Looking for a cast iron pipe plumber in Washington, DC? Describe your project once and up to three licensed plumbers who work in Washington and District of Columbia get back to you with a quote. It's free and there is no obligation.
Washington is home to about 702,250 people (2024 Census Bureau estimate), a growing community (+1.8% since 2020). With 11,489 people per sq mi, it is a densely built-up area. Homes built before the mid-1970s often still have cast iron drains reaching the end of their life.
Washington at a glance
- Population (Census Bureau estimate, 2024)
- 702,250 (+1.8% since 2020)
- Rank in District of Columbia
- 1st of 1 cities and towns
- Land area
- 61 sq mi
- Population density
- 11,489 people per sq mi (densely built-up)
- Type
- City (Washington city)
- Main county
- District of Columbia
What to check before hiring in Washington
- Camera first: a video inspection shows where and how badly the pipe is damaged.
- License and permit: in District of Columbia, drain work is done by a licensed plumber under a permit.
- Method: ask for both lining and replacement options when possible.
- Price drivers: length, slab access, tunneling, method and restoration.
Useful official resources
-
IAPMO: plumbing codes
Official information and guidance.
-
NASSCO: pipeline rehabilitation
Official information and guidance.
Services available in Washington
-
Cast iron drain replacement
Replacement of cast iron drain lines with PVC, including under-slab work where needed.
-
Cast iron pipe lining
Rehabilitation of cast iron drains with an epoxy or cured-in-place liner.
Frequently asked questions in Washington
How much does cast iron replacement cost in Washington, DC?
It depends on the length, the slab and the method. Describe your home: plumbers who serve Washington reply with a quote.
How long does it take?
From a few days for lining to a week or more with tunneling.
Can I stay at home?
Often yes, with limited plumbing use during the work.
Which licensed plumbers will contact me?
Up to three independent licensed plumbers who serve Washington and the surrounding area, chosen for the service you need. Your details are shared only with your consent.
Source: U.S. Census Bureau, Population Estimates Program (Vintage 2024) and Gazetteer Files (public domain), imported on 10/31/2026. Figures describe the incorporated place or county as published; they are shown for information only.