Cracked Pipes: Signs, Causes and Repair Options for Melbourne Homes

A cracked pipe is rarely dramatic at first. It usually starts as a small leak or a slow drain and gets worse over weeks or months. Catching it early is the difference between a simple repair and a damaged floor, wall or garden. Here's how to tell if you might have one, what causes pipes to crack in Melbourne homes, and what the repair options are.

Signs you may have a cracked pipe

Water supply pipes (the pressurised pipes that feed your taps):

• A water bill that jumps with no change in how you use water
• The water meter ticking over when every tap is off
• Damp patches, bubbling paint or mould on walls and ceilings
• Warm spots on the floor, often a hot water pipe leaking under the slab
• Lower water pressure than usual

Drain and sewer pipes (the pipes that carry waste away):

• Drains that block again and again, even after being cleared
• Gurgling from sinks, showers or the toilet
• A sewer smell outside, especially near the gully trap
• Unusually lush, green patches of lawn over the drain line
• Sinking or soggy ground in the garden

What causes pipes to crack

Tree roots. Older clay and earthenware sewer pipes are joined in short sections. Roots find their way into the joints looking for moisture, then grow and split the pipe open.

Ground movement. Many parts of Melbourne sit on reactive clay soil that swells when wet and shrinks when dry. Over the years that movement puts stress on pipe joints and can crack older pipes.

Age and corrosion. Galvanised steel and old copper pipes corrode from the inside, and cast-iron drains rust over decades. Eventually the pipe wall gets thin enough to crack or pinhole.

High water pressure and water hammer. Water pressure above what your plumbing is designed for, or a loud knocking when taps shut off (water hammer), stresses joints and fittings. A pressure limiting valve fixes this.

Damage during building work. Digging, landscaping or renovations can crack a pipe without anyone noticing at the time.

How cracked pipes are found

Guessing where a leak is means unnecessary holes in walls and floors. The better approach:

• CCTV drain camera inspection for drains and sewers, which shows exactly where the crack is and how bad it is
• Non-invasive leak detection for pressurised water pipes, using thermal imaging and acoustic listening equipment to pinpoint the leak before anything is opened up

Repair options

Section repair. If the damage is in one accessible spot, the plumber cuts out the damaged section and replaces it.

Pipe relining. For cracked or root-damaged drains, a new resin liner is cured inside the old pipe. It seals cracks and joints without digging up the driveway or garden, and is often the cheapest option once you count the cost of excavation and reinstatement.

Replacement. If a pipe has collapsed, or the whole line is old and failing, replacing it can be the better long-term fix. A good plumber will show you the camera footage and explain the options before you decide.

What to do now

If you suspect a burst or badly leaking water pipe, turn the water off at the meter (usually at the front of the property) and call a licensed plumber. For a drain that keeps blocking, book a camera inspection rather than paying for repeat clear-outs. We cover 42 suburbs across Melbourne's eastern suburbs, and every job gets a fixed written quote before work starts.