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ANCHOR BOLT: A heavy threaded bolt embedded in a foundation to secure a sill to foundation wall or bottom plate of exterior wall to concrete floor slab.
APRON: A pad of non-erosive material designed to prevent scour holes developing at the outlet ends of culverts, outlet pipes, grade stabilization structures, and other water control devices.


BACKFILL: The replacement of excavated soil back into a trench, hole or against a structure.
BACKFLOW: The unintended reverse flow of a liquid that can lead to contamination of the source.
BACKFLOW PREVENTER: A device or means to prevent back flow into the potable water supply. (RPZ Valve)
BELOW GRADE: That portion of a building or structure that is located below ground level.
BENCHMARK: A mark on a permanent object indicating elevation and serving as a reference mark for land surveys.
BERM: A narrow shelf or flat area that breaks the contiguity of a slope.
BID: A written offer prepared by a party to enter into a contract with another (see Letter of Intent or Offer Letter).
BIOLOGICAL CONTROL: A method of controlling pest organisms by means of introduced or naturally occurring predatory organisms, sterilization, the use of inhibiting hormones, or other means, rather than by mechanical or chemical means.
BIOFILTRATION SWALE: A sloped, vegetated channel or ditch that provides both conveyance and water quality treatment to storm water runoff. It does not provide storm water quantity control but can convey runoff to BMP’s designed for that purpose.
BIORETENTION: A storm water management device that consists of an excavated basin or trench that is filled with porous media and planted with vegetation.
BMP or BEST MANAGEMENTANAGEMENT PRACTICE: activities or structural improvements that help reduce the quantity and improve the quality of storm water runoff.
BOOM: a floating device used to contain oil or floating debris on a body of water.
BORROW PIT: An excavated area where soil, sand or gravel has been dug up for use elsewhere.


CAST-IN-PLACE CONCRETE: Concrete that is poured into forms that are erected at the job site. It is the same as the term site casting. See pre-cast concrete.
CATCH BASIN: need to change this one to an entryway to the storm drain system, usually located at street corners and the bottoms of hills.
CATCHMENT DEVICE: a device installed at some location in the storm drain network designed to trap litter, sediment, and/or oil before it enters the watershed.
CERTIFICATE OF OCCUPANCY (C of O): A document issued by the local governmental authorities – usually the building department - that states that the building or inhabited space is in compliance with law and in a safe and proper condition to be occupied.
CFM (Cubic Feet per Minute): A rating that expresses the amount of air a blower or fan can move. The volume of air (measured in cubic feet) that can pass through an opening in one minute.
CHANGE ORDER: A document usually signed by the tenant when making revisions to the original construction drawings or build-out plans. It is the tenant’s written authorization to revise the plans and usually indicates the tenant’s willingness to pay for the revisions.
CIVIL ENGINEER: A licensed professional engineer that mostly deals with the design, construction and/or maintenance of infrastructure. A Civil Engineer can specialize in one of several sub-disciplines (i.e., Structural, Environmental, Geotechnical, Transportation, Construction, etc) and serve the public sector through the municipal and federal levels.
CLAY TILE: tile made from clay that has been forced through an extruder, cut to size, air-dried and then fired in a kiln.
CMU CONCRETE MASONRY UNIT: masonry unit made from Portland cement and aggregate may or may not have pigment added. CMU is the most common type of block.
CONTAMINANT: a substance that adds impurities
CONTOUR: The surface configuration of land.
CUBIC YARD: a three dimensional volume measurement equal to the amount contained by a cube that is one yard wide, one yard long, and one yard high. Each cubic yard contains 27 cubic feet.
CULVERT: A closed conduit used for the conveyance of surface drainage water under a roadway, railroad, canal, or other impediment.
CURB INLET: is typical a below ground box structure with a vertical throat opening is placed in the curb at street level to collect surface water which drains into piping system.


DAMP PROOFING: A process used on concrete, masonry or stone surfaces to repel water, the main purpose of which is to prevent the coated surface from absorbing rain water while still permitting moisture vapor to escape from the structure. (Moisture vapor readily penetrates coatings of this type.) "Damp proofing" generally applies to surfaces above grade; "waterproofing" generally applies to surfaces below grade or an application or system that is installed when the house is built to resist water vapor or minor amounts of moisture and acts as a backup to primary waterproofing systems. Damp proofing materials are subject to the effects of weathering and deterioration and are not effective against water pressure. This is most often a spray, brush or rolled on type sealer that will repel water but will not span any type of shrinkage crack or structural separation.
DE-HUMIDISTAT: A control mechanism used to operate a mechanical ventilation system based upon the relative humidity in the home.
DEMOLITION: The systematic deconstruction of a property’s improvements, usually by manual or mechanical means. Since it usually includes buildings, site work, etc and the possible hazards and contaminants that could be present, there are numerous steps that need to take place prior to the removal of a structure (including asbestos abatement, obtaining demo permits, submitting necessary notifications, disconnecting utilities, rodent baiting, and development of site-specific safety and work plans (Fencing, etc.).
DETENTION: managing storm water runoff by temporary holding and controlled release.
DOWNSPOUT: a pipe for draining water from roof gutters. A downspout is also called a leader. The pipe from the roof gutter system that, in conjunction with the leaders, directs the roof water away from the foundation or a vertical pipe that carries water from the gutter, along the side of the structure to the ground or drainage system.
DOWNSPOUT EXTENSIONS: solid pipe that extends from the end of a downspout, usually 6-10 feet from the foundation wall, to keep excessive water from the foundation. Always recommended!
DRAIN FIELD: a series of pipes through which WASTE is released into the soil after it has been treated in the septic tank. The size of the drain field depends on the number of people being serviced by the system and the ability of the soil to absorb liquid.
DRAINRAIN 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.
DUMPSTER: Metal bin-style trash containers designed for construction debris. Dumpsters vary in size typically from 10 yards to 30 yards.


EASEMENT: a right to use portions of land that is not owned by the user (a right of way). Easement Agreements are written contracts that may include a survey or metes and bounds descriptions to demonstrate the exact lines and position.
EFFLORESCENCE: The staining and discoloring of masonry walls and floors as a result of water-carried acids and chemicals. Often confused with mildew in appearance. An encrustation of soluble salts, commonly white, deposited on the surface of stone, brick, plaster, or mortar; usually caused by free alkalis leached from mortar or adjacent concrete as moisture moves through it. In chemistry, Efflorescence is the loss of water (or a solvent) of crystallization from a hydrated or solvated salt to the atmosphere on exposure to air.
PRIMARY EFFLORESCENCE: is named such, as it typically occurs during the initial cure of a cementitious product. It routinely occurs in masonry construction, particularly brick, as well as some fire stop mortars, when water moving through a wall or other structure, or water being driven out as a result of the heat of hydration as cement stone is being formed, brings salts to the surface that are not commonly bound as part of the cement stone. As the water evaporates, it leaves the salt behind, which forms a white, fluffy deposit, that can normally be brushed off. The resulting white deposits are referred to as "efflorescence" in this instance. In this context efflorescence is sometimes referred to as "salt petering." Since primary efflorescence brings out salts that are not ordinarily part of the cement stone, it is not a structural, but, rather, an aesthetic concern. For controlling primary efflorescence, formulations containing liquid fatty acid mixtures (e.g., oleic acid and linoleic acid) have been commonly used. The oily liquid admixture is introduced into the batch mix at an early stage by coating onto the sand particles prior to the introduction of any mix water, so that the oily admixture is distributed uniformly throughout the concrete batch mix.
SECONDARY EFFLORESCENCE: is named such as it does not occur as a result of the forming of the cement stone or its accompanying hydration products. Rather, it is usually due to the external influence of concrete poisons, such as chlorides. A very common example of where secondary efflorescence occurs is steel reinforced concrete bridges as well as parking garages. Saline solutions are formed due to the presence of road salt in the winter. This saline solution is absorbed into the concrete, where it can begin to dissolve cement stone, which is of primary structural importance. Virtual stalactites can be formed in some cases as a result of dissolved cement stone, hanging off cracks in concrete structures. Where this process has taken hold, the structural integrity of a concrete element is at risk. This is a common traffic infrastructure and building maintenance concern. Secondary efflorescence is akin to osteoporosis of the concrete. For controlling secondary efflorescence, admixtures containing aqueous-based calcium stearate dispersion (CSD) are often added at a later stage of the batching process with the mix water. In a typical batching process, sand is first charged into the mixer, then the oil-based primary anti-efflorescence admixture is added with constant mixing to allow the oil to coat the sand. Then coarse aggregates, colorants, and cement are added, followed by water. If CSD is used, it is then introduced usually at this point during or after the addition of the mix water. CSD is an aqueous dispersion wherein fine solid particles of calcium stearate are suspended in the water uniformly. Commercially available CSD has an average particle size of about 1 to 10 microns. The uniform distribution of CSD in the mix may render the resulting CMU water repellent, as CSD particles are well distributed in the pores of the unit to interfere with the capillary movement of water.
PROTECTING AGAINST EFFLORESCENCE: it is possible to protect porous building materials such as brick, tiles, concrete and paving against efflorescence by treating the material with an impregnating, hydro-phobic sealer. This is a sealer which repels water and will penetrate deeply enough into the material to keep water and dissolved salts well away from the surface. However, in climates where freezing is a concern, such a sealer may lead to damage from freeze/thaw cycles. Efflorescence can often be removed using phosphoric acid. After application the acid dilution is neutralized with mild diluted detergent, and then well rinsed with water. However, if the source of the water penetration is not addressed efflorescence may reappear. Common rebar protective measures include the use of epoxy coating as well as the use of a slight electrical charge, both of which prevent rusting. One may also use stainless steel rebar. Certain cement types are more resistant to chlorides than others. The choice of cement, therefore, can have a large effect upon the concrete’s reaction to chlorides.
ENERGY DISSIPATER: a rock pad constructed at inlets/outlets to prevent erosion, or a constructed percolation trench to disperse out letting flows over a large area, or a catch basin used to slow fast flowing runoff. Catch basins may be a part of the dispersion trench.
ELEVATION: A drawing that depicts the exterior design of a building or structure.
EROSION: the group of natural processes, including weathering, dissolution, abrasion, corrosion, and transportation by which material is worn away from the earth’s surface.
EXERT: when referring to an infall catchment device, a screen or grate placed on top of a storm drain catch basin to prevent litter and vegetation from being washed into the storm drain by storm water.
EXTERIOR WATERPROOFING: Exterior waterproofing prevents water from entering foundation walls therefore preventing the wicking and molding of building materials. Waterproofing a structure from the exterior is the only method the IBC (International Building Code) recognizes as adequate to prevent structural damage caused by water intrusion. Prior to the 1980’s much of the original exterior waterproofing was actually damp-proofing using a degradable asphalt-based covering. Today, however, Polymer products such as Tremco’s Paraseal membrane will completely waterproof an exterior foundation wall. This material has a half life in the thousands of years which makes it ideal for a long term exterior waterproofing solution. Asphalt and tar based compounds are affected by soil pH and break down after 10-20 years, thus making that type of waterproofing ineffective over time.


FLUME: a constructed channel lined with erosion-resistant materials used to convey water on the steep grades without erosion.
FOOTERS: help distribute the weight of the foundation and building evenly throughout the entire foundation.
FOOTING: the base or bottom of a foundation wall, pier or column, which functions to distribute the weight of a load-bearing column over a larger area. or Footing / Footer (See Understanding Residential Construction) concrete poured into a form below the frost line and above the normal water table and allowed to cure. This then becomes the base upon which the walls are built and helps to distribute the load. A footing is a lower level pier support which is used to support non-load bearing areas like patios, porches or small enclosed additions. They are less expensive on average and will not cause structural damage when being placed under such small areas that do not have a thick beam.
FOREBAY: an easily maintained, extra storage area provided near an inlet of a BMP to trap incoming sediments before they accumulate in a pond or wet land BMP.
FOUNDATION: the portion of a building’s structure that transfers the weight of the building into the ground. A buildings foundation is typically constructed of concrete and/or concrete block. Or This STRUCTURAL PART rests on the FOOTING and supports the exterior walls and floor system.
FOUNDATION DRAINS: these drains are located at the bottom of the foundation walls whether it is a basement or a crawl space foundation. The drain may be on the footing, against some type of drain media or on the side of the footing, either way is correct if installed properly. Some of the newer waterproofing systems require the foundation drain to be on the footing, in contact with the drain media.
FRENCH DRAIN SYSTEM: a crushed rock drain system, constructed of perforated pipes, which is used to drain and disperse wastewater.


GRAVITY DRAIN: Pipe placed at a downward slope grade into encourage water to flow through the pipe.
GROUNDWATER: water concentration below the surface of the ground. The level of this water in the soil is called the "water table".
GULLY: A channel caused by the concentrated flow of surface and storm water runoff over unprotected erodible land.


HUMIDITY: The measurement of water vapor in the air.
HYDROSTATIC PRESSURE: still water pressure. Often caused by a high water table it is the pressure exerted against the foundation by various heights of water at rest. The same type of pressure you feel when you try to push a bucket into a pool of water. To some degree, this is the same pressure that allows gigantic ocean liners to stay afloat but this pressure has an adverse effect on the integrity of the foundation of a building.


IMPERVIOUS SURFACE: a hard surface area which either prevents or retards the entry of water into the soil. Common impervious surfaces include roof tops, walkways, patios, driveways, parking lots or storage areas, concrete or asphalt paving, gravel roads, packed earthen materials, and oiled surfaces.
INFALL: a place where water enters the storm drain network, including curb inlet storm drains and flat grate storm drains.
INFILTRATION: passage or movement of water into the soil.
INLET: An entrance into a ditch, storm sewer, or other waterway.
INSULATION (Thermal): any construction materials that offers resistance to noise, heat, fire, etc.
INVERT: the lowest point on the inside of a sewer or other conduit.
INSERT: when referring to an infall catchment device, a device placed inside a storm drain catch basin to prevent litter, vegetation, oil, and sediment from entering the watershed.


LEGEND: The reference area on a map that lists and explains the colors, symbols, line patterns, annotations and the map’s scale.
LEECH FIELD: A method used to treat/dispose of sewage in rural areas not accessible to a municipal sewer system. Sewage is permitted to be filtered and eventually discharged into a section of the lot called a leech field.


POSITIVE DRAINAGE: is the expression used to describe the soil laid around the perimeter of the home in a way that water moves away from the house. Minimum grading is a 2" drop over 2’. This prevents water from ponding around the perimeter of house causing migrating water and helps control the moisture content of the soil. The drainage condition of a roof where all water is gone from the roof surface within forty-eight hours of precipitation during normal drying conditions.


SATURATION: in soils, the point at which a soil or aquifer will no longer absorb any amount of water without losing an equal amount.
SEPTIC TANK: holding tank which treats WASTE with the help of bacteria and discharges clarified liquid into the soil through a DRAIN FIELD.
SEDIMENT: solid material (both mineral and organic) that is in suspension, is being transported, or has been moved from its site of origin by air, water, gravity, or ice and has come to rest on the earth’s surface.
SEDIMENTATION: the process that deposits soils, debris and other materials either on the ground surfaces or in bodies of water or watercourses.
SLAB: a concrete slab is a horizontal, usually steel reinforced structural element typically between 4" and 8" thick, most often used to construct floors in commercial buildings, thinner slabs are also used in exterior paving and walkways.
SILT: oil fraction consisting of particles between 0.002 an 0.05 mm in diameter. or soil textural class indicating more than 80% silt.
SILT FENCE: a fence constructed of wood or steel supports and either natural (e.g. burlap) or synthetic fabric stretched across area of non-concentrated flow during site development to trap and retain on-site sediment due to rainfall runoff.
SLOPE: the incline angle of a sidewalk or road surface, given as a ratio of the rise (in inches) to the run (in feet).
SOAK AWAY: a pit into which surface water is drained to infiltrate into the ground.
SPALL: to flake or split away, indicates the loss of stone. The crumbling or breaking off in small pieces of concrete or masonry usually as a result of the freeze-thaw cycle or deterioration (rusting) of reinforcing steel or tie-rods.
SPALLING: describes surface failure in which chips are shed from a contact point. This is due to the maximal shear stress being not at the surface but just below it. One form of spalling occurs due to moisture freezing inside cracks in rock, cracking off the outer surfaces. Spalling can occur on a concrete surface if exposed to salt or if improperly finished.
SPOIL: dirt or rock removed from its original location-destroying the composition of the soil.
SPILLWAY: A passage such as a paved apron or channel for surplus water over or around a dam or similar obstruction. An open or closed channel, or both, used to convey excess water from a reservoir. It may contain gates, either manually or automatically controlled, to regulate the discharge of excess water.
SPRING: an area where a rapid or continuous discharge of water flows from a groundwater source in sediment or bedrock.
SQUARE FOOT: a measurement consisting of an area one foot high by one foot long.
STORM WATER MANAGEMENT: practices developed in an attempt to reduce the negative impacts of storm water on stream and watershed health.
STORM SEWER: a sewer that carries storm water, surface drainage, street wash, and other wash waters but excludes sewage and industrial wastes. Also called storm drain.
STORM WATER RUNOFF: the water derived from rains falling within a tributary basin, flowing over the surface of the ground or collected in channels or conduits.
SUBSURFACE DRAIN (SSD): a pervious backfield trench, usually containing stone and perforated pipe, for intercepting groundwater or seepage.
SUMP-PIT: a large plastic bucket/barrel inside the home designed to collect ground water from a perimeter drain system. A hole dug to a depth that would accommodate a sump pump and serve as a collection receptacle for water. A sump well liner or crock is usually placed in the pit to keep the walls of the hole from collapsing and should have a bottom on them so dirt doesn’t get pumped out with the water and undermine the foundation.
SUMP PUMP: a mechanism for removing water or wastewater from a sump or wet well. Together they work to prevent basement flooding, water damage and costly repairs. It is also a submersible pump in a sump pit that pumps any excess ground water to the outside of the home.
SURFACE RUNOFF: precipitation that flows onto the surfaces of roofs, streets, the ground, etc., and is not absorbed or retained by that surface but collects and runs off.
SWALE: an elongated depression in the land surface that is at least seasonally wet, is usually heavily vegetated, and is normally without flowing water. Swales conduct storm water into primary drainage channels and may provide some groundwater recharge.


TOE OF SLOPE: the base or bottom of a slope at the point where the ground surface abruptly changes to a significantly flatter grade.
TILE DRAIN: pipe made of perforated plastic, burned clay, concrete, or similar material, laid to a designed grade and depth, to collect and carry excess water from the soil.


VAPOR BARRIER: a moisture-impervious layer applied to the surfaces enclosing a humid space to prevent moisture travel to a point where it may condense due to lower temperature.


WEIR: device to meter the flow of water.
WATERSHED: the whole region or extent of land which contributes to the supply of a river, lake, or other body of water.
WATERPROOFING: process of coating the part of the FOUNDATION system that will be below the soil level with a material that can withstand long term exposure to water. Not the same as DAMP PROOFING which can only withstand short term exposure to water or high quality below grade moisture protection. Used for below grade exterior concrete and masonry wall damp proofing to seal out moisture and prevent corrosion. Normally looks like black tar.
WATER REPELLANT (COATING): a coating or sealer applied to the surface of concrete and masonry surfaces to repel water.
WATER VAPOR: moisture existing as a gas in air.
WATERATER PENETRATION / WATER SEEPAGE / WATER LEAKS / LEAKAGE: the condition where water enters the interior areas of a structure.
WATERPROOFING (also see BASEMENT WATERPROOFING): waterproofing is a science designed to keep water out of buildings, through the roofing, the siding, the foundation walls, and specifically, basements. Water, in its many forms, is the number one concern for residential and commercial properties in the U.S. and especially in the D.C. Metro Area. The source of water is primarily from rainfall, snow melt, and sometimes irrigation on the surface. In many areas of Maryland, Virginia, and D.C., the groundwater table is near or above the basement floor level at various times during the year. There are three basic lines of defense against water problems in basements: (1) surface drainage, (2) subsurface drainage, and (3) waterproofing on the wall surface. The goal of surface drainage is to keep water from surface sources away from the foundation by sloping the ground surface and using gutters and downspouts for roof drainage. The goal of subsurface drainage is to intercept, collect, and carry away any water in the ground surrounding the basement. Waterproofing, the final line of defense, is intended to keep out water that finds its way to the wall and floor of the structure, or in many instances involving existing structures, keep out water which is already finding its way through the wall, floor, or both.
RESIDENTIAL BASEMENT WATERPROOFING: water may enter a basement through various means including through joints, walls, or floors (See Causes and Solutions). Various basement waterproofing systems address these problems and are available with varying cost, effectiveness, and installation invasiveness, depending on what company you hire, their level of experience, and whether they have adapted new technology, instead of using older methods and materials, which are not as effective and are sometimes obsolete. Components of a subsurface system can include porous backfill (sand and gravel / aggregate), drainage mat materials or insulated drainage boards, and perforated drainpipes (drain tile) in a gravel bed alongside the footing, or inside beneath the slab that drain to a sump or to daylight. We now have new polymer-based-materials, as well as more advanced membrane materials. Local conditions and a thorough inspection can determine which of these subsurface drainage system components, if any, are recommended for a particular site.
EXTERIOR AND INTERIOR WATERPROOFING AND DRAINAGE: 1. Exterior or Positive side applications – Waterproofing materials like epoxy, polyurethanes, waterproofing cement, tar, rubber, pre-molded membranes, drainage mats, etc., are used to waterproof and vapor seal the walls before water can penetrate through to the inside. (Your builder actually had to do this to pass inspection to sell the home.) Proper installation of perimeter drain tile in gravel, alongside the footing, always below the floor slab level, should take care of drainage issues. With existing structures, Exterior / Positive Side methods require excavation, sometimes down to the bottom or next to the foundation or footing (often called footer). Exterior methods of waterproofing can be very effective but are usually more expensive, sometimes prohibitive depending on the application, the company, and other factors. However, sometimes you have no choice. When structural issues are in evidence, outside excavation and repair may be the only solution recommended by an engineer (engineer’s report), necessary for a permit, and to be approved by a city, county, or municipal inspector. 2. Interior or negative side applications – Here, we are allowing the water to penetrate to a certain extent, and managing or stopping its direction or flow. Water, which enters at the cove, can be diverted to a sub-floor drainage system. At the end of this drainage system is a sump pump or two, which discharges the water outside and away from the home. However, if water is coming through the wall, the fix is not so simple – a wall system has to be devised to manage that specific flow. When properly installed, the sub-floor, interior system may be just as effective or more so than exterior drain systems, often at a fraction of the cost. Sometimes, not! Interior Drain Tile and Water Management Systems are commonly recommended to address water, which seeps through the cove (where the floor and wall meet) or through floor cracks.


YARD (of concrete): one cubic yard of concrete is 3’ x 3’ x 3’ in volume, or 27 cubic feet. One cubic yard of concrete will pour 80 square feet of 3.5’ sidewalk or basement/garage floor.
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