Adhesion: Refers to the attraction between two molecules, each having regions of low level positive and negative charge.
Air-gap membrane: A dimpled membrane, typically manufactured using a high density polyethylene, impermeable to water and water vapour, that creates an air gap between the membrane and a foundation wall. Water between the air-gap membrane and the foundation wall flows freely towards the weeping tile. It also provides a capillary break between the foundation wall and the saturated soil surrounding it.
Backwater valve: A backwater valve is a device installed in a drain system that automatically closes to prevent sewage in an overloaded sewer line from backing up into your basement. A properly installed backwater valve should be located to prevent sewage from coming through any fixtures in your basement, such as sinks, toilets, showers and laundry tubs.
Capillary break: A barrier that prevents the flow of moisture through the small interconnected pores in concrete due to adhesion and surface tension. Also referred to as “wicking”.
Caulk: To install or apply a sealant across or into joints, cracks, or crevices to prevent the passage of air or water.
Cold joint or cold pour: An unplanned joint or discontinuity in poured concrete structures resulting from a delay in placement of sufficient time to preclude a chemical union of the material in two successive pours.
Control joint: A formed, sawed, or tooled groove in a repair surface to create a weakened plane and regulate the location of cracking resulting from restrained contraction of the material. Such provisions are also termed control relief joints. Adequately designed and constructed, these joints serve to eliminate random surface cracks by gathering, distributing and dissipating stress forces resulting from temperature and moisture variations.
Dampproof: Resistant to dampness or the effects of dampness. Also means to make dampproof.
Damp-proofing: Treatment of a surface or installation of a technology to resist the passage of moisture caused by differences in moisture content, vapour pressure and temperature across the basement envelope to prevent accumulation of water against the outer surfaces of the envelope (walls and floor slab). Concrete is dampproofed in order to control the absorption and migration of water. Damp-proofing is not the same as waterproofing.
De-watering: With respect to concrete block foundations, involves the removal or draining of water that has accumulated within concrete blocks.
Drainage: The process associated with draining water.
Drain tile: Also referred to as Weeping tile.
Dry well: A dry well is an underground excavated area filled with stone that disposes of water, most commonly drainage runoff, by dissipating it into the ground, where it merges with the local groundwater.
Efflorescence: A deposit of white salts left on a surface when a solution containing the salts leaches from concrete or masonry and then evaporates.
Epoxy injection: A method of sealing or repairing cracks in poured concrete by injecting epoxy adhesives into the cracks in order to fill them.
Evaporative moisture cooling: A phenomenon whereby moisture that evaporates imparts a cooling effect upon the material that is damp or wet.
Floor drain backwater valve: A check valve that prevents the backflow of water from the municipal storm sewer system to your basement floor drain.
Footing: A footing is a poured concrete structure embedded below the frost line, and is typically twice the width of the wall that it supports. The footing transfers the weight of the foundation walls to the soil or bedrock beneath it.
Footing drain: See Weeping tile.
French drain: A French drain, drain tile, perimeter drain or land drain is a ditch covered with gravel or rock that redirects surface and ground water away from an area. A French drain can have hollow pipes along the bottom to quickly disperse water that seeps down through the upper gravel or rock. French drains are common drainage systems, commonly used to prevent ground and surface water from travelling towards the foundation.
Frost line: Also referred to as frost depth or freezing depth — is most commonly the depth to which the groundwater in soil is expected to freeze. The frost depth depends on the climatic conditions of a given geographic area, the heat transfer properties of the soil and adjacent materials, and on nearby heat sources. In Southern Ontario the frost line is typically 3′ below grade.
Grade: This typically refers to the pitch of a slope such as a hill, road or railway; with respect to waterproofing, it is the height of the soil, or other surface, surrounding the foundation.
Gravity feed: The movement of materials from one location to another by force of gravity.
Ground water: Is water located beneath the ground surface in soil pore spaces and in the fractures of rock formations.
Hairline crack: A crack in an exposed concrete surface that is barely visible because of its extremely narrow width.
Honeycombing: Refers to voids in concrete caused by the mortar not filling the spaces between the coarse aggregate particles.
Hydrophilic: Typically means “a love of water”. In the context of polyurethane injection resins, a hydrophilic polyurethane is attracted to and dissolves well within water.
Hydrophobic: Refers to “a fear of water”. In referring to the properties of polyurethane and epoxy resins, the hydrophobic resin molecules cluster together upon exposure to water; similar to how cooking oils tend to cluster together even after they are dispersed.
Hydrostatic pressure: The force that is exerted on an underground structure by the water that is in the ground surrounding the structure.
Interior perimeter drain: Refers to the installation of a perimeter drain pipe, that functions in a similar way to weeping tile, along the inside perimeter of the basement walls beneath the floor slab.
Infrared thermography: A non-destructive testing method for locating delaminations in pavements and bridge decks and detecting moist insulation, concrete, and wood in buildings; the presence of flaws within concrete affects the heat conduction properties of the concrete and the presence of defects is indicated by differences in surface temperatures when the test object is exposed to correct ambient conditions. In the waterproofing industry it is typically used to detect moisture behind closed walls by detecting evaporative moisture cooling (EMC).
Membrane: A layer of material, typically impermeable, used as a lining on outdoor concrete walls. See also, air-gap membrane.
Mildew: Usually white in appearance, is the superficial growth of fungi on organic materials, such as wood.
Mold (mould): The growth of minute fungi that form on organic matter, often the result of decay due to exposure to moisture/dampness.
Negative side waterproofing: Applying waterproofing to the side of a structural element opposite the one subjected to hydrostatic pressure (always the inside wall surface).
Perimeter drain: See Weeping tile.
Polyurethane injection: A method for sealing or repairing cracks in concrete by injecting polyurethane resin.
Positive side waterproofing: Applying waterproofing material to the side of a structural element subjected to hydrostatic pressure (always the outside wall surface).
Radon: A colourless, odourless, radioactive gas that occurs naturally as a result of the decay of radium. It is found to varying degrees as a component of soil gas in all regions of Canada and is known to enter dwelling units by infiltration into crawl spaces and basements. The presence of the decay products of radon in sufficient quantity can lead to increased risk of lung cancer.
Reentrant cracks: Cracks at the corner of windows and other openings that are usually the result of stress build-up at the corner(s).
Relative humidity: Humidity is typically measured as relative humidity (RH). RH is a percentage value that indicates the amount of moisture in the air relative to the maximum amount the air can hold at a given temperature. Cold air is able to hold less moisture than warm air; hence, the air is dry during the winter and humid in the summer.
Repointing: See Tuck pointing.
Sanitary sewer: A large pipe buried beneath the street that is designed to transport wastewater from your home. This consists of water from sanitary fixtures (toilets, sinks, etc.) and floor drains inside your house, and in some areas, such as older areas in Toronto, includes groundwater from weeping tile installed at the base of the foundation around your home.
Seepage: To pass or flow gradually through a porous substance.
Sill plate: A sill plate, or sole plate, in construction is the bottom horizontal member of a wall or building to which vertical members are attached. Sill plates are usually 2×4 lumber. In the platform framing method the sill plate is anchored to the foundation wall. The bottom of the sill plate is ideally kept 6 inches above the finished grade.
Slab: A solid concrete structure. Typically, slabs are installed as ceilings over cold cellars as well as over a gravel base for the construction of basement and garage floors.
Slump: Refers to the wetness of concrete when delivered, slump is measured on a scale of 1 to 12 with 1 being the driest mix.
Snap rod: A rod which is used to hold concrete forms in place when building a poured concrete foundation. It is called a snap rod because, once the concrete has cured and the forms have been removed, the protruding rods are snapped off (usually with a hammer); thus providing a smooth concrete surface.
Spalling: The chipping, splintering, and breaking into smaller pieces of poured concrete, concrete blocks or cinderblocks, bricks, and stone. Spalling usually occurs when water that has permeated pourous materials freezes and causes surface deterioration (spalling).
Sporulating: To produce or release spores.
Storm sewer: A very large pipe buried beneath the street that is designed to carry storm-related water runoff on the street itself.
Sump pump: A pump used to mechanically evacuate water that has accumulated in a sump pit or liner, usually found beneath the floor in the basement of homes. The water may enter the sump pit via the perimeter drains of a basement waterproofing system such as weeping tile or an internal de-watering system, or if the basement is below the level of the local water table. Sump pumps are also used where basement flooding happens regularly and to protect against dampness where the water table is high relative to the footing of a home. Sump pumps mechanically pump water away from a house to any place where it is no longer problematic, such as a municipal storm drain or a dry well, or to the outside. In older homes, sump pumps may be connected to the sanitary sewer. Currently, this practice is not in conformance with the plumbing code and/or municipal bylaws because the volume of water coming from sump pits can overwhelm the municipal storm drain system. Powered by a home’s electrical system, sump pumps can be supplemented by a battery backup. Since a sump pit may overflow if not constantly pumped, a backup system is important for cases when the main power is out for prolonged periods of time, also, the sump pump can corrode from evaporating water in the sump pit; if a motor does not operate frequently, it is advisable to cause the motor to run at least every 3 months. There are two types of sump pumps: pedestal and submersible. The pedestal pump’s motor is mounted above the pit, where it is more easily serviced but also more conspicuous. The submersible pump is entirely mounted inside the pit, and is specially sealed to prevent electrical short circuits.
Surface repair: Repair of a concrete surface that constitutes only a small portion of the depth of a member or element.
Surface tension: A phenomenon caused by the attraction of molecules to like molecules. As molecules on the liquid surface are not surrounded by the same molecules on all sides, there is a resultant increase in their attraction to neighbouring molecules on a surface.
Swale: A shallow troughlike depression that carries water mainly during rainstorms or snow melts.
Tanking: The creation of a sealed waterproof tank for an area of a building which is commonly underground, such as a basement. The tank is formed by applying a waterproof material to the walls and the floors of the structure, either internally or externally. Tanking is synonymous with basement waterproofing.
Tie-rod hole: A hole left by the removal of a metal rod which is used to hold concrete forms in place when building a poured concrete foundation. Typically spaced 18″ apart at a height of 2′ and 5′, tie-rod holes are approximately ¾” in diameter. To ensure that water does not penetrate a foundation, tie-rod holes are usually covered, on both the inside and outside of the foundation, with a concrete patch.
Thermal imaging: The visual display of the amount of infrared energy emitted by an object using a specialized camera. This is commonly used for leak detection in building structures. See also “Infrared thermography”.
Thixotropic paste: Paste used to anchor injection T-ports to the wall which acquires a lower viscosity when mechanically agitated, and rapidly stiffens upon subsequent rest; a material having this property can be placed vertically or horizontally without sagging during the curing process. This is the type of paste used for low pressure crack injections of epoxy and polyurethane resins.
Tuck pointing: Also referred to as “repointing”, involves the placement of wet mortar into cut or raked joints for the repair of weathered joints in old or damaged masonry.
Vapor barrier: A barrier used to prevent water vapor diffusion; a vapor barrier is typically used to isolate wooden or steel framing from the concrete on which it rests.
Waterproof: Impervious to water. See also “Waterproofing”.
Waterproofing: Treatment of the surface or structure to prevent the passage of water through the building envelope under hydrostatic pressures. Waterproofing provides a full and continuous barrier to water penetration.
Water table: The level below which the ground is completely saturated with water. Also called water level. It is also known to be the depth at which soil pore spaces or fractures and voids in rock become completely saturated with water.
Weeper: See Weeping tile.
Weeping tile: A porous or perforated pipe used for underground drainage. Weeping tile is installed along the foundation footings exposed to the water table.
Wicking: The flow of moisture through the small interconnected pores in concrete due to adhesion and surface tension.
Window well: Typically a galvanized steel semi-circular structure installed to prevent the cave-in of soil and water flow into below grade basement windows.
Window well drain: A drain, similar to a kitchen sink drain, which channels window well water towards the weeping tile and its surrounding gravel layer. A window well drain prevents water from entering a basement from around the window frame or through the window itself.