Moisture Protection Flashcards
Restricting by various means the passage or migration of water or water vapor through a building assembly or construction.
Moisture Protection
Air containing the maximum amount of water vapor possible at a given temperature.
Saturated Air
The movement of a vapor through a porous medium resulting from a difference in vapor pressure and temperature.
Vapor Migration
A dispersion in air of water molecules, esp as produced by evaporation at ambient temperatures rather than by boiling.
Water Vapor
A gas at a temperature below its critical temperature.
Vapor
The pressure exerted by the molecules of a vapor in a mixture of gases, such as the pressure exerted by water vapor in air.
Vapor Pressure
A liquid reduced from a vapor or vapor mixture, such as the water that forms when relatively humid air migrates into a region at or below the dew point of the air.
Condensation or Condensate
The condensation that occurs when relatively humid air comes into contact with a surface at or below the dew point of the air.
Surface Condensation
The gathering of moisture from the surrounding air on a surface by condensation.
Sweating
A material of low permeance, as platic film or foil, installed in a construction to retard the transmission of moisture from the interior environment to a point where it can condense into water.
Vapor retarder or vapor barrier
The time rate at which water vapor, un a unit pressure difference, is transmitted through a unit area of a material of a given thickness.
Permeance
A unit of permeance, equal to 1 grain of water vapor transmitted per 1 sq. ft. per hour per inch of mercury pressure difference.
Perm
The treatment of a masonry or concrete surface to retard the absorption of water or penetration of water vapor, either by applying a waterproof coating or by using a suitable admixture.
Dampproofing
A thin coat of cement mortar for smoothing the surface of rough masonry or for sealing a masonry wall against moisture.
Pargin or Parget
A membrane or coating applied to render a surface impervious to water.
Waterproofing
A mixture of asphalt, graded mineral aggregate, and fine mineral matter that can be poured when heated and hardens when exposed to air, used as an adhesive, as a joint sealant, and in water proofing.
Asphalt Mastic
Any of various pasty preparatins containing binuminous materials and used as an adhesive or sealant.
mastic
Open-jointed tile or perforated pipe laid aound the foundation of a building for the collection and conveyance of groundwater to a point of disposal.
Foundation Drain
Any of a class of synthetic fabrics used to separate soil materials, filter fine soil particles from a drainage medium, or control soil erosion.
Geotextile
A geotextile fabric that allows water to pass freely into an underground drainage medium but prevents fine soil particles from entering and clogging the system.
Filter Fabric
A two-part material for draining groundwater, such as from behind a foundation or retaining wall, consisting of synthetic matting or an eggcrate core, faced on one or both sides with a filter fabric.
Drainage Mat
A layer or fill of crushed rock or gravel placed to ensure adequate drainage of groundwater while preventing the entry and flow of sediment and silt.
Gravel Drain
A metal strip interlocking with and securing a cap flashing.
Cap receiver
Flashing turned down to protect base flashing and prevent water from entering the joint.
Cap flashing, counterflashing
Flashing covering and protecting the joint between a roof and the vertical surface of a wall, parapet or chimney.
Base Flashing
An inclined or beveled strip changing the pitch of a roof slope or rounding out the angle between a flat roof and a parapet.
Cant Strip
Pieces of sheet metal or other thin, impervious material installed to prevent the passage of water into a structure from an angle or joint.
Flashing
Flashing that extends from one side of a wall to the other.
Through-wall Flashing
A slight bend in the edge of a flashing forming a capilarry break.
Feint
Wall construction employing a rainscreen to eliminate any difference in air pressure between the exterior and the interior that would cause rainwater to move through joints in the wall.
Pressure-equalized design
A concept for preventing the penetration of wind-driven rain through a wall, utilizing a rainscreen backed by a confined air space to shiled an inner barrier where the primary air and vapor seals are located.
Rainscreen Principle
An exposed outer layer of a wall, having openings designed to deter the penetration of rainwater and to equalize the air pressures on opposite sides of the facing.
Rainscreen
The elasticlike force existing in the free surface of a liquid, tending to minimize the area of the surface, caused by unbalanced intermolecular forces at or near the surface.
Surface Tension
A manifestation of surface tension by which the greater adhesion of a liquid to a solid surface than internal cohesion of the liquid itself causes the liquid to be elevated against a vertical surface.
Capillary Action, Capiliarity, Capillary attraction.
To draw off liquid by capillary action.
Wick
A space between two solid surfaces made wide enought to prevent the capillary action of moisture through the space.
Capillary Break
A horizontal layer of impervious material laid in a masonry wall to prevent the capillary rise of moisture from the ground or a lower course.
Damp Course or Damp Check
A metal flashing for a vent pipe projecting above a roof deck.
Collar
A flange that fits around and provides a raintight seal for a vent pipe penetrating a roof deck.
Roof Flange
A tapered piece of lead for securing flashing in a reglet.
Lead Wedge
A groove cut or formed in a vertical surface to receive flashing.
Reglet
Flashing covering and protecting the intersection of a wall and the sloping part of a roof, consisting of L-shaped pieces that step down to follow the slope of the roof.
Step Flashing, Stepped Flashing
The distance by which one sheet of flashing overlaps another.
Passing
Material, such as mortar, used as a substitute for flashing where a sloping roof meets a wall.
Filleting
Any of various viscous substances injected into a building joint, curing to form a flexible material that adheres to the surrounding surfaces and seals the joint against the passage of air and water.
Joint Sealant
The change in width of a building joint resulting from a change in temperature.
Joint Movement
The capacity of a sealant to be extended in tension.
Extensibility
A joint sealant of polysulfide, polyurethane, or silicone capable of elongations up to 25%, used for sealing joints in curtain-wall systems.
High-range sealant
A joint sealant of butyl rubber or acrylic capable of elongations up to 10%, used for sealing nonworking or mechanically fastened joints.
Medium-range sealant
A low-range joint sealant used for filling or closing a seam, crevice or crack in order to make it watertight and airtight.
Caulk or Caulking
A joint between two successive placements of concrete, often keyed or doweled to provide lateral stability across the joint.
Construction Joint
A short reinforcing bar extending equally into two abutting sections of concrete to prevent differential movement.
Dowel
A pipe sleeve that allows the housed element to move freely in a longitudinal direction.
Expansion Sleeve
A flexible strip of rubber or plastic inserted across a concrete or masonry joint to prevent the passage of water.
Waterstop
A joint between two section of a building or structure permitting thermal or moisture expansion to occur without damage to either part. _____ also serve as isolation joints and control joints.
Expansion Joint
A prefabricated cover for protecting an expansion joint while allowing relative movement between the two parts being connected.
Expansion Joint Cover
A continous groove or separation formed, sawed, or tooled in a concrete or masonry structure to form a plane of weakness and thus regulate the location and amount of cracking resulting from drying shrinkage or thermal stresses.
Control Joint
A joint between two parts of a structure, designed to compensate for the contraction of either part.
Contraction Joint
A joint separating two sections of a structure so that differential movement or settlement can occur between the parts.
Isolation Parts
Any of various materials, such as polyethylene tape, used for preventing the adhesion of a sealant to the bottom of a joint.
Bond Breaker
A narrow deposit of sealant applied to a building joint.
Bead
The surface of a building component or joint that serves as a substrate for a sealant and to which the sealant is bonded.
Bond Face
Any material that underlies and serves as a base or foundation.
Substrate
A compressible strip, rod, or tube of resilient material, such as neoprene or butyl, used for filling a joint, and controlling the depth of a sealant.
Joint Filler, Backup Rod
