Capillary Action

This is the natural action by which water when in contact with a porous surface, is drawn to and absorbed by that surface. Your concrete basement floor and walls are such porous surfaces. Their porous nature allows them to absorb water like a reservoir, ready to burst. A basement has absorbed as much as 240 gallons of water during an average rain storm.

Hydrostatic Pressure

Rain, melting snow, or springs will contribute to the rising of the water table. This will result in a build-up of pressure underneath the floor and against your foundation walls. This pressure after heavy rains can cause structural damage to your foundation.


Efflorescence is a white crystalline or powdery, often fluffy/fuzzy deposit on the surface of masonry materials like concrete, brick, clay tile, etc. It’s caused by water seeping through the wall/floor/object. The water dissolves salts inside the object while moving through it, and then evaporates leaving the salt on the surface.

Cinder Block or Concrete Block/Construction Block

A pre-fabricated structural component constructed of concrete or concrete and cinders, that is utilized to construct foundation walls, retaining walls, etc.

Poured Concrete Foundation

A foundation which is made of concrete poured between two opposing forms. When the concrete is cured the foundation is one piece.


Poured concrete base upon which foundation walls, columns, or chimneys rest; usually has steel reinforcing bars.

Foundation Wall

Supporting portion of a structure below the first floor construction or below grade.

Cold Joint

A cold joint is the intersection between the end of one concrete pour and the beginning of a new pour. The basic rule is to try to avoid cold joints by pouring straight through until the job is finished. The cold joint is a weak area and could allow the entry of water.


The wearing away of land or soil by the action of wind, water, or ice.

Clay Soil

Soil, which is composed of very fine particles, usually silicates of aluminum and/or iron and magnesium. Clay soil impedes the flow of water, meaning it absorbs water slowly and then retains it for a long time. Wet clay soil is heavy and sticky, and tends to swell from the added moisture. When dry, clay soil shrinks and settles. The top layer can bake into a hard, concrete-like crust, which cracks.


The replacement of excavated earth into a trench around or against a basement or crawlspace foundation wall.

Mortar Joint

A brick being secured to another similar brick or bricks by means of mortar or grout.


Parasitic, microscopic fungi (like Penicillin) with spores that float in the air like pollen. Mold is a common trigger for allergies and can be found in damp areas, such as the basement or bathroom.


A plant disease where the pathogen occurs as a growth on the host’s surface.


Substrate particles smaller than sand and larger than clay.

Water Seepage

Water oozed through a porous material or soil. The act or process of seeping; percolation.


Iron oxide that forms when exposed to oxygen and moisture.


A viscous black liquid containing numerous organic compounds that is obtained by the destructive distillation of coal and used as a roofing, waterproofing.

Ground Water

Groundwater is water that has drained through surface layers of soil and rock until it reaches a layer of rock material through which it cannot pass, or can pass only very slowly. This results in the accumulation of water in the rock layers above this impermeable layer. The water is stored in gaps in the rock, or between the particles of which the rock is composed.

Black Mold

Mold Exposure – Black Mold – Toxic Mold – People are exposed to mold through the air they breathe, contact with skin, and ingestion. Molds need moisture, a food source, time, and to be left undisturbed. Any source of moisture within an indoor environment can be a possible contributor to a mold problem and poor indoor air quality. It has been stated simply that the best mold control, is moisture control. Many molds given the right conditions have the potential to cause ill health effects in susceptible individuals.


The lowest and supporting part or member of a wall, including the base course and footing courses; in a frame house, the whole substructure of masonry.

Weeping Tile or Drain Tile

A perforated, corrugated plastic pipe or 12”long clay pipe laid end to end at the bottom of the foundation wall and used to drain excess water away from the foundation. It prevents ground water from seeping through the foundation wall. Sometimes called perimeter drain. Weeping tile may drain to a sump pump, the storm drain or the sewers.

Sump Pump

A sump pump is a pump used to remove water that has accumulated in a sump pit. A sump pit, commonly found in the home basement, is simply a hole to collect water.

Water Table

The level below which the ground is completely saturated with water. Also called water level.

Dry Well

A hole in the ground filled with gravel or rubble to receive drainage water and allow it to percolate away.

Wall Crack

A thin and usually jagged space opened in a previously solid material.

Floor Crack

Masonry failures due to vertical shear


To dig or wear away the base or foundation.


To dig out and remove, as earth.

Water Leak

To let water or other fluid in or out through a hole, crevice, etc.



Foundation and Wet Basement Problems