Plumbing in Baltimore is the stack inside a long rowhouse, with fixtures stacked floor over floor. Galvanized supply lines still feed plenty of kitchens and baths. Cast iron still carries the waste. A leak in the ceiling of the kitchen is frequently the bath above it, and sometimes it is the roof pretending to be a pipe. Say which you suspect and why.
Find the main shutoff, often in the cellar, before you need it in a hurry. Old valves seize. Outdoor spigots on the alley wall freeze in a cold snap if the inside valve was never closed. Basement floor drains and sump pits matter when a hard rain runs down the alley and finds the low house. If water is coming up from a drain rather than down from a fixture, say that clearly. It is a different emergency from a burst supply line over the stair.
Water heaters in these houses live in closets, cellars, and sometimes awkward corners under a stair. Say gas or electric, and whether the tank leaked or went cold. A relief line dripping onto a dirt cellar floor can be ignored for too long. Slow drains in a kitchen that shares a line with a bath often mean a clog in a branch, not a failure of the whole sewer, but roots and a settled lateral under an old street are common enough to mention if several fixtures gurgle together.
Remodels that added a powder room or a basement bath may have a pump you need to describe. Original houses did not always plan for a fixture below the street line. If the alley cleanout is buried or the only access is inside a finished cellar, say so. You do not need every pipe material named. You need the wet spot, the floor, and whether more than one fixture is involved. Shared-wall noise from a neighbor running water is not, by itself, your leak.
Describe what is wet and whether you can shut the water off. Plumbing in Baltimore is old metal in narrow chases, alley walls that freeze, and cellars that take storm water. A top-floor sink and a basement drain are both this call if you say which one. Call the number on this page.