Twenty years ago, a damaged drain meant excavation. Trenches across the lawn, paving lifted, full replacement. These days, drain relining can fix many problems without any digging. Here is when each makes sense.
What relining is
A flexible liner impregnated with epoxy resin is fed into the damaged pipe. Inflated to fit tight against the pipe walls. The resin cures (sometimes with hot water, UV light, or just time). Result is a smooth, jointless pipe inside your original pipe. Roots cannot grow through it. Most leaks are sealed.
When relining works
Pipes with multiple cracks or root intrusions where the structural integrity is mostly intact. Long straight sections of pipe where the liner can be fed easily. Pipes where digging would be expensive (under driveways, slabs, or established gardens).
When relining does not work
Fully collapsed sections of pipe. Severe misalignment where the existing pipe no longer makes a coherent path. Pipes that need to be moved or redirected. Very tight bends where the liner cannot follow.
Cost comparison
Relining: typically $300 to $500 per metre. Plus setup and access fees of $500 to $1,500. For a typical 5 metre section: $2,000 to $4,000.
Excavation and replacement: highly variable. Easy access (open garden, shallow pipe): $200 to $400 per metre plus setup. Hard access (under concrete, deep pipe): $500 to $1,200 per metre plus setup. Plus the cost of restoring the surface (relaying lawn, paving, concrete).
Beyond the dollar cost
Relining is usually a one or two day job. Excavation can be a one or two week disruption with trucks, equipment, and ongoing site mess.
Relining keeps your garden, paving, and driveway intact. Excavation disturbs all of them and the surface restoration is rarely perfect.
What we recommend
Get a CCTV inspection first to understand exactly what is wrong. Then get quotes for both relining and excavation. For most Melbourne drain problems we see, relining is the right answer. Excavation is reserved for collapsed pipes or major redesign.
A reputable plumber will tell you honestly whether your specific problem suits relining. If they only ever do one option (always reline or always excavate), get a second opinion.