District of Columbia · Washington–Arlington–Alexandria metro
Plumbing help in Washington, DC, DC
Older PipesFrozen Pipes
Washington, DC's rowhouses and older apartment buildings mean long-serving pipe, shared stacks and, in many older homes, lead service lines. The District writes its own plumbing code and licenses its own plumbers, and its Potomac-sourced water is moderately hard.
- Median home built
- 1960
- Built before 1980
- 66%
- Owner-occupied
- 41%
- Water hardness
- Moderately hard
- ≈ 6 grains/gal
- Winter
- Regular hard freezes
- Plumbing code
- IPC
The plumbing calls that come up most in Washington, DC
- Water Line Repair
Older rowhouses may still have lead service lines; DC Water runs replacement programs.
- Drain Cleaning
Old cast iron stacks in rowhouses and apartments narrow with buildup.
- Sewer Backup
Heavy storms can surcharge older combined sewers into basements.
Emergency plumbing in Washington, DC
Call (833) 878-1592Shut off your main water supply if it's safe to do so. The emergencies below are listed most likely first for Washington, DC homes, based on local conditions.
What's behind the walls of Washington, DC's older homes
The median home in Washington, DC was built in 1960, and 66% of homes predate 1980. Homes from that era were typically built with copper or galvanized supply, cast iron drains, clay or cast iron sewer laterals.
- Galvanized steel supply (1900–1960)
- Copper supply (1950–2000)
- Polybutylene (some homes) (1978–1996)
- PEX / CPVC (1995–today)
Frozen pipe risk in Washington, DC
Regular hard freezes · 66% of Washington, DC homes were built before 1980
Plumbing code and permits in Washington, DC
The District of Columbia Plumbing Code (2017) is the 2015 International Plumbing Code as amended by DC, and plumbers are licensed by the Board of Industrial Trades. [2]
Washington, DC's water: moderately hard
DC Water reports tap water hardness typically around 70 to 120 ppm (3 to 9 grains per gallon), peaking in warmer months. [1]
Plumbing services for Washington, DC homes
Washington, DC plumbing questions
Is DC tap water hard?
Moderately. DC Water reports about 70 to 120 ppm (3 to 9 grains per gallon), higher in summer.
Does my DC home have a lead service line?
Older homes may. DC Water has an online service line map and replacement programs; check your address before hiring a plumber.
Which plumbing code applies in DC?
The 2017 District of Columbia Plumbing Code, based on the 2015 International Plumbing Code with DC amendments.
How do I check a DC plumber?
Verify the license with the DC Department of Licensing and Consumer Protection (Board of Industrial Trades).
Why do DC basements flood in storms?
Parts of DC have older combined sewers that can surcharge in heavy rain. A backwater valve and a camera inspection of the lateral are common fixes.
Sources (3)
- U.S. Census Bureau, ACS 2024 1-year (B25035) · checked 2026-10-01
- DC Water, How hard is the water in the District of Columbia? · checked 2026-10-01
- DC Department of Buildings, 2017 DC Construction Codes · checked 2026-10-01