A question for storm season
Water came into the basement during a storm. What do we do first?
Water in the basement after rain calls for safety before buckets: stay out until you know the power is off, get out if you smell gas, then find the source and start drying within a day or two.
Maryland Basement Questions
A column that answers the questions Maryland homeowners keep asking about the plumbing below the first floor, one question at a time, with the sources shown.
How this column works
Every page here takes one question that comes up again and again in basements across Montgomery, Prince George's, Frederick, Howard, Anne Arundel and Baltimore County. Why does the sump pump keep running? Who pulls the permit for a basement bathroom? What do you do when the floor drain backs up?
The questions are the common ones, not letters from particular readers. Each answer is built from what the people who set the rules actually publish: WSSC Water, county permit offices, the EPA, CDC and FEMA, and the manuals from the companies that make the pumps, valves and heaters. Those sources are linked on every page, so you can read them yourself.
A few things this site is not. It is not a plumbing company. Nobody here installs or repairs anything, and there is no phone line to call. If water is rising near live wiring, you smell gas, or sewage is coming in fast, call 911 or your utility first and read later.
Pick a question below, or browse by the kind of trouble you have.
From the mailbag
My sump pump runs every few minutes even when it hasn't rained. Is that normal?
A sump pump running constantly in dry weather is sometimes just groundwater still draining, but a cycle every few minutes usually means a stuck float, a failed check valve, or a pit or pump that's the wrong size.
Something's backing up or smells
Why is sewage coming up through our basement floor drain?
Sewage backing up through a basement floor drain means wastewater can't get out of the house: either your own sewer line is blocked, or the public sewer is overloaded and pushing back. The floor drain is simply the lowest opening.
What's the difference between an ejector pump and a sump pump?
Ejector pump vs sump pump comes down to what's in the pit. An ejector lifts toilet and drain waste up into the sewer; a sump pump sends clean groundwater outside.
A pipe in the basement froze. How do we thaw it safely?
To thaw frozen pipes safely, open the nearest cold faucet, then warm the pipe slowly with a hair dryer, heating pad or hot towels until full pressure comes back. Never use an open flame of any kind.
It's the water heater (or the corner it sits in)
Does our basement water heater need a drain pan?
A water heater drain pan isn't required by code in a WSSC-area basement, but it's still a good idea. Outside Montgomery and Prince George's, check your county, because the model code asks for one wherever a leak would do damage.
Who issues plumbing permits where we live: WSSC Water or the county?
A WSSC plumbing permit is what you need in Montgomery and Prince George's counties. Everywhere else in the area, including Baltimore City, the county or city permit office issues it.
How do I know what size sump pump our basement needs?
What size sump pump you need comes down to two numbers, not horsepower: how many gallons per minute flow into your pit, and the total head the pump has to push that water against.
Something's backing up or smells
Our basement floor drain smells like sewer. What's wrong with it?
A floor drain that smells like sewer usually has a dry trap: the small pool of water that blocks sewer gas has evaporated. Pour in a bucket of water. If the smell returns quickly, something else is going on.
Can we put a bathroom in a basement that sits below the sewer line?
Yes, a basement bathroom below the sewer line is doable. The waste just has to be pumped up, from a sealed ejector basin in the slab or an upflush macerating unit, installed by a licensed plumber with a permit.
At what temperature do pipes freeze in a basement or crawlspace?
There's no single pipes-freezing temperature to watch on the weather app. Risk depends on how cold the air around the pipe gets, how long it stays that cold, and whether drafts or missing insulation let winter reach it.
It's the water heater (or the corner it sits in)
Why did the plumber say we need an expansion tank?
A water heater expansion tank gives heated water room to grow. When a check valve, backflow preventer or pressure-reducing valve stops water flowing back to the street, the code calls for expansion control, usually a tank.
Does homeowners insurance cover a sewer backup or a failed sump pump?
Sewer backup insurance usually isn't part of a standard Maryland homeowners policy. A backup or a sump pump that quits is generally covered only if you added a water/sewer back-up endorsement.
More questions
- Is a battery backup sump pump worth it?
- Sewage backed up into the basement. How do we clean up safely?
- Is an upflush toilet a good idea for our basement?
- Our outside faucet froze and now it leaks inside the wall. What happened?
- The water heater is leaking from the bottom. Is it done?
- Is there county help paying for a backwater valve or other flood fixes?
- Could a water-powered backup sump pump work on our public water?
- Should we get a backwater valve, and who can put one in?
- The alarm on our ejector pump is going off. What now?
- How do we keep crawlspace pipes from freezing?
- Our gas water heater sat in floodwater. Can we just relight it?
- How do we check that a plumber is licensed in Maryland?
- Where is our sump pump allowed to send the water?
- Why does the floor drain overflow when the washing machine drains?
- Why does the basement bathroom smell even though it's clean?
- We're going away in January. What should we do with the water?
- How old is too old for a basement water heater?
- What should we check in the basement before we buy a house?
- How long should a sump pump last, and when do we replace it?
- When sewage backs up, is it our problem or the utility's?
- Do we need a permit to add a basement bathroom in Maryland?
- Where can a water softener drain in a finished basement?
- Why is there water on the basement floor when the sump pit is dry?
- Why do the basement drains gurgle when someone flushes upstairs?
- Where should the dehumidifier and AC condensate drain in the basement?
- How fast does mold start after a basement leak?
Browse by question type
- 9There's water on the floorSump pumps, storms, groundwater and the damp that follows
- 7Something's backing up or smellsFloor drains, traps, sewer backups and backwater valves
- 6We want a bathroom down thereEjector pumps, upflush toilets, below-sewer fixtures and permits
- 5It frozeFrozen pipes, crawlspaces, outside faucets and winter trips
- 7It's the water heater (or the corner it sits in)Water heaters, pans, expansion tanks, softener and condensate drains
- 5Rules, money and who to callWSSC and county permits, insurance, rebates and hiring