Sump Pumps, Basements and Crawl Spaces in Metro Atlanta

Is it rainwater, humidity or a plumbing leak?

Crawl spaces and basements get wet for three very different reasons, and the fix depends on which one you have. The best time to look is the day after a heavy storm, then again after a dry week.

That third row is easy to overlook. A dripping supply line, a cracked drain fitting or a water heater weeping into the crawl space can keep one area soaked indefinitely, and a pump would only hide it. Get help pinpointing the leak before buying any equipment.

Why Atlanta houses take on water

Lot shape matters: on a sloped lot, water that reaches the uphill side of a house has to go around or under it, and a yard that tilts toward the foundation sends every storm straight at the walls. Housing age plays a role too. About 42.7% of homes in the city of Atlanta were built before 1980, by Census survey figures, and older foundations were rarely built with the drainage details used today. Intown bungalows often sit on crawl spaces, while many suburban houses from later decades have full or partial basements dug into a slope.

Handle the outside first

The Department of Energy's Building America guidance for existing crawl spaces says to fix bulk water before anything else and warns that a sump pump alone may not solve the problem. Its outside checklist:

• Regrade soil so it slopes away from the foundation
• Repair or add gutters and downspouts so roof water lands well away from the walls
• Make sure patios, walks and driveways slope away, or add drains where they do not
• Where water still gets in, run drain pipe around the exterior footings to daylight or a drywell
• Seal crawl space vents and windows, and fill window wells above grade

Watching the house during a downpour is free and often revealing. A downspout dumping at a foundation corner, or a gutter overflowing above a basement wall, can explain most of the water you see underneath.

What a proper sump setup looks like

The same DOE guidance describes a plastic pit roughly 2 to 3 feet deep, set at the low point of the floor, with holes drilled in the bottom so it collects water from a rising water table before it spreads across the floor, and capped with a gasketed, tight-fitting lid. A submersible pump in the pit pushes water out through a discharge pipe.

Details that separate a good install from a weak one

• The pit sits at the true low spot, even if that is awkward to reach
• A check valve on the discharge keeps pumped water from falling back into the pit
• The pump has its own outlet, ideally on a circuit you can find in the dark
• The lid seals to the vapor barrier so the pit does not breathe humid air into the space
• A high-water alarm or battery backup is considered for storms that knock out power

Where the water goes matters as much as the pump. Send it into the yard far enough from the wall that it does not soak back in, and keep it off neighboring property. Do not tie it into a cleanout, laundry drain or floor drain: sanitary sewer lines are sized for wastewater, not rain. Plumbers who handle sump pump installation and repair can tell you whether you need a new pit or just a better pump in the old one.

Basements below the street: a second kind of backup

Not every wet basement is groundwater. If a floor drain or basement toilet sits below the level of the sewer main in the street, a blockage in the public line can push sewage up into the house. Hapeville's Water Department recommends a sewer backflow preventer on the lateral for buildings connected to the main at or below street level, and strongly encourages owners in at-risk areas to add one. That device belongs on the sewer line, not the sump discharge. If dirty water rises through a basement drain, a camera look at the lateral will show what is going on.

Keep the pump you have in working order

A pump that has sat idle through a dry stretch can fail on the first big storm. NDSU Extension engineers suggest a quick routine before the wet season:

1. Walk the discharge pipe outside and make sure it is clear and carries water away from the house.
2. Confirm the pump is plugged in.
3. Lift the lid and use a flashlight to look for debris near the intake.
4. Pour water in at about the rate it normally flows in, until the float starts the pump. Let it cycle on and off at least twice.
5. Test a battery backup the same way, and keep its battery maintained.

NDSU notes that a pump that sounds like it is moving gravel, or a float that is slow to respond, may need replacing, and that rusted motor bearings and poor float switch contact are common causes of failure. InterNACHI's life expectancy chart lists sump pumps at about 7 years, so an untested pump older than that deserves attention.

Repair the pump or replace it?

Many pump problems are not the motor at all. If nothing happens when the float rises, check the GFCI outlet and the breaker before anything else. A pump that hums but does not lower the water usually has debris against the intake or impeller. One that starts and stops in quick bursts may have a float set too tight, a basin that is too small, or a check valve letting the same water drain back again and again. If water rushes back down the pipe the moment the pump stops, the check valve is missing or stuck open. Those are all repairable. Grinding, rattling or a hot smell points to worn bearings or a failing motor, and at that stage most owners replace the pump rather than rebuild it.

Backup options

The storms that fill a pit are often the same ones that knock out power. A battery backup pump sits in the same pit and runs only when the main pump does not. A water-powered backup uses household water pressure instead of electricity, which means it connects to the drinking water supply, so ask the installer about backflow protection to keep pit water from being drawn back into the house lines.

Drying the space, not just draining it

A pump removes liquid water; it does nothing about moisture rising from bare dirt or damp summer air. DOE guidance calls for polyethylene of 6 mil or thicker covering the whole crawl space floor, run at least 8 to 12 inches up walls and piers (to outside ground level is better), with seams overlapped 6 to 12 inches and taped. The EPA recommends keeping indoor humidity below 60%, ideally between 30% and 50%, which a dedicated crawl space dehumidifier can help with once the space is sealed.

If water does get in, move fast. The EPA says water-damaged areas and items should be dried within 24 to 48 hours to prevent mold growth. Pump or vacuum out standing water, pull out soaked insulation and run fans.

When the water came from a pipe

Crawl space supply lines sit in unheated air, and a hard freeze can split them. If water is pouring in from above rather than seeping up, shut off the main first and follow our steps for the first minutes after a burst, then line up pipe repair. Before the next cold snap, read up on keeping Georgia pipes from freezing.

Not sure whether the problem is drainage or plumbing? A plumbing inspection under the house can rule out leaks before you spend on a pump. Help is available across the region, from Marietta to Decatur; see all the towns covered.