A sewer scope is not required on new construction, but it is often worth doing before possession or well before the new-home warranty coverage for plumbing ends. New laterals can hold construction debris, sag where trench backfill settles, deflect or crack under compaction equipment, or be poorly joined to the municipal service stub. Finding these while the builder is still responsible costs far less than finding them later.
- New does not mean inspected: the plumbing inspection happens before backfill, and a lot can happen to a pipe after it is buried.
- Construction debris and sags from settling backfill are the two most common findings in new laterals.
- Scope before your warranty coverage for delivery and distribution systems ends, and after the first spring thaw if you can.
- Municipal inspection of new subdivision mains usually covers the public side, not the private pipe from the stub to your house.
- Report anything found in writing, with the dated video, inside the warranty period.
01 /What goes wrong in a brand-new sewer line?
A brand-new sewer line most often goes wrong through what happens around it during construction rather than through the pipe itself. Plastic sewer pipe is durable when it is bedded, joined and backfilled correctly. The problems come from rushed trenching, backfill that settles, heavy equipment passing over a shallow pipe, and trades washing materials down the nearest drain.
| Defect | How it usually happens | What the camera shows |
|---|---|---|
| Construction debris | Concrete slurry, drywall mud, grout, tile adhesive and offcuts washed or dropped into drains | Hardened lumps in the invert, debris caught at joints or in a low spot |
| Sag or belly | Bedding not compacted, or backfill placed wet or frozen that settles after the first thaw | Water deepening over a stretch; the lens going under, then climbing out |
| Deflected or oval pipe | Poor side support, or heavy loads over a shallow pipe | The circle flattening; tight clearance for the camera head |
| Joint not fully seated | Spigot not pushed home or gasket rolled during assembly | A gap at the bell, a displaced gasket, or water seeping at a joint |
| Cracked pipe or fitting | Excavator bucket, rock in the backfill, compaction equipment | A crack line or broken bell, sometimes with soil visible |
| Misaligned connection to the stub | Lateral joined to the service stub at the property line with an offset or wrong fitting | A step, a lip or a sudden change in grade at the coupling |
| Shear at the foundation wall | House and backfill settle differently where the pipe exits | An offset or crack right outside the foundation |
None of these is exotic. Each is a known way for a new line to go wrong, and each is easier to settle with a builder than with a former owner. A sag in a new plastic lateral is the finding most worth documenting, because lining cannot fix grade and the usual repair is excavation.
02 /Doesn't the plumbing inspection already cover it?
The plumbing inspection covers the pipe at a point in time, usually before it is buried. New drainage piping is normally tested and inspected before it is covered, under the plumbing code as adopted in your province, and the inspector checks materials, grade and connections that are visible then. What the inspection cannot see is what happens afterwards: backfilling, compaction, landscaping, driveway pours and months of trades using the drains.
Many municipalities also camera-inspect new subdivision mains and service connections before taking them over from the developer. That work is about public infrastructure. It generally does not cover the private building sewer from the service stub to your foundation, and you will not usually see its results unless you ask. Treat it as reassurance about the street, not about your lateral.
03 /When should you scope a new home?
Scope a new home at the point where the result can still be acted on under warranty. For most buyers that means before or soon after possession, and again, if you want belt and braces, after the first spring thaw, when settled backfill has had a chance to show itself.
- Before possession, if the builder allows it
Ask whether a sewer scope can be done at or before the pre-delivery inspection. Some builders permit it; others ask you to wait until you own the house.
- Soon after possession
A first scope with the counter zeroed at the main cleanout gives you a baseline and catches debris while trades are still around.
- After the first spring thaw
Frozen or wet backfill placed in winter can settle as it thaws. A second look in late spring shows whether a belly has formed.
- Before driveway, deck or landscaping work over the route
Covering the lateral makes any later repair more expensive. See before you renovate.
- Before warranty coverage ends
Diarise the end date for plumbing systems on your warranty certificate and scope a few months before it, leaving time to file a claim.
04 /How does new home warranty affect a sewer defect?
New home warranty can make a sewer defect the builder's problem, but only inside the coverage periods and within the terms of your certificate. Most provinces run mandatory new-home warranty programs with tiered coverage: a shorter period for general labour and materials, a longer one for systems such as plumbing, and a longer one again for structure. In Alberta, for example, the legislated minimum coverage for delivery and distribution systems, which include plumbing, runs longer than the coverage for general labour and materials. Exact periods, exclusions and whether site services outside the foundation are included are set out in your warranty documents.
| Step | Why it matters |
|---|---|
| Read the certificate for what counts as plumbing and whether the building sewer outside the foundation is covered | Some programs treat site services differently from in-house systems |
| Keep the dated video, report and locate photos | Shows the defect existed inside the coverage period |
| Report in writing to the builder and the warranty provider | Verbal complaints are hard to prove later |
| Do not have the defect repaired first without talking to the warranty provider | Unauthorised repairs can complicate a claim |
| Ask for a post-repair video | Confirms the fix and restarts your baseline |
If you are buying a house that is only a few years old, ask whether warranty coverage remains and transfers to you. In many programs coverage follows the home for the rest of its term, which makes a scope before the plumbing coverage ends worth scheduling. The worth-it guide explains why timing is one of the three tests.
05 /What does a healthy new sewer look like on camera?
A healthy new sewer looks almost boring on camera: smooth, uniform plastic, joints every few metres showing as a thin ring at each bell, a thin and steady stream of water along the bottom, and no debris. Interior building drains are usually black ABS; exterior laterals are commonly green, white or cream PVC. The run should end at the service stub or the main with a clean, aligned connection.
Material changes are normal in some new builds: black ABS inside the house changing to green PVC outside the foundation is a planned transition, not a defect, provided the coupling is aligned. The pipe materials guide shows what each looks like.
06 /What should you ask the builder about the sewer?
Ask the builder who installed the lateral, whether and when it was inspected, where the cleanouts are, and how warranty claims on underground piping are handled. Put the questions in writing so the answers are on record.
- Was the building sewer inspected and tested before backfill, and can I have the permit final?
- Who installed the lateral from the foundation to the service stub: the plumber or a site-services contractor?
- Where are the interior and exterior cleanouts, and are any buried?
- When was the trench backfilled, and was it compacted in lifts?
- May I have a sewer camera inspection done before or at possession?
- How are warranty claims on underground piping handled, and by whom?
If the answers are vague, the scope becomes more valuable, not less. When you are ready, request an inspection quote and mention that the house is new and under warranty, so the operator records the details a claim will need.
FAQQuestions people ask
Do new houses need a sewer scope?
It is not required, but it is often worth it. New laterals can hold construction debris, sag where backfill settles or be poorly joined at the stub, and those defects are easiest to resolve while the builder's warranty applies.
Can a new sewer line have a belly?
Yes. A belly in a new line usually comes from poorly compacted bedding or backfill that settles after placement, especially fill placed wet or frozen. It shows as water deepening on camera.
Who pays to fix a sewer defect in a new home?
If the defect is covered by your new-home warranty and reported inside the coverage period, the builder or warranty provider is normally responsible. Coverage and exclusions depend on your certificate.
Is the city's service stub part of my new-home warranty?
Usually the municipal side belongs to the municipality, and the private lateral from the stub to your house is the owner's. Whether your warranty covers the private lateral depends on the program and certificate.
Should I scope before my one-year walk-through?
A scope before the end of your first year gives you time to raise any defect alongside other items, but check your certificate; plumbing coverage may run longer than the first year.
What debris is common in new sewer lines?
Concrete slurry, drywall compound, grout, tile adhesive, paint, gravel, rags and pipe offcuts. Hardened material can narrow the pipe and catch paper.
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