Disaster Advice
Disaster Advice Disaster Advice
Disaster Advice Disaster Advice Disaster Advice
Disaster Advice
Disaster Advice
Disaster recovery and restoration can be veiled in mystery to the many who have not undertaken specific training. This glossary explains technical terms to assist both report writing and the understanding of those technical terms so often misunderstood.


The Disaster Advice Glossary and its contents are the protected copyright of Disaster Advice


A measure of the physical property damage of a content or material.


Damage Risk Assessment

An on-site review of all building and human occupancy concerns and risks by a trained professional. The damage may result in a physical danger to the occupants from building conditions. Safety Note At all times during water damage and catastrophic flooding buildings require a damage risk assessment before starting mitigation. See Phase-I Assessment



A passive or mechanical device used to control the volume of air passing through an air outlet air inlet or duct.



A procedure using a moistened cotton mop over a relatively clean surface to remove loose dusts and dirt off of a floor surface. Education Note Damp mopping is used in between cleanings for the control of dusts and dirt since this procedure helps control surface tracking of migrant materials while reducing time and money spent on more intensive maintenance procedures. Damp mopping is a process that is often used right before a floor finish is applied. Damp mopping is also a procedure where small spills can be absorbed into a cotton mop having a neutral detergent allowing for the easy pickup of the spill and applying a non-residual cleaning agent.



Moisture impervious tar-like materials that are applied to concrete on the outside foundation side protecting the structure from absorbing unwanted moisture and moisture vapor. Control measures using chemical treatments on concrete or masonry to retard the absorption or transmission of water and water vapor. Liability Note Damp-proofing sealers seldom provide the desirable effect for which they are intended or the results which were contracted. Contact the manufacturer or distributor of the product for written warrantees and guarantees incase the product fails. As a contractor make sure the products that are used and installed are installed in strict accordance with product labelling.


Daseline Data

Building and environmental information which are gathered to determine the accumulations of biological chemical toxins and other physical properties. The baseline data of acceptable indoor air quality including thermal physical and respirable measurements. c The baseline data of acceptable indoor air quality verses outside air quality. d The efficiency ratio of a ventilation system to operate and separate contaminates from indoor air. e The energy efficiency of a building over time. See Background Measurements


Date of Agreement

The date shown on the face of an agreement or the date that an agreement has been signed.


Db Decibel

A measurement of the intensity of sound. A decibel is one tenth of a bel an increase of 1 bel is approximately doubles the loudness of a sound.


De Minimis

A legal term that states certain quantities of pollutants that are small enough to be exempt from environmental regulations.



Building materials from timber cut from trees that are considered to be dead trees.


Debris Removal

In insurance terms debris removal are those materials as debris that are part of a covered claim that must be removed as part of a loss. Education Note Most insurance policies cover debris removal expense following a loss covered under the Property Section of the policy. In some instances if the amount of loss including debris removal expenses exceeds the limit of insurance the insurance carrier may agree to pay an additional 5%u0025 of the limit of the insurance of the damaged property.



In wood the disintegration caused by the action of fungi such as wood rot. See Wood Rot Fungi



Acceptable mechanical methods to remove a certain contaminate by. Health and safety requirements and mitigation measures necessary to remove a pollutant or contaminate. Sewage Mitigation Note The physical removal of fresh gray and sewage water and its microbiological entities. The ability to salvage clean and disinfect damaged building materials and contents. c In some instances decontamination means the careful physical removal of damaged and saturated building materials. Hazardous Materials Management Note With regulated waste decontamination is the removal of hazardous substances from employees and their equipment to the extent necessary to preclude the occurrence of foreseeable adverse health effects.


Decontamination Area

One or more indoor rooms or outside areas that are specifically made and used to decontaminate workers and/or equipment.


Decontamination of Employees and Equipment

The removal of contaminates from surfaces of reusable clothing and equipment through cleaning and sanitizing. The cleaning and sanitizing of employees with good hygiene practices. Health and Safety Note No employee or equipment exposed at the job site should be released until cleaning and sanitizing has been completed.



A combination of materials finishes and furnishings that creates a particular style of interior decorating.



The dollar amount that a policy holder agrees to pay in the event of a covered loss. The insurance company pays for the remaining damage up to the limit of the policy.


Deductible Clause

In an insurance policy a deductible clause is the agreed amount to which a policy holder is responsible for during a covered loss. The insurance company will pay to repair a covered loss minus the deductible amount as shown in the declarations. The deductible shown in the declarations applies separately to each loss.


Deductible Collection

That portion of an insurance policy which the insured is personally responsible for to the restoration contractor or retailer. Legal Liability Note Caution should be taken by contractors when requesting the deductible from an insured. By accepting money the contractor is agreeing to provide services in trade. Until it can be established there is coverage for the claim the contractor may be at risk of returning the money or any future amount owed to the insured if the contractors contract states they agree to bill the insurer for the balance owed and not the insured.



The amount of money deducted from the contract sum by a written change order.



A condition or characteristic that detracts from a standard appearance strength or durability of an object or material.


Defect Latent

A defect in the manufacturing of a product that is neither apparent or visible upon reasonable inspection prior to use of the product but which becomes apparent at a later time. Legal Liability Note In the case of a latent defect the cause of the complaint should be established and the parties should come to a mutually acceptable resolution of the problem.


Defect Recourse

A process of addressing a defect within the warrantee guidelines of a manufacturer or industry. Legal Liability Note The retailer contractor or installer should notify the retailer or manufacturer of any and all visible defects prior to installation whenever such notice is possible. If the visible defect is noted by the retailer/contractor/installer and reported to the manufacturer prior to installation the manufacturer should work with the retailor/contractor for a mutually acceptable method of correction or replacement. If such notice is not possible the retailer/contractor should take reasonable action to resolve the situation with due regard to minimixing the costs that may be incurred. A retailer/contractor who knowingly installs a visibly defective merchandise without following the notification procedures outlined above or attached to the product may have no resource against the manufacture.


Defect Visible

An obvious defect that can be readily and easily discerned prior to or at the time of installation and/or prior to use.



The physical removal of standing flood waters from buildings during the emergency clean-up phase.



A chemical agent that is added to a liquid to reduce foaming problems. In carpet cleaning foaming becomes a problem when too much detergent or soap-base products are present.


Degenerative Disease

A disorder characterized by the gradual loss of some human function. For example chronic exposure to mould and bacterial toxins are known to contribute and cause gradual immune suppression.



A deterioration of a material from light humidity temperature other elements or improper use.


Degree Day

A fuel/temperature measurement based upon temperature difference and time. Education Note A degree day is used in estimating fuel consumption and specifying nominal heating loads of a building in winter. For any one day when the mean temperature is less than 65%u00B0F there exist as many degree days as there are Fahrenheit degrees difference in temperature between the mean temperature for the day and 65%u00B0F which is the base temperature in the U.S..


Degree of Compaction

The measurement of soil as related to its density its compaction based on a standard formula.


Degree of Saturation

The ratio of the volume of water in a given material to the volume of the material in its normal dry acclimatised usable state. The degree of saturation is expressed as a percentage.



The process of removing humidity. The condensation of water vapour from air by cooling it below the dewpoint or the removal of water vapour from air by chemical or physical means. Restorative Drying Note Often dehumidification can be accomplished by opening doors and windows to a dryer atmosphere and dehumidification is accellerated through forced air movement and the use of engineering controls and devises such as dehumidifiers and air movers.


Dehumidification Curve

In water damaged buildings and restorative drying the measurement of moisture in ambient air while the building remains wet as compared to the moisture measurements in ambient air while the building is in the process of drying.


Dehumidification Equipment Drying Performance

The relationship between the dehumidification equipment and its ability to function properly compared against the load of relative humidity in a wet building atmosphere and wet materials. Restorative Drying Note As far as the dehumidification equipment itself is concerned the dehumidification equipment drying performance must be considered by calculating the manufacturer performance figures charts of the dehumidification equipment to which the machine can operate efficiently at ideal ambient temperatures and humidity in the building the amperage ratings of the dehumidifier averaging 80%u00B0F. at 60%u0025 RH c the ability of the dehumidifiers compressor to increase BTUs in atmosphere at varying temperatures and humidity d the efficiency capacity of collection coils or desiccant beds to exchange moisture vapor for liquid water at varying temperatures and humidity.


Dehumidification Shock

A term used in restorative drying to describe the process and means of dramatically decreasing the ambient humidity in a wet building environment within a relatively short period of time. Education and Restorative Drying Note A dehumidification shock approach is warranted when the environment is severely wet and where time is on the side of mould growth or where secondary damage is about to occur if the trapped building water and humidity are not abated within a short period of time including a matter of hours. Large refrigerant and desiccant equipment are necessary to provide dehumidification shock. Calculating the grains of moisture in wet air making assumptions about the amount of trapped water and moisture in building materials along with temperature and humidity readings must carefully be calculated for a dehumidification shock equation before considering using this dehumidification process



An air cooler or washer used for lowering the moisture content of the air passing through it An absorption or adsorption machine designed specifically for removing unwanted moisture from air. Adjuster/Contractor Restorative Drying Note Dehumidifiers may be similar in function and design but they are not alike when it comes to restorative drying of wet buildings. Specially designed dehumidifiers are often required to dry wet buildings properly. Commercial size dehumidifiers are equipment capable of removing from 15 to 100 gallons of humidified moisture in air per day. Although a dehumidifier may function properly in a wet room the dehumidifier may not effect the dehumidification process of a wet wall ceiling or subfloor. The dehumidification of wet walls for example requires special techniques and equipment to dry the wall cavity properly and the equipment must do so within a reasonable time before mold growth occurs. See Desiccant Drying Psychometrics Refrigerant Drying Restorative Drying



The removal of water vapor from air through the use of absorbing or adsorbing materials The removal of water from stored goods. Restorative Drying Note The process of dehydration is important and must be considered as the preferred process when books documents film and other media have been effected by excessive high humidity or a flooding event.



The separating or detaching of a primary material from its composite matrix or its secondary materials. Education Note Delamination is usually is a result of wear and tear but delamination can be a result of increased exposures to environmental conditions including sun light and UV heat too little or too much humidity air movement causing drying and water damages causing release of glue and adhesive binders.



An event or condition that results in the stopping or the slowdown of a project.



The absorption of moisture from the air by certain salts in plaster or brick resulting in damp spots to appear like crystalline deposits or damp spots that appear to be darker than the surrounding material.


Deluge Sprinkler System

A dry-pipe sprinkler system designed for geographical areas that may experience temperatures at or below freezing. The dry-pipe sprinkler system is actuated by heat or smoke detection devices which then turn on valves to admit water into the dry-pipe.


Demand Control

A mechanical or electronically activated device which controls the kW demand levels in a building by shedding electrical loads when the kW demand exceeds a pre-determined set point.



The purposeful intentional destruction of part or all of a building or material.


Denitrifying Bacteria

Anaerobic sewage bacteria in soil under buildings that are capable of anaerobic respiration while using the nitrate ion as a substitute for molecular oxygen during their metabolism. See Soil-Gas



The thickness and compactness of a material. The ratio of the mass of an object to its volume.



Deodorants that are used in buildings after a flood are suppose to remove or destroy musty-like odours and other odours. Hygienists find that deodorants leave occupants with impression that odour problems have been abated which in most instances they have not. Deodorants are to be used sparingly and must not be used as a masking agent producing a false positive sense of clean air. See Masking Agents



A loss in value or worth from all causes.


Deratitis Infammation

An inflammation and/or irritation of the skin. Health and Safety Note Dermatitis inflammation can be a concern to water damage workers from excessive chemical exposures and allergic reactions associated with constant contact to flood waters and skin irritants. See Athletes Foot Contact Dermatitis


Desiccant Dehumidifiers

Machines which are designed to adsorb pints of water per hour over a bed of dessicating materials usually in the form of a wheel inside a machine. Education Note Only part of the dessicant wheel is exposed to the wet environment intake and the other part of %u005Bwet%u005D wheel is exhausted out of the dessicant machine through warm forced air and ducting. Dessicant Dehumidifiers are very effective in reducing unwanted moisture to relative humidity levels of less than 10%u0025. See Refrigerant Dehumidifiers and Dehumidification Dri-Eaz



To dry thoroughly or the process to make a material or environment dry by removing moisture content.



The removal of excess water and moisture that has adsorbed into building and content materials. See Dehumidifiers Desiccant Dehumidifiers Dehumidification


Detached Dwelling

A structure that is intended for habitation and is surrounded by exterior walls with open space.


Detached Garage

A garage which is free standing and whose exterior walls are surrounded by open space.


detaching of Vanities and Counters

In sewage contamination detaching of vanities and counters means the physical detaching of the cabinet or counter from the wall to inspect for sewage effluents or water behind and under the cabinet or counter.


Detection Limit

The smallest amount of a chemical that can be detected by a specific instrument or scientific method.



A water soluble compound capable of suspending dirt and other organics. Detergents can emulsify oils and act as a wetting agent. Caution detergents with phosphates have been banned in many parts of the nation because they are one source of pollution which cause environmental hazards to lakes and streams. Detergents residues should not be discharged into storm drains. Education Note Detergents act-like sanitizer since they suspend oils grease and organisms. Detergents need to be rinsed out and off of contaminated surfaces to work properly. Detergents work best if they are allowed to have a surface contact dwell time are agitated into a material and are used in warm water. Detergents work better than disinfectants while in the presence of dirt and oil and much bacteria such as sewage. See Eutrophication


Detergent Cleansing

In sewage contamination of salvageable but contaminated building materials detergent cleaning means warm water washing and agitation of the surface with scrub brushes or electric floor scrubber. See Rewashing Sewage Terms


Detritus Tank

A settling tank that allows debris to collect sediment without interrupting the flow of liquid.



The shearing of wood along the grain.



The moisture vapor condensed on objects at or near ground level. Dew is a result of temperature having fallen below the dew point temperature of the surrounding air.



The technical name for the mechanical removal of vast amounts of standing water from an area such as a pond a farm field a construction site or even a submersed sub-grade parking structure. Dewatering requires the use of commercial piston driven and/or diaphragm pumps having an outlet of 4%u0022 or greater. Mitigation Note The physical removal of standing sewage water and sludge off of ground. The resulting product is water saturated ground which can now be tilled remediated or aerated naturally once dewatered.



The surface temperature at which moisture will condense out of the air onto a surface The surface temperature varies with the relative humidity. With mixed ratio and barometric pressure constant the temperature to which air must be cooled in order to attain saturation by water vapour.


dewpoint Acceleration

A forced process by which the specific relative temperature and humidity results in condensation on cooling coils or desiccant beds of a dehumidifier.


Dewpoint Depression

The difference between dry bulb and dew point temperatures oF DB- oF DP.


Dewpoint Related to New Building Materials

The acclimation of new building materials in a new environment before installation. Education Note Problems related with dew point and a new atmosphere having moisture and vapor condensation problems - Concrete slabs and new flooring Concrete slabs are measured for moisture levels using the calcium chloride test method and pH tests have been conducted. Installation Note The floor covering installer has taken great pains in ensuring the project will go as error-free as possible. Several days later the flooring is installed and in less than a month blisters begin to appear and/or adhesive begins oozing from the floor covering seams. Inspectors Note The floor is opened up and inspected and it has been determined the adhesive did not cure%u0021 Next a series of events begin to take place establishing the guilt or failure of the flooring installer and/or manufacturer. Liability/Litigation Note The manufacturer is brought in to establish whether their products are defective and the litigation cycle i.e. expense time damage to customer goodwill and reputation etc. begins yet again. This all-too-familiar scenario will continue to play itself out with the current %u0022facts%u0022 creating more questions and confusion than answers. The likelihood is that this problem will continue to increase in frequency with the confusion increasing - unless the influences of dewpoint in the building are considered. Installers Note Dew point does a nearly indistinguishable imitation of classic moisture %u0022problems%u0022 that can result in real floor covering installation concerns. Yet dewpoint is in reality a transitory effect which once detected can be controlled at the time prior to installation if the installer is made aware of its existence and how to control the potential detrimental effects.


Dewpoint Temperature

A temperature at which a given water vapor content and constant pressure are capable of producing condensation of water from an atmosphere. The temperature at which any gas begins to condense. c A point in temperature which moist air becomes saturated 100%u0025 relative humidity with water vapour when cooled at a constant pressure. See Enthalpy


Dewpoint Ambient

The temperature to which indoor air must be cooled at a given pressure and water-vapour content for it to reach saturation.


Dextrin Anylin Starch Gum

A starch-based compound used for wall sizing and wallpaper adhesive. As a paste the starch is mould-loving when wet or the walls are damp for periods of time.


D-Grade Wood

Specified wood for indoor use only.



In the HVAC the differential difference is between the points where a mechanical or electronic sensor controller automatically turns %u0022on%u0022 and %u0022off.%u0022 If a thermostat turns a furnace on a 69%u00B0 and the differential is 3%u00B0 the burner will be turned off at 72%u00B0.


Differential Levelling

A method for determining the difference in elevation between two points using a level and a rod.


Differential Pressure

The difference in static pressure between two locations.


Differential Settlement

An uneven downward movement of the foundation of a structure usually caused by varying soil conditions compaction or building load resulting in cracks and distortions in the foundation and slab.



A circular square or rectangular air distribution outlet generally located in the ceiling and comprised of deflecting vanes or louvers discharging supply air in various directions and planes and arranged to promote mixing of primary air with secondary room air.


Diffusion Rate

A measure of the tendency of one gas or vapour to disperse into or mix with another gas or vapour. This rate depends on the density of the vapour or gas as compared with that of air which is given a value of 1.



The process of changing or diluting a solvent from one strength to another or a mixture of substances into another. Increasing the proportion of solvent or a diluent liquid to solute or particulate matter solid. c The process of mixing and exchanging contaminated or humidified air with less contaminated or humidified air. d The change in temperature humidity and air mass in a building with new or treated temperature humidity and air mass.


Dilution Ratio

The ratio of a solvent cleaning agent or a disinfectant concentrate to be diluted down to its recommended use.


Dimensional Stability

The ability of wood and other building materials to maintain their natural man-made or engineered configuration without undue stress. A building material capable of enduring indefinite structural effluences under normal conditions. Construction Note Building materials which under normal conditions maintain their dimensional stability but under abnormal conditions their dimensional stability can be effected by temperature stress load humidity moisture and decay.


Diminished Property Value

A proportionally smaller value to a property due to a damage. Diminished property value is a lessening or decreasing of property value as a result of some type of damage. In river flooding for example a dwelling may not have the same property value it had prior to a catastrophic loss. While the dwelling itself was repaired the overall value of the dwelling may have been affected by the environmental conditions surrounding the property. When an antique piece of furniture has been damaged it may have been professionally restored but because of the damage it may have sustained a diminished value. In a fire damaged property where antique contents are present the removal of years of patina during the cleaning and restoration process will result in a diminished property value.


Dimorphic Fungus

A filamentous fungus having the ability to exhibit alternate growth forms. A fungus exhibiting yeast-like cells at 98.6%u00B0F 37%u00B0C and exhibiting filamentous mould growth at room temperature.


Direct Costs

The labour material equipment subcontractor and other costs directly incorporated into the repair or construction.


Direct Expense

All costs that are directly incurred by or chargeable to a project or claim.


Direct Exposure Pathways

An exposure pathway where the point of exposure is at the source. The control of the direct exposure pathways requires containing the release from any other areas or parts of the building including ventilation duct air return to the building.


Direct Reading Instruments

Moisture detection instruments which give an immediate reading and indication of the percentage of moisture content in or on a material. Humidity and temperature recording instruments give an immediate readout of the temperature and humidity in ambient air. Some humidity and moisture instruments will automatically calculate dew point. Other humidity and moisture sensors readout on strip charts while more scientific equipment can datalog. c Single and multi-gas instruments will provide an immediate indication of the concentration of oxygen flammable and explosive gases and vapors. Other direct reading instruments measure certain aspects of indoor air quality and comfort levels.


Disaster Management

Trained companies and personnel whose job it is is to investigate and assess a building damage for an insurance company adjusting company city state or federal agency or a building owner. Disaster management companies may be asked to write an independent scope of work for the containment and control of the disaster. Quite often the disaster management company is retained to mitigate primary and secondary building structure building material and content damage including disaster recovery services. See Disaster Recovery


Disaster Recovery

Trained companies whose job includes the recovery of building and content damaged due to fires floods earthquakes tornadoes and hurricanes. Disaster recovery is meant as an emergency primary loss recovery method for the containment mitigation and damage control and relocation before secondary damage occurs. Prompt and immediate disaster recovery and relocation services are designed to save tens of thousands and sometimes millions of dollars in unnecessary property and content damage. See Business Loss Interruption


Disaster Relocation

The temporary relocation of homes and businesses by insurance companies and FEMA after an emergency. Included in disaster relocation is the need to inventory salvage recover restoration and relocation of undamaged and damaged contents computers software microfiche machinery office furniture and records. See Disaster Recovery


Disaster Repair

1 The temporary emergency repair or services necessary to stop reduce or eliminate a disaster occurrence or hazard. 2 Disaster repair is the repair and replacement of damage caused by a disaster. Mitigation Note In water damage remediation It is the removal of all standing water in a building and/or under a building. It is the custody care and control of all effected building materials and contents and reduction of further damage by technically trained employees. See Water Damage Industry Standards of Care


Disaster Response Time

In localities within a 25 mile radius it is the critical emergency response time usually within 1-2 hours from the time being notified which trained emergency response technicians are able to respond to a water fire or other types of property damage.



A legal or illegal method of disposing non-hazardous or regulated waste. Mitigation Note The most appropriate removal method of blackwater sewage from a building through mechanical means is discharging the waste back into the sewer system. In some communities this may be illegal since the waste must be contained and properly disposed. See Commercial Sewage Domestic Sewage Hospital Sewage


Disclaimer and General Release of Liability

In brief a written document that describes the methods that are to be used for the containment and removal of a contaminate and if the methods are not completely followed or allowed by the property owner you the contractor cannot be held liable for any claims resulting from partial contaminate removal or treatment. See your attorney for exact terminology.



A change in hue shade or colour from the original or adjacent colour.


Discontinuous Construction Wall

A method of construction whereby structural members are staggered to reduce sound between party and common walls or a floor.


Disinfectant Toxics

Disinfectants and detergents which leave irritant or toxic residues behind after application. They are harmful to the respiratory tract and they may harm humans and animals.



Chemicals that kill microorganisms. Commercial disinfectants are made of different chemicals and concentrations. Education Note All disinfectants after a disinfecting application in a building are to be rinsed flushed out. Safety and Caution Note Some chemicals disinfectants have pesticide in them they are not to be used in water damage mitigation on finished materials without the customers knowledge.



A deterioration crumbling or flaking of a material caused by oxidation pressure expansion freezing or exposure to the elements.



In indoor air quality the general term describing contaminates consisting of particulate matter suspended in air also the mixing and dilution of a contaminant in the ambient environment.


Dispute Resolution

When a dispute arises between the insured and insurance company a contractor or another third party dispute resolution is necessary to settle the differences between all the parties involved. The parties may decide to support their claims by retaining their own independent appraiser. Each party appraiser is an able and impartial appraiser and the plaintiff party must notify the defendant party of the appraiser name and qualifications within 20 days after a demand is received. The appraisers will then set the amount of loss based on their own assessment and calculations. If the appraisers cannot agree as to the amount of the loss and the work product necessary to complete the loss it may be agreed by the parties the appraisers themselves may choose an impartial umpire. If the parties cannot reach a settlement agreement through an umpire the parties will often agree to go forward with binding arbitration. See Binding Arbitration Mediation Mediation v. Arbitration


Do Not Enter

A posted sign at all entry and exit areas of a work area and areas which may have a hazard must have do not enter signs clearly posted. Education Note In water damage mitigation/remediation the Do Not Enter words should be pre-printed and several blank lines are to be added below the Do Not Enter for words that describe the reasons and potential hazards. Also a space for a signature and company information in case there are questions. Signs that have the date and time when the sign was posted the sign must have the date and time the sign is to be removed. See Confined Space


Document Drying

A restorative process by which wet humidified or contaminated documents have excess moisture removed. Education Note Document drying is typically accomplished through several processes including vacuum freeze-drying cryogenic freeze-drying and desiccant dehumidification. Properly completed document drying is effective on bound rare books general books and ledgers paper file documents blue prints drawings maps microfilm microfiche x-ray film photographs negatives aperture cards magnetic media audio/video tapes historical documents and some art work. See Thermaline


Document Reprocessors

The name of a U.S. company specializing in damage control and restoration of fine and historical documents that have become wet mouldy or smoke damaged throughout the world. Contact Document Reprocessors west coast office at 800/437-9464 east coast 888/437-9464 or www. documentreprocessors.com. See Thermaline



A word meant to describe the most appropriate method of removing personal protective equipment taking into consideration that it may be contaminated. See Donning


Domestic Hot Water

Hot water in supply pipes coming from a water heater as distinguished from hot water used in recirculating pipes for house heating.


Domestic Sewage

Residential sewage which was created in a residential community. It is the waste that flows out of residential toilets showers sinks tubs dishwashers and garbage disposal which are gravity carried away from the property to a sanitary sewer. See Commercial Sewage Hospital Sewage


Domestic Water

Any water that comes from a pipe for domestic use. Water which has been treated and made clean or is natural including pumped well water and in some situations recycled water.



A word meant to describe the putting on and wearing of appropriate personal protective equipment and respiratory protection. The wearer must take into consideration before they wear the PPE when it comes time to remove the safety equipment it may be contaminated and how are they planning to do this safely%u003F See Doffing



A state in which bacteria yeasts and fungi can suspend and live without much moisture. They become active again when available moisture or high humidity is present. Many organisms may die but those that live will thrive and develop their dormant inactive buds or cells once again.


Dormer Window

An upright window which breaks the surface of a sloping roof.


Dose response

An adverse effect on a biological agent or organism which causes a particular physical chemical response or change.


Dosimeter Dose Meter

An instrument used to determine the full-shift exposure a person has received to a physical hazard.


Double Bagging

A method of placing one bag into another of equal size and shape. Education Note Double bagging is a control and often a safety method for holding a contaminated item or substance. The intent of the double bag is to protect the user other employees and the work environment from a contaminate exposure. The exposure results from the outer layer or the inner layer being punctured having a leakage or breakage.



A movement or current of air. A draft is the pressure difference which causes a current of air or gases to flow through a flue chimney heater or space or to a localized effect caused by one or more factors of high air velocity low ambient temperature or direction of air flow. A draft is often described as a leak or break in insulation or a barrier having two different temperature properties.


Drag Wand

A drag wand refers to one of the earliest carpet cleaning and extraction tools used after the invention of carpet steam cleaning machines. Water Damage Mitigation Note A weighted carpet extraction wand extracts flood water deep out of a carpeted surface. Drag wands weigh from 35 pounds to up to 100 pounds. Newer style drag wands have wheels on the back side allowing for easier use of the drag tool. See Carpet Roller


Dri-Eaz Dehumidifiers

A manufacturer of quality dehumidifiers across the United States Canada and Europe. Dri-Eaz Corporation makes commercial size refrigerant and desiccant dehumidifiers that can remove large amounts of airborne moisture from a humidified atmosphere per day. See EBAC Phoenix Dehumidifiers Restorative Drying



A trademark name and process of the Dri-Eaz Corporation. The DriZone is a restorative drying method which Dri-Eaz says ...is a top-down drying process for wet carpets pad and certain building materials under clean water conditions. Education Note To understand the DriZone process Dri-Eaz teaches a hands-on class in a specially designed wet building environment in Burlington Washington.



In HVAC terminology a drop in air pressure or temperature is the vertical distance between the base of the outlet and the bottom of the air stream at the end of the horizontal throw.


Drum and Bin Liners

A 6-mm or greater plastic polyethylene insert sometimes they are manufacturer made to fit a specific container size and shape. Education Note Drum and bin liners are capable of holding liquids and solids to an amount which would fill at least 3/4 of the drum or bin as determined by the liner manufacturer. Drum and bin liners are made to hold specific liquids and depending on the liquid a certain type of liner may be called for.


Drums and Bins

Portable storage devises that are capable of holding a specific amount of waste.


Dry Air

The ambient air in a building atmosphere that is acceptable after dehumidification. Restorative Drying Note As it relates to water damaged buildings it is the indoor air and trapped air in wall cavities partitions cabinets under subfloors and in attics which has been returned back to its previous acceptable dry air state. As pointed out in Dri-Eaz Restorative Drying Manual dry air weighs about 14 pounds per cubic foot at sea level. In psychometrics dry air is used as a reference point. If the specific humidity of the air is 60 GPP then the air is holding 60 grains of moisture in each pound of air. See Dehumidification Grains of Moisture


Dry Bulb Temperature

The temperature registered by an ordinary thermometer. The dry bulb temperature represents the measure of sensible heat or the intensity of heat. The temperature of the air when measured for comparison with wet-bulb temperature. Most standard thermometer readings are the dry-bulb temperature.


Dry Bulb Temperature Adjusted

The average of the air temperature and the mean radiant temperature at a given location. The adjusted dry bulb temperature is approximately equivalent to operative temperature at air motionless than 80 fpm when the mean radiant temperature is less than 120%u00B0F


Dry Ice Blasting

The process using dry ice shavings and specially manufactured compressed air equipment to micro-finely disperse the dry ice onto a contaminated surface for removal of a contaminate. The results of the ice blasting provides for a clean surface while the dry ice residue disperses into harmless carbon dioxide gas. Depending on the application dry ice blasting can be as fine as debride and remove smoke and soot from a mural or painting or aggressive to remove char from wood. The dry-ice blasting or treatment residue is carbon monoxide gas. The carbon monoxide gas itself is not harmful to humans in open air environments. The use of dry-ice in confined space consumes the available oxygen and this condition must be avoided.


Drydown Process

The second phase of a building water damage after extraction and containment of flood waters which allows for wet building materials humidifies atmospheres and wet contents to start drying.


Drying Conditions

The ideal conditions after cleanup which allow a wet building to become ready for drying. Restorative Drying Note In water damage remediation it is the condition of the indoor air at any one time during the building drying process. The drying conditions of a wet building are influenced by the amount of standing water water vapour in air saturated water in wall cavities floors and contents condensed moisture vapour on other building materials and contents the relative humidity and temperature outside and the ambient humidity and temperature indoors. The building drying conditions must take into account the amount of water that flooded the building its source is the water considered contaminated the amount of porous building materials the amount of total moisture content in saturated building materials and contents. See Dehumidification Thermalgraphic Chart Recording


Dry-Rot Fungi

Dry rot fungi Merulius lacrymans flourishes under conditions of bad ventilation and high humidity. This fungi is more efficient at destroying wood than any other type of fungus predator. In a flourishing or proliferating stage it can attack wood which would normally be considered too dry to be attacked. Education Note Most persons feel that the presence of sun light and air alone may dry out a structure from saprophytic fungi which is not true. What also is not true when either wet rot or dry rot fungi dominate and attack a structure simple drying surfaces of building materials alone will not address underlying fungal issues. While wet rot fungi cannot penetrate brick stone or metal which does not have the aid of an airstream that can circumvent the other side of a wall dry rot fungi can penetrate or pass through walls in search of new wood to attack. See Wet-Rot Fungi



See Gypsum Board



The air supply and returns of metal or flex duct attached to a heating and air conditioning ventilation system. A passageway made of sheet metal or other suitable material not necessarily leak tight used for conveying air or other gas at low pressures.


Duct Liner Coating

A permanent adhesive painted-on coating in ventilation systems for unfaced fibreglass duct liner insulation metal vents drip and drain pans and sound board.


Duct Velocity

Air velocity through the duct cross section. When solid particulate material is present in the duct air stream the duct velocity must exceed the minimum transport velocity.


Due Diligence

A legal term describing a contractor or responsibly parties actions and their responsibility to address and reduce reasonably anticipated problems based on their agreement.


Dump Fees

Costs directly attributable to the job where land-fills and hauling contractors charge for the disposal of waste. See Waste Hauling and Disposal



Suspended solid particles in air which settle-out in buildings through doors windows and ventilation systems. An air suspension aerosol of particles of any solid material usually having a particle size less than 100 micrometersum. Education Note Natural dust includes organic and inorganic particles such as soil erosion by wind which entrains into a building and decaying organic matter and other airborne debris that feed bacteria fungi and yeast. Human dust created by the sloughing of dead skin cells that feed dust mites. See Respirable Dusts



Solid particles of organic debris including dirt and lint that are airborne and settle on surfaces through the influence of gravity.


Dust Collector

An air-cleaning devise that is designed to capture and remove heavy particulates from work areas before they enter outside air. A vacuum bag in a workshop capturing saw dust is an example of a dust collector.


Dust Collectors

Another name given to dirty ventilation systems drapes and carpets that are not maintained.


Dust Mites

Arthropods which use dead skin cells as a food source. Persons which allergies and who breathe mites can have allergic reactions to dust mites. Dust mites are often found in dirty building and specifically carpets. Dust mites multiply rapidly in high humidity.


Dust Spot Test

In HVAC metal ductsthe dust spot test is a measurement of the amount of settled dust on a ventilation duct surface. Education Note Dust spot tests are also used to determine the residual dusts after cleaning vacuuming the metal duct runs. The removal of surface dusts in a ventilation does not warrant the ducts are free of microbial influences. Only after cleaning followed by sanitization with an EPA registered disinfectant specially produced for ventilation systems should a duct be considered partially sanitized. Refer to NADCA 1992-01.


Dwell Time

The time necessary for a detergent disinfectant or sanitizer to work to its maximum potential.



In insurance terms dwelling means the attached and detached structures on the premises used principally as a private residence. See Coverage-A


Dynamic Pressure

Having to do with forced energy and motion also known as kinetic pressure or kinematics the study of motion without reference to forces. Education Note In water damage mitigation dynamic pressure is the bulk flow of forcing trapped moisture in building materials from a liquid to a vapor. Once dynamic pressure can be accomplished wet air in buildings should be exhausted and exfiltrated through removal or dehumidification. See Advection Exfiltration Static Air Turbidity Air Currents



A disorder of the gastrointestinal tract. The disease frequently results from infection from Shigella a disease transmitted from fecal contaminated water food and hand to mouth contact. Health and Safety Note Dysentery is common in sewage contaminations in buildings from black water flooding. See Cross-Contamination Fomites



A health condition resulting in a shortness of breath difficult laboured breathing.


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