Few words strike more dread into a homeowner than hearing a plumber say the broken pipe runs straight under your driveway, bathroom floor, or house slab, and that digging it up is the only way to fix it. The good news is that in most cases, it isn’t. Pipe relining in Melbourne was developed specifically to solve this exact problem, repairing a damaged pipe from the inside without needing to break through concrete, tear up paving, or excavate a trench across your property. This guide explains how relining actually works when the damaged pipe sits beneath a slab or driveway, and what to realistically expect from the process.
Can a Pipe Under Concrete Be Relined?
Yes, and this is one of the main reasons pipe relining exists as a repair method in the first place. Relining works by inserting a resin-saturated liner through existing access points and curing it in place to form a new pipe inside the damaged one, which means the work happens entirely within the pipe itself rather than requiring access from above. A pipe running under a driveway, a bathroom floor, or a house slab can typically be relined without disturbing whatever sits above it, provided there is a suitable access point to work from.
Can a Sewer Underneath a Driveway Be Repaired Without Digging?
In most cases, yes. Sewer lines running beneath driveways are one of the most common applications for relining, specifically because traditional excavation in this location is so disruptive and costly. Rather than breaking up the driveway surface to expose the damaged section, a plumber can access the pipe through an existing inspection opening elsewhere in the line, feed the liner through to the damaged section, and cure it in place, leaving the driveway completely untouched.
Can Pipes Beneath a House Slab Be Accessed?
Yes, this is another common and well-suited application for relining. Pipes running beneath a house slab are particularly difficult and expensive to access through traditional excavation, since it would typically mean breaking through the concrete floor inside the home itself. Relining avoids this entirely in most cases, working through existing access points in the drainage system rather than requiring entry from directly above the damaged section.
Does the Concrete Need to Be Cut?
In the majority of cases, no. The entire advantage of relining is that it works through the existing pipe network via inspection openings, gully points, or other access points already present in the drainage system, rather than requiring new access to be created through concrete. There are some less common scenarios, such as a complete pipe collapse or a situation with genuinely no usable access point anywhere along the line, where limited excavation or a small access point may still be needed, but this is the exception rather than the standard approach.
How Does the Liner Get Into the Pipe?
A flexible liner, saturated with a specialised resin, is fed into the damaged pipe through an existing access point, then positioned precisely over the section requiring repair using inflation and specialised equipment to press it firmly against the internal pipe wall. The resin is then cured, using heat, UV light, or in some cases simply time, depending on the specific relining technology being used, hardening into a smooth, durable new pipe wall within the old, damaged pipe. The result is a seamless new internal surface that no longer relies on the structural integrity of the original damaged section.
What Access Points Are Needed?
Access is generally gained through existing fixtures in the drainage system, such as an inspection opening, a maintenance hole, a gully trap, or occasionally a toilet pan or other connected fixture, depending on the configuration of the property’s plumbing. A CCTV inspection is used beforehand to confirm the condition and layout of the pipe, and this same inspection helps identify the most suitable existing access point to work from before any relining begins.
What Happens if There Isn’t an Existing Inspection Opening?
If a property genuinely has no suitable existing access point along the affected pipe run, a plumber may need to create one, typically a small, localised opening rather than the extensive excavation traditional pipe replacement would require. This is a far smaller intervention than digging up an entire driveway or breaking out a full section of slab, and in many older properties, an access point can often be found or created without needing to disturb significant concrete or paved areas.
Can Junctions Underneath the Concrete Still Be Reopened?
Yes. Once the liner has cured in place, any junctions where branch pipes connect into the relined section are reopened using a robotic cutting tool operated remotely through the pipe, guided by camera. This allows junctions beneath a driveway or slab to be properly reinstated without any need to access them from above, since the entire process is carried out from within the pipe itself.
Can Both Sewer and Stormwater Pipes Underneath Concrete Be Relined?
Yes, relining is suitable for both sewer and stormwater pipes running beneath concrete, driveways, or slabs, provided the pipe’s condition allows a liner to be properly installed. A CCTV inspection will confirm whether a specific pipe, sewer or stormwater, is a suitable candidate for relining or whether its condition requires a different approach.
What Happens if the Pipe Has Completely Collapsed?
A fully collapsed section of pipe generally cannot be relined in the same way as a cracked or structurally intact but damaged pipe, since relining requires enough of the original pipe shape to remain for the liner to be properly positioned and cured against. In this specific scenario, some degree of excavation may be unavoidable for that particular section, even if the rest of the affected pipe run is still suitable for relining. A CCTV inspection will clearly identify whether collapse has occurred and to what extent, allowing a plumber to advise honestly on whether full relining, a partial excavation combined with relining, or another approach is the right solution.
How Much Does Relining Under Concrete Cost?
Relining under a driveway or slab is generally priced similarly to other relining jobs, based primarily on pipe length, diameter, the number of junctions, and how much preparation work is needed, rather than carrying an automatic premium purely because it runs under concrete. Where cost can increase is if access is more difficult to establish, or if a small access point genuinely needs to be created due to a lack of existing openings. As a general guide, Australian relining costs commonly range from a few hundred to over a thousand dollars per metre depending on these factors, though an accurate figure requires an on-site assessment and CCTV inspection of your specific pipe.
How Does That Compare With Concrete Demolition and Reinstatement?
This is where relining’s value becomes most obvious. Traditional excavation beneath a driveway or slab involves breaking out and removing the existing concrete or paving, excavating to reach the pipe, carrying out the repair, backfilling, and then reinstating the surface, new concrete, paving, or landscaping, to match what was there before. The reinstatement cost alone, replacing a driveway or restoring an established garden bed, can rival or exceed the cost of the pipe repair itself. Relining avoids this entirely in most cases, since the surface above the pipe is never disturbed, which is a major reason it has become the preferred solution for pipe damage running beneath concrete, driveways, and house slabs.
How Long Is the Driveway Unusable?
Significantly less time than traditional excavation would require. A typical relining job, including CCTV inspection, preparation, liner installation, and curing, is often completed within a day for a standard residential job, meaning your driveway is generally usable again far sooner than if it had to be broken up, repaired, and reinstated. Larger or more complex jobs involving multiple sections or junctions may take longer, but even then, the timeframe is generally measured in days rather than the weeks that full excavation and concrete reinstatement can involve.
A Genuine Alternative to Digging Up Your Property
Being told a broken pipe runs under your driveway or house slab does not automatically mean your property needs to be dug up to fix it. In most cases, relining offers a way to repair the pipe from the inside, avoiding the cost, disruption, and mess of breaking out concrete and reinstating it afterward.
If you have a damaged pipe running beneath a driveway, slab, or paved area, our team can carry out a CCTV inspection to confirm whether relining is suitable for your specific situation, and provide a clear, itemised quote. Call King and Sons Plumbing on 03 9993 7122, available 24 hours a day, 7 days a week, across Melbourne.
