Seattle and Tacoma, WA
Sewer line replacement cost in Seattle and Tacoma
627,187 homes across King County, Pierce County, Snohomish County were built before 1975, about 37% of the housing stock. Those are the homes on cast iron, clay, concrete, and Orangeburg lines that fail.
Why sewer lines fail here
Soil. Glacial till and wet clay on hillsides, with heavy winter rain that saturates the ground and drives root growth into any crack.
What's in the ground. Concrete and clay side sewers in most pre-1970 homes, Orangeburg in a share of 1940s to 1960s houses, and cast iron near the foundation.
Home sales. A sewer scope is standard practice in a Seattle area home purchase. Most buyer agents order one on any home built before 1980.
Insurance. The side sewer from the house to the main is the homeowner's responsibility in Seattle, Tacoma, and most King County cities, and standard policies do not cover it.
Specialist availability in Seattle and Tacoma is not confirmed yet. You can still get a free explanation of your report, and you can request local help so we can tell you if a participating specialist becomes available.
Pre-1975 housing by county
Cities in Seattle and Tacoma
Common questions
How much does sewer line replacement cost in Seattle and Tacoma?
Most full replacements in Seattle and Tacoma land between $6,000 to $15,000 for trenchless lining and $5,000 to $25,000 for dig-and-replace, depending on length, depth, and what the line runs under. Spot repairs run $1,500 to $4,500.
Why do sewer lines fail in Seattle and Tacoma?
Glacial till and wet clay on hillsides, with heavy winter rain that saturates the ground and drives root growth into any crack.
What kind of pipe is under homes in Seattle and Tacoma?
Concrete and clay side sewers in most pre-1970 homes, Orangeburg in a share of 1940s to 1960s houses, and cast iron near the foundation.
Do buyers get sewer inspections in Seattle and Tacoma?
A sewer scope is standard practice in a Seattle area home purchase. Most buyer agents order one on any home built before 1980.
Will my insurance pay for it?
The side sewer from the house to the main is the homeowner's responsibility in Seattle, Tacoma, and most King County cities, and standard policies do not cover it.