Drain Relining vs Excavation | Which Costs Less in Fleet

A cracked or collapsed drain under your garden, driveway or extension leaves you with two choices: line it from the inside without breaking ground, or dig it up and replace the pipe. Contractors have a habit of defaulting to whichever method suits their kit, not necessarily your pocket. So here's a straight look at what each option costs, what drives those numbers, and what we'd actually choose if it were our own place in GU51 or GU52.

Spoiler: it's not always the no-dig route, even from a no-dig specialist.

The Numbers First

Cost ranges for drain work vary enormously by access, depth, pipe diameter, and what's actually wrong. That said, the industry lands in a fairly consistent band for a standard domestic job on a single run of 100mm or 150mm drain.

Those upper figures for structural excavation aren't a typo. Once you're breaking up a concrete slab, shoring a trench next to a wall, or dealing with a drain at 2.5 metres depth, you're in a different world. The soil removal alone, plus skip hire, plus reinstatement of block paving or tarmac, accounts for more than the pipe itself.

The relining figures assume accessible manholes at each end of the run. If access is difficult, the set-up time goes up and so does the cost. But it's still usually a fraction of the excavation price.

What a Liner Actually Is

Before judging the price, it's worth understanding what you're paying for. A cured-in-place pipe liner (CIPP, if you want the trade term) is a felt or fibreglass sleeve saturated with resin. An engineer inverts or pulls it into the damaged pipe from a manhole or access point, inflates it against the pipe wall with an air bladder, and leaves it to cure. UV light or ambient temperature sets the resin, typically over one to four hours depending on the product.

What you end up with is effectively a new pipe inside the old one. The internal diameter reduces slightly, usually by 6 to 8mm on a 100mm pipe, but the smooth bore of the liner often flows better than the original clay or pitch-fibre it replaced. Roots can't get back in. Water can't seep out. And you've done it without a single spadeful of soil.

A patch liner is the same idea but localised: a short sleeve, perhaps 300mm to 600mm long, bonded over a single crack or joint failure rather than lining the whole run.

What Drives Relining Costs Up

Length is the obvious one. A 6-metre run costs roughly twice a 3-metre run, subject to set-up costs being spread. Diameter matters too: a 150mm sewer line needs a larger, more expensive liner than a 100mm lateral drain from a single property.

Condition of the host pipe is the factor people don't think about. Relining works brilliantly on a cracked or root-infiltrated pipe that still has its basic shape. It does not work on a pipe that has collapsed entirely, has significant displacement at joints, or has lost structural integrity over a long section. Trying to inflate a liner inside rubble is pointless. That's when excavation becomes the right answer, not a default.

Pipe material plays a role too. Old pitch-fibre (common on 1960s and 1970s housing across Ancells Farm, Pondtail, and Velmead) tends to delaminate and go oval rather than crack cleanly. Depending on how far the deformation has progressed, it can still accept a liner, but it needs careful assessment.

What Drives Excavation Costs Up

Depth is the big one. A drain at 600mm below garden soil is a morning's work. At 1.8 metres you need shoring, a larger machine, and longer on site. At anything approaching 3 metres you're in confined-space territory with a completely different set of equipment and risk protocols.

Surface is equally important. Digging through open lawn costs very little to reinstate. Digging through a block-paved driveway on Elvetham Heath, through a resin-bound path in Crookham Village, or through tarmac anywhere near a road costs serious money. The drainage work might be £1,500; the reinstatement of matching blockwork or a seamless resin surface can add £2,000 to £4,000 on its own.

Proximity to structures is the other killer. If the damaged pipe runs beneath a conservatory base, an extension, or (in some of the older properties around Church Crookham and Hartley Wintney) beneath the house itself, excavation isn't just expensive. It carries genuine structural risk. Lining becomes not a preference but a necessity.

The Cases Where We'd Dig

Relining is our default tool. But there are genuine situations where excavation is the right call.

Full collapse over a significant section. If a stretch of pipe has dropped, buckled, or filled with debris, there's nothing for a liner to sit against. Survey footage showing displaced joints at more than about 20mm of offset or sections with no visible bore means the pipe needs to come out.

Root damage that's created voids. Root intrusion is usually relining territory. But if the roots have worked into the pipe over decades and created large voids in the surrounding soil, you've got a subsidence risk regardless of whether you line it. Filling the pipe without addressing the cavity around it stores up trouble.

Pipe that's been repaired badly before. We occasionally survey pipes that have had multiple cement-injected repairs, mismatched replacement sections, or older pitch-fibre sleeves pushed over the top of other damage. When the history is that messy, a clean excavation and replacement with modern PVC-u pipe gives you a known starting point. Trying to line over multiple previous interventions is asking for problems.

Access to manholes is completely blocked. Relining needs somewhere to insert and somewhere to anchor. Properties with overgrown, built-over, or simply missing manholes sometimes can't accommodate it without excavation to create the access first anyway.

The Cases Where We'd Reline

Root infiltration through joints is the classic. We see this constantly on the Victorian and Edwardian clay pipe networks around Dogmersfield, Crondall, and Odiham. The pipe is structurally sound; the roots have just found the gaps at the joints. Clean out the roots with our cutter, flush with high-pressure jetting, line it. Done, and the 20-year guarantee on the remedial work means you're not revisiting it.

Cracks in otherwise-intact pipe are another clear win for lining. A longitudinal crack from ground movement, a circumferential crack from a point load above, even a small section where the pipe has gone slightly oval: all of these respond well to a liner if the basic structure is there.

Drains under driveways, patios, or extensions are almost always better lined. The cost differential against excavation and full reinstatement is usually £2,000 to £5,000 in favour of relining, and there's no risk of damaging the surface finish or the structure above.

Speed matters for commercial clients too. A business in a Fleet town centre unit or an office park on the Ancells Park estate can't afford a day or two of trench-digging. A relining job is typically in and out in a single working day.

Why the Survey Has to Come First

Neither you nor any contractor should be deciding between these options blind. A CCTV drain survey, at £150 to £300 for a standard domestic run, produces footage of exactly what's wrong, where it is, and how bad it is. Without it you're guessing, and guessing wrong in either direction costs you money.

Guessing towards relining when excavation was needed means the liner fails, you've wasted the cost, and you're digging anyway. Guessing towards excavation when a liner would have done means you've torn up your driveway unnecessarily.

The survey also tells you the pipe's gradient, whether there are any bellied sections holding standing water, and the condition of the manholes. All of that informs the repair specification. It's not an upsell, it's the information you need to spend the rest of the money sensibly.

We run CCTV surveys across Fleet and the GU postcodes as a standalone service. The footage is yours to keep, and if a repair follows, the survey cost is deducted from the job price.

How to Spend the Money Sensibly

Get the survey. That's the only firm rule. After that:

• If the pipe has its basic shape and the damage is cracks, joints, or roots, get a liner specification and a price. Compare the total (liner plus any access work) against excavation plus full reinstatement of whatever's above it.
• If the pipe is collapsed, severely displaced, or buried under structures with genuine access problems, get an excavation quote, but make sure the quote includes reinstatement to the same finish, not just soil backfill.
• Ask any contractor what guarantee they put on the repair, not the clearance. Our remedial work carries a 20-year guarantee. That should be a standard expectation.
• If a contractor recommends full excavation without having done a camera survey, push back. Either they don't have the survey kit, or they don't have the lining kit. You should know which before you decide.

On our own house? We'd survey it, and if the pipe had any structural integrity left, we'd line it. The cost saving is real, the disruption saving is obvious, and the liner outlasts most of the pipe it goes into. But we wouldn't line a collapsed pipe just to avoid digging. Some jobs need a spade, and that's fine.

Drainsco covers Fleet and all the GU51 to GU52 postcodes. Engineers are available 24 hours a day, seven days a week. There's no call-out fee, and you'll get a clear price before any work starts. If you're not sure which way a repair should go, the survey is the right first call.