The flash point of a material is the "lowest liquid temperature at which, under certain standardized conditions, a liquid gives off vapours in a quantity such as to be capable of forming an ignitable vapour/air mixture".
Waterproofing is the process of making an object or structure waterproof or water-resistant so that it remains relatively unaffected by water or resisting the ingress of water under specified conditions. Such items may be used in wet environments or underwater to specified depths.
A leak is a way for fluid to escape a container or fluid-containing system, such as a tank or a ship's hull, through which the contents of the container can escape or outside matter can enter the container. Leaks are usually unintended and therefore undesired. The word leak usually refers to a gradual loss; a sudden loss is usually called a spill.
Waterproof fabrics are fabrics that are, inherently, or have been treated to become, resistant to penetration by water and wetting. The term "waterproof" refers to conformance to a governing specification and specific conditions of a laboratory test method. They are usually natural or synthetic fabrics that are laminated or coated with a waterproofing material such as wax, rubber, polyvinyl chloride (PVC), polyurethane (PU), silicone elastomer, or fluoropolymers. Treatment could be either of the fabric during manufacture or of completed products after manufacture, for instance by a waterproofing spray. Examples include the rubberized fabric used in Mackintosh jackets, sauna suits, and inflatable boats.
Moisture vapor transmission rate (MVTR), also water vapor transmission rate (WVTR), is a measure of the passage of water vapor through a substance. It is a measure of the permeability for vapor barriers.
A vapor barrier is any material used for damp proofing, typically a plastic or foil sheet, that resists diffusion of moisture through the wall, floor, ceiling, or roof assemblies of buildings and of packaging to prevent interstitial condensation. Technically, many of these materials are only vapor retarders as they have varying degrees of permeability.
A building envelope is the physical separator between the conditioned and unconditioned environment of a building including the resistance to air, water, heat, light, and noise transfer.
In physics and engineering, permeation is the penetration of a permeate through a solid. It is directly related to the concentration gradient of the permeate, a material's intrinsic permeability, and the materials' mass diffusivity. Permeation is modeled by equations such as Fick's laws of diffusion, and can be measured using tools such as a minipermeameter.
Building insulation materials are the building materials that form the thermal envelope of a building or otherwise reduce heat transfer.
A landfill liner, or composite liner, is intended to be a low permeable barrier, which is laid down under engineered landfill sites. Until it deteriorates, the liner retards migration of leachate, and its toxic constituents, into underlying aquifers or nearby rivers, causing potentially irreversible contamination of the local waterway and its sediments.
The HAZMAT Class 2 in United States law includes all gases which are compressed and stored for transportation. Class 2 has three divisions: Flammable, Non-Flammable/Non-Poisonous, and Poisonous. This classification is based on the United Nations' Recommendations on the Transport of Dangerous Goods - Model Regulations. In Canada, the Transportation of Dangerous Goods Regulations, or TDGR, are also based on the UN Model Regulations and contain the same three divisions.
Breathability is the ability of a fabric to allow moisture vapor to be transmitted through the material.
Bituminous waterproofing systems are designed to protect residential and commercial buildings. Bitumen is a material made up of organic liquids that are highly sticky, viscous, and waterproof. Systems incorporating bituminous-based substrates are sometimes used to construct roofs, in the form of "roofing felt" or "roll roofing" products.
Reid vapor pressure (RVP) is a common measure of the volatility of gasoline and other petroleum products. It is defined as the absolute vapor pressure exerted by the vapor of the liquid and any dissolved gases/moisture at 37.8 °C (100 °F) as determined by the test method ASTM-D-323, which was first developed in 1930 and has been revised several times. The test method measures the vapor pressure of gasoline, volatile crude oil, jet fuels, naphtha, and other volatile petroleum products but is not applicable for liquefied petroleum gases. ASTM D323-15a requires that the sample be chilled to 0 to 1 degrees Celsius and then poured into the apparatus; for any material that solidifies at this temperature, this step cannot be performed. RVP is commonly reported in kilopascals (kPa) or pounds per square inch (psi) and represents volatization at atmospheric pressure because ASTM-D-323 measures the gauge pressure of the sample in a non-evacuated chamber.
A rainscreen is an exterior wall detail where the siding stands off from the moisture-resistant surface of an air/water barrier applied to the sheathing to create a capillary break and to allow drainage and evaporation. The rainscreen is the cladding or siding itself but the term rainscreen implies a system of building. Ideally the rainscreen prevents the wall air/water barrier from getting wet but because of cladding attachments and penetrations water is likely to reach this point, and hence materials are selected to be moisture tolerant and integrated with flashing. In some cases a rainscreen wall is called a pressure-equalized rainscreen wall where the ventilation openings are large enough for the air pressure to nearly equalize on both sides of the rain screen, but this name has been criticized as being redundant and is only useful to scientists and engineers.
A duct leakage tester is a diagnostic tool designed to measure the airtightness of forced air heating, ventilating and air-conditioning (HVAC) ductwork. A duct leakage tester consists of a calibrated fan for measuring an air flow rate and a pressure sensing device to measure the pressure created by the fan flow. The combination of pressure and fan flow measurements are used to determine the ductwork airtightness. The airtightness of ductwork is useful knowledge when trying to improve energy conservation.
Epoxy moisture control systems are chemical barriers that are used to prevent moisture damage to flooring. Excessive moisture vapor emissions in concrete slabs can mean significant, expensive damage to a flooring installation. Hundreds of millions of dollars are spent annually just in the United States to correct moisture-related problems in flooring. These problems include failure of the flooring adhesive; damage to the floor covering itself, such as blistering; the formation of efflorescence salts; and the growth of mold and mildew.
Interstitial condensation is a type of condensation that may occur within an enclosed wall, roof or floor cavity structure, which can create dampening.
Building airtightness can be defined as the resistance to inward or outward air leakage through unintentional leakage points or areas in the building envelope. This air leakage is driven by differential pressures across the building envelope due to the combined effects of stack, external wind and mechanical ventilation systems.
Ductwork airtightness can be defined as the resistance to inward or outward air leakage through the ductwork envelope. This air leakage is driven by differential pressures across the ductwork envelope due to the combined effects of stack and fan operation.
