If the house has a sump pump, look down into the pit. If there is water in the pit and you are inspecting it during the dry season (the water table is usually highest during the spring), the sump pump will probably be operating continuously during the spring. Try to check the sump-pump operation. However, do not actuate a pump unless there is water in the pit. To check the operation of the pump and motor when there is no water in the pit, fill the pit using a garden hose or gently tip in a couple of large buckets of water. If you notice that the water is disappearing into the ground or under the slab before the pump has a chance to activate, wrap a plastic sheet around the wall of the pit. You may have to line the pit bottom with plastic as well. When you actuate the pump, watch the water level to see if it drops. You might find that the motor that drives the pump is operational but the coupling between the pump and the motor is broken. In this case, it will sound as if the pump is working, but it is not, and the water level will not drop. A sump pump is relatively inexpensive and can be repaired or replaced easily.
Although a sump pump is sometimes located in the low section of the floor (when it is being used to collect surface water), it should not be located where it will present a tripping hazard. (See FIG. 11-10.) The pump can be placed in a corner where it will not take up valuable floor space and can be connected to the low spot in the floor by a drainpipe placed below the floor slab that discharges into the sump pit.
After inspecting the walls and the floor for signs of water seepage, you should check the bases of items stored or standing on the floor for water stains and rust. You might find that the walls and the floor of the basement appear to be freshly painted. If you see this, you should be suspicious because the new layer of paint will cover almost all the signs of a water-seepage problem. There are some areas, however, that are often omitted when painting the basement. These should be checked for water stains and rust. Specifically, look at the base of the steps leading to the basement and in particular the back of the bottom step. Also look at the base of columns. Wood columns might have stains or may be rotting, and metal columns might be rusting. The base of the inside portion of a furnace sheet-metal casing is often overlooked when painting. Look inside. Is there extensive rust? If there is, it might have been caused by a past flood. However, it could also have been caused by a faulty humidifier, so do not jump to a quick conclusion.
Seepage indications in a finished basement Usually the finished walls in a basement are a few inches or more away from the foundation walls. Therefore, seepage indications on the foundation wall will not be reflected in the middle and upper portions of the finished wall. Look at the bottom portion of the wall for signs of water intrusion. If the wall is paneled, look for rotted and warped sections and water stains. Sometimes there are grayish mold spots or mold fungi on the walls, a condition caused by excessive dampness. With a plasterboard wall, look for water stains and blackened areas and spots. The latter is mold and mildew. In some cases, the lower portion of the plasterboard wall might have deteriorated.
Next, look at the floor. If the floor is raised above the level of the concrete floor slab, the wood flooring and the wood-framing members used to raise the floor are vulnerable to rot in the event of seepage. The wood framing below the floor should be pressure-treated but often is not. Try to walk all over the floor, especially around the perimeter. If there are any rotting sections, they will feel soft and spongy beneath your feet. If the floor is covered with resilient tiles, the rotting sections might be visible, since the dampness in the wood tends to loosen the tiles. (See FIG. 10-4.)
An area that is particularly vulnerable to water seepage is the portion of the basement that faces a yard where the overall topography is inclined toward the house. Even if the ground adjacent to the house is graded properly, there will still be subsurface water moving toward the house. The walls and the floor of the vulnerable section should always be checked for signs of seepage. Sometimes this is quite difficult; some homeowners might inadvertently (or intentionally) block the area with furniture. If the area is blocked, ask the homeowner if it is all right to move the furniture.
If the floor slab is covered with resilient tiles and there is a problem with heavy seepage through the floor, it is usually noticeable by looking at the tiles. The joints between the tiles become swollen and filled with a white crusting of mineral deposits (efflorescence). Some tiles become loose, and efflorescence is noted below them. Occasionally the tiles are covered with wall-to-wall carpeting. In this case, the tiles cannot be examined for signs of seepage. However, some checking for seepage can be done. Ask the homeowner for permission to lift the edge of the carpet off the tacking strip along a section of the exterior wall. If there is seepage in this area, the tacks will be rusted and the wood strips water stained or rotted.
If the basement is heated with baseboard convectors mounted on an exterior wall, another place to look for signs of seepage is below the convector. If there is some seepage in that area (the joint between the floor slab and the wall), the base of the convector will be rusted.
On occasion a portion of the basement might become flooded as a result of faulty plumbing, an overflowing sink or tub, a malfunctioning water heater, and so on. Flooding from the above is basically a one-time affair and will not cause the type of damage that results from repeated wetting. There will be water stains, but there usually will not be rot, peeling or flaking paint, efflorescence, or heavy rusting.