Introduction

If drain repair jobs keep boomeranging back as callbacks, you’re not alone. The tricky bit is knowing when jetting and patching will hold, and when you’ve got to dig. In this Part 2 drain repair guide, we’ll walk through how to diagnose properly, prep the pipe, pick the right method (no-dig lining, patch, or excavation), and sign off with confidence. You’ll see practical field steps, measurements that matter, and the quality checks that prevent disputes. We’ll also touch on pricing and how to speed up proposals and sign-offs without living in your inbox.

Quick Answer: Drain repair that lasts starts with a solid CCTV diagnosis, thorough jetting/descaling, and choosing the right fix: patch (1–3 m), full-length lining (up to 30 m), or excavation for collapses and sags. Always pressure/CCTV test, document with photos, and communicate clearly to prevent callbacks and disputes.

Table of Contents

• Introduction
• Key Takeaways
• Drain Repair Diagnosis: From CCTV to Plan
• Jetting and Cutting: Preparing the Pipe for Repair
• No-Dig Drain Repair Methods That Last
• Open-Cut Drain Repair: When You Have to Dig
• Quality Control, Testing, and Sign-Off
• Pricing, Proposals, and Reducing Admin
• FAQ
• Conclusion

Key Takeaways

• A proper CCTV survey after jetting saves 1–2 return visits by revealing the true defect length and location.
• Patch repairs shine for 1–3 m defects; full-length lining works best on 10–30 m runs with multiple cracks and joints.
• Dig only when you’ve got collapse, severe deformation, or sags; plan for 0.6–1.2 m typical domestic depths and safe shoring.
• Test every repair: water/air test plus a post-works CCTV. Keep photos and notes to prevent disputes.
• Tighten your admin: proposals in minutes with photos and voice notes, e-sign in hours, invoice on acceptance.

Drain Repair Diagnosis: From CCTV to Plan

Many contractors struggle because the first CCTV survey is done on a dirty pipe. Debris hides the real problem. The fix? Clean first, film second.

Symptoms and Root Causes

• Slow drains and gurgling: often heavy scale, fat build-up, or partial root ingress.
• Repeated blockages: displaced joints in old clay, 100 mm (4-inch) pipes with root-regrowth, or a slight belly.
• Foul smells: cracked sections, open joints, or orphaned connections.

CCTV Survey That Tells the Truth

• Jet the line: clear to bare pipe if possible.
• Camera best practice: centre the lens, record chainage every 0.1 m, call out material (clay/PVC/concrete), diameter (100/150 mm), and defects (crack, displaced joint, intrusion, deformation).
• Mark it up: spray-mark on the surface and log depth at key defects with a sonde; note distances at 5 m intervals for reference.

Turn the Survey Into a Repair Plan

• Single defect 0.5–2.0 m: consider a patch repair with 100–150 mm overlap each side of the defect.
• Multiple joints and longitudinal cracking over 10–30 m: full-length CIPP lining.
• Deformation, collapse, or a water-holding belly: excavation and replacement.

Real-world note: That bungalow with a 40-year clay line under the ash tree? Expect 2–3 displaced joints between 6–12 m and root ingress at the collar. Lining beats chasing patches there.

Jetting and Cutting: Preparing the Pipe for Repair

You can’t line or patch over scale and roots and expect it to hold. Prep is everything.

High-Pressure Jetting

• Use 100–200 bar (typical) with appropriate nozzles; start low, increase as needed to avoid blow-back.
• Pull back slowly to scour evenly; spend extra time at 45-degree bends.
• In kitchen lines, hot-water jetting helps with FOG (fat, oil, grease) build-up.

Mechanical Descaling and Root Cutting

• Chain flails or Picote-style tooling to remove hard scale in 100 mm and 150 mm lines.
• Root cutting head followed by a rinse; avoid over-cutting at joints to prevent further displacement.
• Re-survey immediately after: you want clean visuals before deciding on the repair.

Example outcome: A 15 m 100 mm clay run often cleans in 30–60 minutes including re-survey, saving hours compared to discovering surprises mid-repair.

No-Dig Drain Repair Methods That Last

No-dig drain repair reduces disruption, especially under driveways, extensions, or landscaping. Pick the right method for the defect length and pipe condition.

Patch Repair (1–3 m Sections)

• Best for single cracks, minor displaced joints, or isolated root entry.
• Steps:
  1. Prep: clean and dry the section; measure defect length plus 100–150 mm overlap either end.
  2. Impregnate: wet-out fibreglass mat or silicate felt patch per manufacturer ratios.
  3. Position: use a packer to the exact chainage; centre over the defect.
  4. Inflate and cure: hold pressure for the stated cure time (often 45–90 minutes ambient; faster with hot water/steam).
  5. Deflate, remove, and CCTV: confirm smooth finish and full coverage.
• Common mistake: under-sizing the patch length, leading to edge leaks. Always overlap.

Full-Length CIPP Lining (10–30 m Runs)

• Ideal for multiple defects, longitudinal cracking, and older clay with weak collars.
• Steps:
  1. Survey and measure: calculate exact length, diameter (100/150 mm), and number of bends.
  2. Bypass plan: keep fixtures live if needed using temporary diversion.
  3. Wet-out: ensure even resin saturation. Watch ambient cure windows; hot-water or steam reduces cure to 1–2 hours.
  4. Inversion/drag-in: maintain a steady inversion pressure; protect liner nose through bends.
  5. Cure and cool: don’t rush the cool-down; it prevents post-cure shrink and wrinkles.
  6. Reinstatements: robotic cutter for lateral reinstatement if required; confirm with CCTV.
• Watch-outs: Sharp bends and diameter changes need compatible liners; excessive sags defeat lining.

When No-Dig Won’t Work

• Collapsed pipes, severe deformation, or bellies holding water over 1–2 m.
• Section missing, crushed by traffic load or tree root mass.
• Access impossible due to tight traps or lack of launch manholes.

Method Comparison

Open-Cut Drain Repair: When You Have to Dig

Sometimes you’ve got to open the ground. Do it once, do it right, and make it safe.

Locate and Expose Safely

• Pre-dig checks: use a cable avoidance tool and signal generator (CAT & Genny), consult LinesearchBeforeUdig, and follow HSG47 for underground services.
• Support: for depths around 0.6–1.2 m (typical domestic), use trench boxes or shoring as needed; step-in sides in suitable soils.
• Access: plan spoil storage and site access to protect paving and prevent collapse.

Replace the Section

• Cut back to sound pipe: at least 150–300 mm each side of the defect.
• Use flexible couplers rated for 100/150 mm transitions; prep ends clean and square.
• Bedding: 10–20 mm pea gravel or approved granular material, 100–150 mm under and around the pipe.
• Gradient: aim for a steady fall; typical foul lines run around 1:40 to 1:80 depending on diameter and local regs.

Testing and Reinstatement

• Test before backfill: water test with a head of water or low-pressure air test as per local regs; CCTV from access to access.
• Backfill in 150 mm lifts, compact each layer; reinstate surfaces to match (flags, tarmac, concrete) with proper sub-base.

Real scenario: A 2 m belly under a block-paved drive. Dig and replace just the affected 2.5–3.0 m, reinstate blocks like-for-like, and prove with CCTV to avoid arguments later.

Quality Control, Testing, and Sign-Off

The best drain repair still fails if you skip testing. Build QC into your method.

Test Methods That Stick

• Water test: hold a head of water for 5–10 minutes and observe. Top up if required; check joints.
• Air test: where allowed, a controlled low-pressure test with a manometer. Follow local guidance (e.g., Building Regulations Part H in the UK).
• CCTV post-works: record from nearest upstream access to downstream outlet, call out chainage and reinstatements.

Documentation That Prevents Disputes

• Photos: before, during, after; include measurements and chainage markers.
• Drawings: simple sketch with distances (e.g., 12.6 m to patch centre at 100 mm depth).
• Warranty: state scope clearly—e.g., “Patch from 10.8–12.8 m on 100 mm clay; excludes upstream defects.”

Many contractors find that a solid post-works pack cuts back-and-forth by half because everyone can see what was done and tested.

Pricing, Proposals, and Reducing Admin

Pricing drain repair is about time, risk, and disruption. Communicate that clearly and win the job faster.

Estimating the Job

• Jetting/Descale: allow 30–90 minutes per 15 m run depending on condition.
• Patch: 2–3 hours including setup, cure, and CCTV.
• Lining: 1 day for 10–20 m single-run lining with reinstatements; add time for multiple junctions.
• Dig and Replace: 1 day per 2–4 m section at 0.6–1.2 m depth, plus reinstatement.
• Add contingencies for wet ground, traffic management (Chapter 8 on the highway), or weekend working.

Win the Job Faster With Clear Proposals

• Show options: quote good/better/best—e.g., “Patch one section”, “Full lining of 15 m”, “Excavate and replace 3 m.”
• Spell out testing and warranty. Include access needs and making-good scope.
• Use photos and chainage notes to prove the need and educate the client.

Use Donizo to Cut Admin Time

• Capture site notes fast with Voice to Proposal—speak your findings, attach CCTV stills, and generate a professional proposal in minutes.
• Send branded PDF proposals by email; clients review everything in a portal and accept via e-signature. Many contractors report acceptance within hours when it’s this simple.
• Convert to invoice with one click once signed. On Ascension, add your logo and track payments; on Autopilot, use advanced templates and a margin estimator to price confidently.
• If you’re just testing the waters, the Discover plan lets you create unlimited proposals and collect e-signatures, with PDF export available.

Internal link ideas: see [learn more about invoicing] and [creating drain survey reports that sell] to build out your process.

FAQ

What’s the best drain repair for a cracked pipe without digging?

For isolated cracks or a single displaced joint over 1–3 m, a no-dig patch repair is usually the best drain repair. Clean and descale first, then centre a patch with 100–150 mm overlap beyond the defect. Cure properly and verify with a post-works CCTV. For multiple defects, consider full-length lining.

How long does a typical drain repair take?

A standard patch repair often takes 2–3 hours end-to-end, including prep and cure. Full-length lining on a 10–20 m run is usually a one-day job, assuming good access and no complex junctions. Dig-and-replace sections of 2–4 m at 0.6–1.2 m depth typically run to a day plus reinstatement time.

Can you line a drain with bends and diameter changes?

Yes, many liners handle multiple 45-degree bends and slight diameter changes. The key is choosing a liner and resin system rated for those conditions and managing inversion pressure and cure time. Sharp bends, significant diameter shifts, or sags may require sectional lining, careful planning, or excavation.

When should you choose excavation over lining?

Excavate when there’s collapse, severe deformation, missing sections, or a belly that holds water for 1–2 m or more. Lining relies on a stable host pipe and won’t fix poor gradients. If in doubt, jet, resurvey, and decide based on clean visuals and measured depths.

How do you price a drain repair job fairly?

Price by method, time, access, and risk. Allow for jetting/descale time, patch vs lining vs excavation durations, reinstatement, and testing. Show options (e.g., patch vs lining), include photos and chainage, and define warranty scope. Tools like Donizo’s margin estimator on Autopilot help set profitable prices confidently.

Conclusion

Durable drain repair is all about sequence: clean, diagnose, pick the right method, and prove the result. Use patches for 1–3 m defects, line 10–30 m runs with multiple issues, and dig for collapses or bellies. Test every time, document everything, and communicate clearly. Want to reduce admin? Use Donizo’s Voice to Proposal to build a photo-rich proposal in minutes, send for e-signature, and convert to invoice when accepted. Try the Discover plan to streamline proposals today, and step up to Ascension or Autopilot when you want branding, payment tracking, and advanced templates.