Sagging, fracture or crack: what is the difference
Sagging occurs when the ground beneath the pipe settles. In many parts of the Netherlands, with soft clay and peat soils, this is a familiar phenomenon. The pipe dips locally and the fall disappears, so water and debris stay standing at that spot. On CCTV footage you see this as a waterline that keeps rising. The longer it stays that way, the more silt builds up there and the more often the pipe blocks.
A fracture is a pipe that has broken into pieces in one or more places. This happens more often with old clay or concrete pipes under driveways or under heavy traffic. Cracking is a lighter form: the pipe is still whole but shows longitudinal or circumferential cracks. Loose or displaced joints also fall into this category, because they let in groundwater and roots. Even a crack that is small now can grow as the ground settles further.
Patch repair or replacing the sewer pipe
A patch repair is a short liner, often half a metre to a few metres long, placed over the damage from the inside. It is a quick, tidy solution for a single crack, a leaking joint or local root ingress, as long as the pipe is still in line. No digging is needed and the pipe is fully usable again after a few hours. The CCTV footage determines whether a patch repair is enough or whether more is needed.
- Patch repair: one or a few local cracks or leaking joints
- Relining: several defects spread over a longer run
- Local replacement: sagging with a backfall or a broken section of pipe
- Full replacement: a pipe that has sagged, broken or badly deformed along its whole length
For replacement, the engineer usually chooses PVC, with the correct transition to the existing material. The fall is restored too, so the water can flow freely to the boundary chamber or the main sewer again. After the trench is backfilled, paving or garden is restored as well as possible. If the pipe runs under a floor, the engineer first checks whether relining is possible, so nothing inside the house needs breaking out.
Who is responsible for the repair
In most municipalities your own responsibility runs up to the property boundary, often marked by a boundary chamber or inspection chamber. The section beyond that, towards the main sewer, is usually the municipality's. The rules vary by municipality, so it is wise to check before any work is done on the public section. Bosmans carries out work on the section you are responsible for yourself.
Bosmans helps you get this clear. The CCTV footage shows exactly where the damage is, which is useful if you contact the municipality or your insurer. With rented homes and apartments, the landlord or owners' association often decides who commissions the work. In that case too, Bosmans supplies a clear report with footage. That way everyone has the same information and the repair can be scheduled quickly.