Strata Repairs and Maintenance

Lesson 4: Water damage: find and stop the source

Goal: before you repair any water damage, find where the water comes from, stop it (or get it stopped) and make sure everything is dry.

Most of the patching and painting in a strata building is repairing water damage. And most repairs to water damage fail for one reason: someone painted over the stain before the leak was fixed or before the wall was dry.

1. Make safe

Water near electricity: if water is coming through a light fitting, a switch or a ceiling with a downlight, turn off that circuit at the switchboard (or call the electrician) before you touch anything. Keep people out.
A sagging ceiling: a bulging, water-filled plasterboard ceiling can collapse. Keep people out from under it. Lesson 7 shows how to drain it safely.
Stop the flow if you can: the lot’s stop tap, the building’s isolation valve, a bucket and a tarp.
Photograph everything before you clean up. It’s the insurance evidence.

2. Find the source

Practitioner tip: a stain shows where water ended up, not where it got in. Water runs along pipes, slab surfaces and framing, sometimes for metres, before it shows on a ceiling.

Cross-section of an apartment and the one above, with six numbered water sources: 1 the roof, gutters or a balcony above; 2 a shower or bath above with a failed seal or membrane; 3 an appliance hose or tap above; 4 a pipe in a wall or riser; 5 a window or door frame or a cracked wall; 6 condensation, which is not a leak at all. — The six usual suspects. Tap to enlarge.

Questions that narrow it down quickly:

Clue	Likely source
Only after rain, worse in storms	Roof, gutters, box gutter overflow, balcony, window or wall
Only after someone above showers	Shower seal, grout or membrane above
Constant, even in dry weather	A pipe: supply pipes leak all the time, waste pipes when used
Near an external wall, worse in winter, black speckles, no drip	Condensation
Low on a wall, a tide line, salt crystals	Rising damp or water ponding outside

Test one thing at a time. To check a shower above, ask the occupant to run only the shower for ten minutes while you watch the ceiling below, then the bath, then the basin. To check a window, run a hose on it while someone watches inside, starting low and working up.

A suspended ceiling tile with a large brown water stain and crumbling edges, above white tiled walls. — A typical leak stain: brown rings at the edges where the water dried, and a soft, crumbling centre. Photo: Atomicdragon136, CC BY 3.0

3. Leak or condensation?

Condensation looks like a leak but needs a completely different fix. Warm, moist air (showers, cooking, drying clothes inside, people breathing) meets a cold surface and turns to water. It shows up as:

black speckled mould spread evenly over a cold wall or ceiling corner, rather than a stain with a tide line
worse in winter, behind furniture pushed against external walls, in rooms with no exhaust fan
water running down the inside of windows in the morning

The fix is ventilation (exhaust fans that work and vent outside, opening windows, moving furniture off the wall), not patching. If it’s inside a lot, it’s usually the occupant’s issue, and a polite note with a fact sheet helps more than a repair.

4. Stop it, or get it stopped

Most sources of water are licensed work: plumbing, waterproofing, roofing. Your job is to find it, describe it clearly in a work order (Lesson 7 of the Strata Building Management course covers work orders), and make safe until the trade arrives. Some things you can fix yourself:

clearing a blocked gutter, balcony drain or box gutter outlet (from a safe position: Lesson 2)
resealing silicone around a bath, basin or window frame (Lesson 13)
tightening a loose hose fitting on a common laundry machine (taps and pipes are the plumber’s)

5. Dry it out

Health guidance: dry wet building materials within 24 to 48 hours to stop mould growing. After that, porous materials like plasterboard, insulation and carpet underlay often can’t be saved (Lesson 8).

Open up: lift wet carpet, remove skirting boards, drill small holes low in the plasterboard to drain trapped water.
Move air: fans, open windows, and a dehumidifier in closed rooms. Big events need a restoration company with commercial drying gear.
Measure, don’t guess. A moisture meter compares wet areas with a dry reference spot in the same material. Don’t patch or paint until the readings match the dry spot.

A yellow and blue moisture meter on a timber floor beside a white wall, with a probe on a cable resting on the floor. — A moisture meter. Take a reading in a known dry spot first, then compare. Photo: Asurnipal, CC BY-SA 4.0

The bottom of a white painted wall above a skirting, with paint bubbling and flaking away in a horizontal band. — Bubbling and flaking low on a wall: water coming up or in from outside, not down from above. Patching this without fixing the cause won't last. Photo: Kebabknight, CC BY-SA 4.0

6. Tell the strata manager

Water damage often becomes an insurance claim. Tell the strata manager the same day with photos, the cause (or what you suspect), what you did to make safe, and any lots affected. Don’t throw away damaged material until they say so: the insurer’s assessor may want to see it.

At Jacaranda Court

After a storm, the level 4 corridor ceiling shows a stain near the stairwell. It only happens in heavy rain. You go onto the roof (safely, with the roof access procedure) and find the box gutter outlet blocked with leaves and a tennis ball. You clear it, photograph before and after, and raise a work order to have a leaf guard fitted. The ceiling reads wet on the meter for nine days with a fan running. On day ten it reads the same as the dry corridor, and you move on to Lesson 7.

On the job 4

Pick the last three water stains in your building. For each, write down where the water actually came from. If you don’t know, that’s the job for this week.

Sources

US Environmental Protection Agency, A brief guide to mold, moisture and your home (dry within 24 to 48 hours)
NSW Health, Mould (condensation, rising damp and ventilation)
Better Health Channel (Victoria), Mould removal at home

Quick quiz

Pick an answer for each question. Nothing is recorded.

A brown stain appears on a corridor ceiling under a bathroom. What's the first job? Paint it with stain blocker Find and stop the source of the water Cut out the stained plasterboard
Show answer
Answer: Find and stop the source of the water. Until the water stops, any repair will stain or go mouldy again. Fix the cause first.
How quickly should wet plasterboard and carpet be dried to avoid mould? Within 24 to 48 hours Within a week It doesn't matter if it's painted
Show answer
Answer: Within 24 to 48 hours. Health agencies advise drying wet materials within 24 to 48 hours; after that, mould growth becomes likely.
Black spots on the inside of an external wall, behind a wardrobe, worse in winter, no leak found. What's most likely? A burst pipe Condensation from poor ventilation A roof leak
Show answer
Answer: Condensation from poor ventilation. Condensation forms on cold surfaces where air doesn't move. It is a ventilation problem, not a leak.

General education, not trade or legal advice. Licence limits, asbestos rules and window safety laws differ by state and change, so check your regulator before you quote or start. If a job involves electricity, plumbing, gas, waterproofing, fire doors or anything you think may contain asbestos, stop and get the right licensed trade.