks and stormwater pipes in walls and ceilings
- Balconies, terraces and podiums leaking into the unit or car park below
- Window and sliding door frames, sills and flashings
- Cracked render, cladding joints and masonry in the facade
- Roofs, box gutters, cappings, flashings and roof penetrations
- Pressurised hot and cold water pipes in walls and slabs
- Groundwater, rising damp and poor site drainage at ground level
Why the first fix often doesn't work
In a review of 245 of our leak reports, 58% found more than one cause, and balconies were involved in 31%. A building can have a leaking balcony and a failed window seal at the same time. If only one is fixed, the leak keeps coming back. We test every likely path before we write the report, so the repair fixes the whole problem.
How we find building leaks
Tracer dye and water testing
We run water through one source at a time, often with fluorescent dye, to see which one reproduces the leak. It is the test that confirms the cause.
Thermal imaging and moisture mapping
Thermal cameras show cool, damp areas behind plaster and tiles. Moisture meter readings confirm what is wet and map how far the water has spread.
Tracing water between levels
Where water crosses from one level to the next, we test the unit above, the waste stack and the slab penetrations to find the exact entry point.
Case study: leaking waste stack in a 20-storey apartment building
A bedroom in a 20-storey apartment building had water coming in under the skirting board. Moisture readings were above 81%, in the wet range. We used thermal imaging, a moisture survey, acoustic listening, tracer gas and water testing to narrow it down.
Plumbing tests in the ensuite passed. When we water tested the kitchen sink waste, the water coming in increased, and thermal imaging confirmed it. The cause was holes in a 150 mm waste stack that served the ensuite toilet and the kitchen sink. Water was leaking from the stack into the base of the wall and out under the skirting. Pinpointing the source meant the repair could go straight to the stack instead of opening up walls to search for it.
Watch: finding an external wall leak in Melbourne
A two-year-old brick veneer home in Lysterfield had water getting into a rendered box overhang above the garage. Building movement had cracked the junction between the render and the flashing. Water got in through the crack, tracked along the sisalation paper behind the cement sheet and was trapped at the bottom of the box. The fix was an expansion joint at that junction, so the render can move without cracking again.
Building leak detection cost
Building leak detection
- Moisture survey and thermal imaging
- Water, dye, pressure or tracer gas testing as needed
- Source located and marked
- Written photo report for your builder, insurer or strata manager
Additional hour
$168 per hour in Sydney, Brisbane and the Gold Coast. Only if the job needs longer, for example several units or levels. We tell you before we go over.
Strata and commercial
For strata managers, owners corporations, builders and property managers. Larger buildings are quoted before we start.
Prices are for metropolitan areas. The Mornington Peninsula, Geelong and regional Victoria are priced by location. See all our leak detection prices.
How it works
Tell us what you see
Call or book online and tell us where the water shows up, when it happens and whether it's worse after rain or when a neighbour uses water. Photos help.
Arrange access
If the source could be in the unit above, next door or on common property, we'll tell you what access we need so the strata manager or neighbour can arrange it.
Survey and test
We map moisture and thermal readings, then test each likely source one at a time until the leak is reproduced and the cause is confirmed.
Report and next steps
We explain the cause and email a photo report. Your builder or trades can fix the right spot, or ask us to quote the repair and we'll book a return visit.
Rising damp, plumbing leak or rain ingress?
All three leave walls damp, but they behave differently. This is how we tell them apart.
| Type | What it usually looks like | How we confirm it |
|---|---|---|
| Rising damp | Damp along the bottom of the wall, often with a tide mark and white salt deposits. Doesn't change with rain or water use. | Moisture readings that fall away up the wall, and a check of the damp-proof course and outside ground levels |
| Plumbing leak | Wettest near a pipe, waste or fixture. Worse when that fixture is used, or constant if it's a pressure pipe. | Pressure testing, fixture-by-fixture water testing, acoustic listening or tracer gas |
| Rain ingress | Worse after rain, especially wind-driven rain. Often near a window, door, balcony, roof or crack in the render. | Water testing the window, balcony, roof or facade one area at a time, with thermal imaging |
| Condensation | Mould on cold walls and ceilings, worse in winter and in rooms with poor ventilation. | Moisture readings that are surface-only, and checking humidity and ventilation |
More on slab heave and rising damp and water damage and mould.
Signs of a building leak and what usually causes them
| Sign | Likely cause | How we find it |
|---|---|---|
| Ceiling stain or drip below another unit | Shower, bath or laundry in the unit above, or a leaking waste stack | Fixture-by-fixture water and dye testing upstairs, with thermal imaging below |
| Wet skirting or carpet along a wall | Leaking waste or water pipe in the wall, or water tracking along the slab | Moisture mapping, pressure testing and testing nearby wastes |
| Water at a sliding door or window | Failed sill, frame seal or flashing, or a balcony with poor falls | Water testing the frame and the balcony separately |
| Car park or podium ceiling dripping | Balcony, planter or podium membrane, or a leaking stack | Dye testing above and tracing the path through the slab |
| Damp patch on an external wall | Cracked render, cladding joints or a window above | Thermal imaging and water testing the facade one area at a time |
| Mould and a musty smell | Hidden leak, rain ingress or condensation | Moisture and thermal survey to separate a leak from condensation |
From our building leak jobs
Who we work for
- Strata managers and owners corporations, with pre-approved 30-day accounts
- Apartment owners and tenants with water coming from above, next door or outside
- Builders dealing with defect claims or checking work before handover
- Property managers who need the cause found and documented fast
- Insurers and loss adjusters who need the source of damage confirmed
- Homeowners with damp walls, stained ceilings or mould they can't explain
Need a report for a building dispute at VCAT, NCAT or QCAT? See our expert leak report. We're a family-run business, not a franchise, with Victorian licence 105159 and Queensland licence PD26669.
Related pages
Balcony leak detection · Shower leak detection · Roof leak detection · Water leak detection · Water damage and mould · Slab heave and rising damp · CCTV drain camera inspection · For owners corporations · VCAT expert leak report
Building leak detection FAQs
How much does building leak detection cost?
From $398 inc. GST for the first hour on site in metropolitan Melbourne, Sydney, Brisbane and the Gold Coast. Extra time, if needed, is $198 per hour in Victoria and $168 per hour in Sydney, Brisbane and the Gold Coast. That includes the testing, moisture and thermal survey, and a written photo report. Larger buildings with several units or levels are quoted before we start.
Water is coming into my apartment. Is it from the unit above?
Sometimes, but not always. Water can come from the unit above or next door, a shared waste stack, a balcony, a window frame or the building's facade. We test each likely source in turn, including the neighbouring unit's shower, balcony and waste pipes when access is arranged, until the leak is reproduced and the source is confirmed.
Who pays for a leak in a strata building?
It usually depends on where the leak starts. Leaks from common property, such as the roof, facade, shared waste stacks and often balconies, are generally the owners corporation's responsibility. Leaks from fixtures inside a lot, such as a shower or tap, are generally the lot owner's. Our report shows where the water starts so the right party can act. This is general information only; check your owners corporation rules or get advice for your situation.
How do you tell rising damp from a plumbing leak or rain getting in?
By the pattern and by testing. Rising damp sits low on walls, is fairly even along the wall and doesn't change with rain or water use. A plumbing leak is wettest near a pipe or fixture and gets worse when that fixture is used or pressure tested. Rain ingress gets worse after rain and is usually wettest near a window, door, balcony, roof or crack in the render. We map moisture readings and thermal images, then water test each likely source until one reproduces the leak.
Will you need to open up walls or ceilings?
Usually not. We find most leaks with moisture meters, thermal imaging, tracer dye, acoustic listening, tracer gas and water testing, without opening anything up. If a ceiling or wall is already open, or a small inspection hole is the only way to confirm a hidden pipe, we'll explain why before anything is cut.
Do you repair the leak as well?
Our visit is about finding and confirming the source, with a written photo report your builder, plumber, waterproofer, insurer or strata manager can act on. If you'd like us to, we'll quote the repair and return at another time to complete it, often with trusted independent trades.
Find where the water is really coming from.
From $398 inc. GST. Melbourne, Sydney, Brisbane and the Gold Coast. 24/7 phone line.
Trusted by builders, real estate agencies and strata managers across Melbourne, Sydney, Brisbane and the Gold Coast
Australian Home & Business Owners Choose Us
I'm Oliver Schulze, the director of 1300 FINDLEAK, a family-run company committed to solving all your gas and water leak problems. We pride ourselves on delivering the highest standards in customer outcomes and satisfaction, ensuring reliable and professional service every time.
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Use the enquiry button below and we will be in touch shortly or call us on 1300 346 353, and our friendly team will gladly help schedule an appointment at your convenience. We're here to make the process easy and stress-free for you!
Call 1300 346 353 - 24/7 for emergencies, office hours 7am–11pm, 7 days
Email admin@1300findleak.com.au — work orders and purchase orders welcome
Book online or submit a work order through our portal
We're a mobile service and come to your property. Our teams are based in Parkdale and Moorooduc in Victoria, Seaforth in Sydney, and Hope Island on the Gold Coast, covering Melbourne, Geelong, the Mornington Peninsula, regional Victoria, Sydney, Wollongong, Brisbane, the Gold Coast, Tweed Heads, Casuarina, Kingscliff and Byron Bay.
1300 FINDLEAK Pty Ltd · ABN 83 640 078 397 · VIC licence 105159 · QLD licence PD26669
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