Basement Waterproofing Terminology

Acid

As the earth around your foundation settles from capillary action, the movement may shift your foundation. Since the air pressure within your basement cannont hold against outside water pressure, the imbalance of pressure may cause your walls to shift and crack. Water absorbs into your wall bringing silt along with it. This silt has an acidic quality which reacts with the adhesive (lime) in the block. This reaction deteriorates the block making it susceptible to hydrostatic pressure which leads to structural damage.

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

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

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

Footing

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.

Erosion

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.

Backfill

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.

Mold

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.

Mildew

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

Silt

Substrate particles smaller than sand and larger than clay.

Dry lock

Vapor Barrier for Basements, Attics and Crawl Spaces

Water Seepage

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

Rust

Iron oxide that forms when exposed to oxygen and moisture.

Tar

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

Exterior Footing Drain

A tube or cylinder or box that is normally installed around the exterior perimeter of the foundation footings that collects and directs ground water away from the foundation of the house.

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.

Foundation

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.

Drain Tile

A perforated, corrugated plastic pipe laid 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.

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

Masonary failures due to vertical shear

Undermining

To dig or wear away the base or foundation.

Excavation

To dig out and remove, as earth.

Water Leak

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