Flooded Lower Level Cleanup in Snellville

What makes a lower level in Snellville different from a flood elsewhere?

The slope and the slab. Water arrives from the high side of the lot, and the room is usually built on concrete rather than over a crawl space or a cellar.

A lower room on a slab has no void under it, so the water sits on top of the concrete and is pushed toward the lowest edge of the room. That edge is often the wall that faces the slope, and the wet line runs along it higher than the rest of the room. The moisture map has to be read with that in mind, because the wall nearest the slope is the one most likely to hide the water.

The slope also means the water is not always standing in a pool. Where the lot is steep, the water can run through the room in a sheet and leave a silt line at the threshold that looks small from the door. The photographs of the threshold and the line on the wall are the record of how much came through.

Why is the red clay soil relevant to a lower-level flood?

Because saturated clay sheds water slowly, so the yard keeps running into the house long after the rain stops.

Red clay in the Georgia Piedmont holds water at the surface when it is soaked. A yard that has taken a heavy storm does not absorb the next rain, and the runoff goes toward the lowest opening. A lower room with a patio door on that side is in its path for longer than the storm itself.

This is also why a lower-level flood can return after the water has been pumped out. The grade that slopes toward the house is the source, and the fix is outside the room. Regrading the soil away from the wall and clearing the window well are part of the cleanup, because a room that was dried but not protected from the yard will be wet again on the next long rain.

How is the finish treated in a room that has been under water?

Carpet pad is removed, the lower course of drywall is opened, and the floor and the paint are judged by the readings.

Carpet that took storm water is usually removed, because the pad holds the water against the slab for days. A hard floor such as tile or vinyl that sat in a shallow pool can often be dried in place once the joints are cleaned, but the decision is made after the readings are in.

Drywall above the wet line is usually sound and is kept, and drywall below the sill is cut out to the height of the water and replaced. The cut is made clean and above the wet edge so that the drying can reach the cavity behind it. Paint and trim are not judged until the wall reads dry.

• Remove carpet pad that held the water against the slab
• Cut the lower drywall to the height of the wet line, and no higher than the readings require
• Clean and dry the tile or vinyl joints before judging the floor
• Leave the paint and the trim until the wall reads dry on the meter

What should the owner do with the room over the next few weeks?

Keep the room ventilated, keep the readings going and do not close it up until the slab and the wall base are dry.

A room that has been dried still holds some moisture in its slab for a while. The owner is asked to keep the door open to the rest of the house, to run the dehumidifier on a schedule and to check the readings at the same spots each visit. A room that is closed up while it is still wet grows mildew on the wall paper and the trim, which is then harder to clean.

The owner also keeps the room's contents out until it is dry. Items moved into the room during the drying are placed on racks, away from the wall, and anything stored near the wet edge is checked for a musty smell. The record of readings is kept with the photographs of the lot and the flood line.

What is the work outside the room, once it is dry?

The grade, the window wells and the patio doors, because they decide whether the next storm reaches the room again.

The grade is the first thing to look at. Soil that slopes toward the wall is brought back so that it falls away from the foundation, and a low patch in the yard is filled. The window well is cleared of silt and fitted with a cover or a drain where the lot allows it, and the threshold of the patio door is checked for a gap or a low point.

A sump pit in the lower room, where one exists, is tested so that the owner knows whether it runs. Where there is no sump, the room is set up so that the next water is not trapped against the wall, and the owner is given the path the water took so that the grading work can be planned against it.