Baltimore Rowhouse Plumbing: How the Lines Run and How Leaks Reach Next Door

Where does rowhouse plumbing fail first?

Check four places first: old galvanized water pipe, old cast iron drains, pipes along outside walls, and the main drain that carries everything to the sewer. Each shows up in HUD, Baltimore City DPW or City plumbing code guidance, and in a row home a leak at any of them sits beside a wall your neighbor shares.

• Galvanized water pipe. HUD’s rehab inspection guideline gives galvanized steel a service life of 20 to 50 years and names rust-colored water, especially from hot lines, and low water pressure as signs of trouble. It warns that galvanized joined to copper or brass without a dielectric coupling can corrode, and advises considering replacement whenever galvanized pipe is exposed; see replacing galvanized supply lines in an older rowhouse.
• Cast iron drains and stacks. HUD lists cast iron waste pipe at 75 to 100 years in a table built largely from industry estimates, and at 75 years in its capital needs tool. Leaks, slow or clogged drains and sewer odors are the signs HUD gives that a drain, waste and vent system needs work. The warning signs of a failing cast iron drain are covered in detail separately.
• Pipes along outside walls. Baltimore City DPW says most water meters and pipes sit in places without heat, like basements or outside walls, and the City plumbing code requires pipes in exterior walls to be protected from freezing. The Institute for Business & Home Safety adds that cracks in an outside wall leave pipes vulnerable to freezing even above 20°F. Before winter, work through the steps for keeping pipes along outside walls from freezing.
• The main building drain and sewer lateral. HUD says a backup at the lowest fixture while several fixtures drain points to a clogged or failing main drain between the house and the public sewer, most often from tree roots. In Baltimore City the owner is responsible for the lateral up to the property line; see repair of a row home’s private sewer lateral.
• Gutters shared by the row. A wet party wall is not always a pipe. Baltimore’s preservation commission (CHAP) warns that heavy rain can overwhelm gutters on rowhouses that have one gutter for an entire roof and back water up under flat roof membranes.

What to do when water comes through a shared wall

Find which side the water starts on, stop it if it is yours, tell the neighbor if it is not, and document everything before cleanup. Water inside a wall can do damage long before it shows: writing about roof leaks, CHAP notes that damage to concealed roof and wall structures may go unnoticed for years.

1. Check your own lines along that wall. Look at supply pipes, fixtures and the drain stack on the floors above the stain. If it spreads during heavy rain rather than when water runs, look at the roof and gutters.
2. If the leak is yours, close the main valve. Use the valve where the water line enters the basement. The first steps after a pipe bursts cover electricity, water heaters and drying out.
3. If it is coming from next door, tell the neighbor right away. If the house is a rental, Baltimore City DHCD says the owner is responsible for repairing defective and damaged items, and the owner of record can be found through the State Department of Assessments and Taxation. For a vacant house or an owner you cannot reach, DHCD says to dial 311 about a property causing problems in your neighborhood.
4. Document the damage. NAIC advises photos or video of the damaged areas and belongings, plus notes. The Maryland Insurance Administration (MIA) says to let an adjuster or agent see damaged property before you remove it.
5. Call your insurer promptly. MIA warns that delaying a claim or failing to protect the property from further damage can put coverage at risk. Make only the repairs needed to stop further damage until you have talked to the insurer, and keep every receipt.
6. Dry the area within 24 to 48 hours. EPA gives that window to prevent mold. Philadelphia’s rowhouse manual notes that floor joists typically rest in pockets in the party walls and that water penetration can erode that joist-to-masonry connection.

Renting a Baltimore rowhouse: who fixes the plumbing?

In Baltimore City the owner must keep the plumbing in repair, and a tenant who controls the heat must keep the home warm enough to protect the pipes. The City’s Property Maintenance Code makes each owner and operator responsible for maintenance and requires plumbing defects, including deterioration and damage, to be corrected.

• Owner: repairs or replaces defective and damaged items in every unit, according to DHCD, and is responsible for any insanitary condition caused by a sewer back-up or a structural defect.
• Tenant: keeps the unit clean and sanitary, which DHCD says includes keeping plumbing fixtures free of anything that could clog them, keeps the unit warm enough to prevent damage to the plumbing when the tenant controls the heat, and lets the owner in at reasonable times for repairs. DHCD notes an owner may hold a tenant accountable for interior damage caused by negligence.

When a landlord does not fix a serious problem, Baltimore City’s rent escrow law, Public Local Laws § 9-9, lets a tenant go to District Court and pay rent into court. It covers conditions that are a serious threat to life, health or safety, such as a lack of hot or cold running water or of adequate sewage disposal, and says it is not meant for minor code violations. The landlord must first have notice, such as a certified letter or a government violation notice; more than 30 days to make the repair after notice is presumed unreasonable, and the landlord has a defense if the tenant caused the condition or unreasonably refused entry for repairs. Maryland’s statewide law, Real Property § 8-211, lists the same kinds of conditions and applies throughout the State, including Baltimore County.