Recently we inspected a large group of sewer lines in Chesapeake, VA. Our pipe inspections revealed dozens of lines becoming backed up due to offset pipes.
If your property is plagued with sewage backups, offset pipes can cause aging plumbing infrastructure or foundations to shift drain pipes. Sewer mains and lateral lines can slowly become offset over time. Offset pipes and drains often do not cause immediate problems unless it is being caused by a collapsing of the piping infrastructure.
Reasons why your sewer lines may become offset are:
- Small leaks causing ground to washout underneath the lines
- Shifting foundations
- Ground settling
- Trees and roots pushing on a pipe or worst case causing root infiltration
Washout- if a pipe has a constant leak the ground below the pipe will wash out and cause the pipe to be subject to pressure from gravity. Older pipes, especially deteriorating lines can break or become offset causing debris and dirt to buildup and eventually become clogged.
Shifting Foundations- over time structures will settle and move causing pipes to be subject to massive amounts of pressure. This external pressure on a pipe will cause the lines to break or become offset.
Ground Settling- settling grounds, especially in sandy areas can cause major problems. The same as shifting foundation problems, this can cause a sewer line to become subject to exterior pressure and become offset and damaged.
Trees- trees are a very powerful and slow moving threat to sewer lines. As you can imagine from visible damage to parking lots and sidewalks you have seen in the past, the same thing is happening all the time underground.
Tree roots can travel great distances in search of water sources.
Underground sewer lines are often draining warmer water through them causing condensation to occur on the outside of a pipe line. This will naturally attract trees to sewer lines and cause constant damage over time.
Improper Installation- some times we come across lines that have been improperly installed. Some times especially when large crews are doing massive pipe and sewer line installations a few connections will be neglected and backfilled without being properly connected.
Identifying offset sewer pipes
The best way to identify an offset sewer line or any offset pipe is with a cctv camera inspection. Electrical conduit, sewer lines, main lines and other pipes can be subject to becoming offset over time.
Fixing offset sewer lines
Offset drain lines can be cured usually with a small amount of excavation to access the damaged pipe. Sometimes the offset will cause the structural integrity of a pipe to be compromised and replacing the entire line may be necessary.
The cause and location of an offset line will determine the necessary steps to cure a pipe.
CIPP or cured in place piping can fix a sewer line if the offset is not major. The liner installation will adjust to the natural flow of the offset pipe and create a smooth path to restore the proper flow.
Since cured in place piping installations are usually done in one long seamless and jointless application this will increase the flow and eliminate the threat of leaks due to any pinholes or cracks that are causing problems.
Offset pipes are a silent but deadly problem for plumbing infrastructures.
Since it is mostly underground or encased in concrete slabs or inside of walls for roof drains it is difficult to prevent this problem. Also, since the problem does not cause immediate damage the problem can occur for long periods of time until a system fails completely.
Preventing Offset Drains and Sewer Lines
The only way to ensure that your systems are correct is to stay on top of drain lines and get a cctv pipe inspection for your properties done before you plan to occupy a property and every so often there after.