The ability of a material to accept within its body, quantities of gases or liquid, such as moisture
Random, inconsequential amounts of residual water on a roof membrane.
(1) a covering made of flexible material, which may be preformed to a particular shape, used to exclude dust, dirt, moisture, etc., from around a penetration; (2) a flexible material used to form a closure, sometimes installed at inside and outside corners.
Heavy cement-based compounds and various additives that are mixed and packaged for use in a dry form; the packaged mixture is then mixed with water and liquid bonding agents to a workable concrete-like consistency.
A unit of measure of absolute viscosity. (The viscosity of water is one centipoise. The lower the number, the less viscous the material.)
A unit of viscosity; the ratio of a liquid’s absolute viscosity to the density of that liquid.
The liquid resulting from the condensation of a gas.
The conversion of water vapor or other gas to liquid phase as the temperature drops; the act or process of condensing.
To make denser or more compact, as when a material (e.g., water vapor) changes from its gas phase to its liquid phase.
Formed metal or elastomeric sheeting secured on or into a wall, curb, pipe, rooftop unit or other surface, to cover and protect the upper edge of a base flashing and its associated fasteners.
The temperature at which air becomes saturated with water vapor. The temperature at which air has a relative humidity of 100%.
A floor slab, metal wall panel, roof panel, or the like, having a sufficiently large in-plane shear stiffness and sufficient strength to transmit horizontal forces to resisting systems.
The movement of water vapor from regions of high concentration (high water vapor pressure) toward regions of lower concentration.
(1) the moisture content of a material stabilized at a given temperature and relative humidity, expressed as percent moisture by weight.
A splice or seam made in the field (not factory) where overlapping sheets are joined together using an adhesive, splicing tape, or heat- or solvent-welding.
The procedure in which a controlled amount of water is temporarily retained over a horizontal surface to determine the effectiveness of the waterproofing system.
The condition of the atmosphere with respect to water vapor. See relative humidity.
A system of perimeter and/or under slab drains used to regulate the hydrostatic pressure in the earth surrounding a below-grade structure.
Attracting, absorbing and retaining atmospheric moisture.
A continuous membrane installed under steep slope roofing materials in areas subject to ice damming that prohibits water which gets through the roof covering from getting into the structure. Must also seal the fasteners that penetrates it.
Consist of finely graded iron particles combined with an oxidizing catalyst. When mixed with water (or water, cement, and sand), the finely distributed particles expand, creating a waterproof layer that becomes a part of the surface to which it is applied.
A superficial growth produced on organic matter or living plants by fungi.
A map used to graphically define the location of moisture within a roof assembly after a moisture scan has been performed
A venting device installed through the roofing membrane to relieve moisture vapor pressure from within the roofing system.
An application where the waterproofing systems and the source of the hydrostatic pressure are on the same side of the structural element.
The ratio of the pressure of water vapor present in a given volume of air to the pressure of fully saturated water vapor at the same temperature, expressed as a percentage.
A joint formed by mating two separate sections of material. Seams can be made or sealed in a variety of ways, including adhesive bonding, hot-air welding, solvent welding, using adhesive tape, sealant, etc.
A formed metal counterflashing secured under a mechanical unit or skylight to cover and protect the upper edge of a base flashing and its associated fasteners
The movement of water vapor from a region of high vapor pressure to a region of lower vapor pressure.
The pressure exerted by a vapor of a solid or liquid when in equilibrium with the liquid or solid.
A layer(s) of material or a laminate used to appreciably reduce the flow of water vapor into a roof assembly.
Resistant to flow under stress.
A diaphragm used across a joint as a sealant, usually to prevent the passage of water.
The level within the ground, below which the soil is saturated with water.
A measure of the rate of transmission of water vapor through a material under controlled laboratory conditions of temperature and humidity. Customary units are grains/h·ft2.
The ability of individual, overlapping components to resist the passage of water without hydrostatic pressure.
Treatment of a surface or structure to prevent the passage of water under hydrostatic pressure.
The ability of a membrane or roof covering to prevent the passage of water with a limited amount of hydrostatic pressure.
A condition where free water is present in a substance.
The process of moisture movement by capillary action.