a family owned company founded in 1947, provides full-service Forensic Engineering and Fire Investigation Services
. For over 60 years, Donan Engineering has been providing unbiased answers to their client’s complicated questions. Their team of licensed and experienced forensic experts provides investigative services in the fields of engineering investigations, fire and explosion origin & cause, roofing investigations, and component testing. The diversity of their multidisciplinary staff allows them to provide not only a complete service, but a complete service whose conclusions can be successfully and completely supported.
Donan Engineering has become a richly diverse, industry leader with over 250 employees operating from 50 offices in 27 states including Alabama, Arkansas, Florida, Indiana, Illinois, Iowa, Kansas, Kentucky, Maryland, Massachusetts, Michigan, Mississippi, Minnesota, Missouri, Nebraska, Ohio, Tennessee, Wisconsin, Georgia, North Carolina, South Carolina, Pennsylvania, Louisiana, Texas, West Virginia, Virginia, and Oklahoma. Throughout their growth, Donan has maintained their commitment to providing exceptional customer service, unparalleled quality, unmatched integrity, and timely reporting. Most importantly, they pride ourselves on delivering their clients quality services at an affordable price.
|BridgesFoundations and BasementsGeotechnical / Sink HolesLightningLow and High VoltageMechanical SystemsRetaining Walls||Steel ConstructionTrussesVehicle Mechanical StudiesVibrations: Earthquakes and BlastingsWater Infiltration / MoldWood Frame Construction|
Fire / Explosion Origin and CauseCommercial FiresEquipment FiresVehicle / Residential Fires
Roofing InvestigationsCommercialResidential - Asphalt ShingleResidential - Slate, Tile, Etc.
|Heavy TrucksMotorcycles||Passenger Vehicles|
By far the most common water heater type found in American residential housing is a gas or electrically heated storage tank type. These are relatively simple appliances and generally operate successfully day-in and day-out with little maintenance or thought. However, like any appliance, they eventually fail and often an engineer is needed to explain why.
A fire investigation at the end of a long day was a perfect illustration of staying open to potential causes, and, a reminder that sometimes discovering the origin and cause of a fire is a life-saving endeavor when it prevents future dangers.
Does this sound familiar? The chimney is leaning and separating from the house. You observe separation between the chimney and the house that increases in width with height (i.e., there is no separation at the bottom and there is upwards of 2 inches of separation at the roofline) (Figure 1). The heavy self-weight of the chimney comprised of masonry components is prone to rotating away from the house due to settlement of the underlying soils. Further, due to the height of the chimney, a relatively small rotation of the chimney foundation could result in a significant separation toward the top of the chimney. Most commonly and rightfully so, the cause of the chimney displacement is settlement of the underlying soils supporting the chimney foundation.
Commonly called "flat roofs," most commercial buildings are actually clad with roof systems that provide about 1/8 to ¼ inch per foot of positive drainage. These roof systems are constructed differently than most steep-slope roof coverings and are typically watertight rather than water-shedding assemblies.
A recent Donan forensic fire investigation found that a poor connection in a floor-mounted duplex receptacle was the cause of fire. The receptacle was located in the area of origin and all other identifiable causes were eliminated during the investigation. While conducting the research for this particular case, Donan investigators evaluated many scholarly sources in order to clearly educate the client on how a loose connection in a receptacle could lead to a structure fire which, in this case, nearly consumed the bedroom. The best explanation was found in the chemistry associated with the formation of an oxide that contributes to the condition.
Over the past several years, there has been a clear trend of phasing out "dry-charge" air conditioners and heat pumps. What happened, why are some contractors still selling them, and what are the current common repair/replace options? Read this insightful article for everything you need to know on the topic.
The term plumbing is derived from the Latin word "plumbum," the name of the metal lead that was the preferred material used by the Romans to construct their empire's water supply systems. This bit of history is even relevant today as the continued use of this potentially toxic metal has made headlines because of recently exposed problems in the Flint, Mich., water supply.
Most forensic investigation projects include a scope to determine the cause of some damage or condition. Project scopes often request determining the cause and origin of the damage. Since insurance policies contain descriptions of covered and non-covered situations, clearly specifying causes and origins is crucial for clients' coverage decisions. This article discusses the differences between and significance of these two important terms.
Brick masonry chimneys have been prevalent for centuries, but it wasnt until recent decades that brick-clad, wood-framed chimneys became common in residential construction. This trend resulted from the increasing popularity of metal insert fireplaces. While they may appear similar from the exterior, the structure and weather-resistant envelope of wood-framed chimneys are very different than masonry-built chimneys. Prior to studying damage, it is important to understand critical elements in the structural support and weather-resistant envelope of wood-framed chimneys and the types of damage that can result from improper construction.
Fires can be caused by devices that fail due to a manufacturer's defect. Quality assurance procedures have gone a long way to eliminate out-of-box failures but manufacturers sometimes bypass quality checks on consumer products for competitive reasons. Even the most ethical companies are susceptible to human error that can cause an almost imperceptible change in an otherwise flawless manufacturing procedure.
As the days get shorter and temperatures turn milder, most HVAC systems are taking a well-earned vacation. For a short while, a cool breeze through open windows will be enough to keep us comfortable in our homes. But soon, homeowners will switch their thermostats from cooling mode to heating mode, and some of them will unfortunately discover their HVAC system does not heat. It's time to pull out those extra blankets and make the call to a service professional sooner than expected.
Wood bowstring trusses were used extensively in commercial buildings from the 1920s to the 1960s. Wood bowstring roof trusses provided long clear spans necessary in warehouse and industrial buildings. Many roofs supported by bowstring trusses are still in service today. Compared with other structural timber-truss types, bowstring trusses have exhibited more frequent structural problems. The structural deficiencies encountered are attributable to deficiencies in the original design of the trusses combined with damage due to exposure and age.
The National Fire Protection Association (NFPA) has released a 2015 edition of NFPA 70E: Standard for Electrical Safety in the Workplace. It covers and assists in complying with the Occupational Safety and Health Association's requirements, including changes to requirements since the last edition. For personal safety in forensic studies it is important to stay informed of these updates. NFPA 70E covers arc flash risk assessment, establishment of arc flash boundaries, requirements of Personal Protective Equipment (PPE), use of PPE within the arc flash boundary, and equipment labeling requirements regarding arc flash hazards. The following examples illustrate the importance of staying abreast of the latest standards.
History shows us that building codes have been around for a long time - in fact, the earliest known was around in 2000BC. Penalties were also much harsher for construction defects. If a builder constructed a house that collapsed and killed the owner, the builder was not fined, but was put to death. The United States has been a country with diverse codes - as many as 5,000 at one time. More recently, however, various states and municipalities have adopted "model" codes such as the International Building Code or International Residential Code. These provide a "base" and may be used as written or an Authority Having Jurisdiction (AHJ) may amend certain parts of the model code, making it more stringent and/or specific for a certain area.
Whether it is helping us formulate our opinion or confirming an initial diagnosis, technology plays a valuable role in forensic engineering work. Following are a few examples of existing technology available to Donan's project managers. Though not standard issue, these tools are utilized when necessary to accurately determine or confirm a cause of loss.
There are many types, manufacturers, and sizes of commercial HVAC systems which can make it difficult to create general guidelines for repair procedures and estimates for hail-damaged units. This guide uses the most common "light commercial" rooftop units (RTUs), which are 5-tons, 7.5-tons, and 10-tons in capacity, for estimating time to repair or replace.
Imagine for a moment that you are sitting in your home, listening to the rain while reading your favorite novel. Then suddenly you hear a roar of thunder and your home becomes dark. What just happened? You may have just experienced a power surge. Although lightning is not the most common cause of this phenomenon, it is excellent for illustrating what a power surge is and how it can affect your home. A power surge is a term used to describe a condition where the voltage and or current increases beyond its normal levels. Power surges, when due to the elevation of the voltage being supplied by the electrical utility company, have the potential to change data streams, interrupt electrical control circuits, burn out components, cause arcs, create shorts between conductors, overload systems, and cause system failures. The most common causes of power surges are indicated as follows:
Concrete is a desirable construction material due to its inherent strength and durability, which make it well-suited for many applications in residential and commercial construction, especially foundations, floor slabs, driveways, sidewalks, and roads, among other things. In these applications, concrete that is properly designed, mixed, placed, and maintained will perform exceptionally well for many years. However, poor design or mix, improper placement, finishing techniques, or inadequate maintenance may result in concrete that does not perform as intended. Aside from cracking, which is probably the most common form of distress to concrete, since virtually all concrete will crack as it cures, surface distress due to scaling, spalling, and popouts are the most common forms of damage.
The relationship between wind, hailstone velocity, and impact energy is based on an understanding of fundamental physics. Over a half century of laboratory research and field studies have determined that the severity of hail damage to a roofing material is contingent on the kinetic energy at the point of impact and the roofing material's resistance to that impact energy. These studies have found that a hailstone must be of a certain mass (i.e., size), and it must be traveling at a certain speed (velocity) to result in functional damage to the roofing material. The kinetic energy is a composition of mass and velocity, defined by the following equation:
Chances are, it's happened to you. An unexpected period of cold weather occurs and temperatures drop well below freezing for an extended period of time. One morning you attempt to turn the water on in the kitchen sink and...nothing. Hot water? Nope. Cold water? Nope. What happened? Did you forget to pay the water bill...again? Chances are, your pipes are frozen. "How can that happen? They are inside the house!", you may say; however, just because your water lines are inside the building envelope, does not mean they are adequately protected from freezing.
If hail impacts a roof covering and the effects of this impact result in some loss in the material's overall integrity or functionality, this material is classified as "hail damaged." More specifically for cedar shakes and shingles, valid hail damage is typically a new fracture of the cedar corresponding to a clean spot or scuff mark from the hailstone impact.
Although sags along roof ridgelines can be discovered at any time, in northern climates they are often attributed to the effects of a past snow load. To make an educated analysis of the actual cause of this phenomenon, one must have a basic understanding of the structure and the loads to which it has been subjected.
Heating, ventilating, and air conditioning (HVAC) systems consist of many components that work in unison to create the desired comfort level for our homes and offices. A well maintained system is designed to last around 15 years, but the life can be dramatically reduced when proper installation procedures and routine maintenance are not performed.
Ice dams and their resultant leaks are often a chronic and expensive problem in those regions where snow-covered roofs are a common occurrence. To understand their detection, cause, and prevention requires some understanding of the dynamics of a structure's construction, insulation, and ventilation.
A space heater is a device designed to warm a small area. These devices are typically portable, but the category does include gas- and wood-fueled models that are permanently installed; however, these are not the focus of this article.
Washing machine failures can create significant damage, exposing insurers and their clients to property damage. These failures often involve a high volume of water and can occur without warning. Through the examination of several hundred washing machines, the DONAN Component Testing Laboratory has identified a statistically significant failure trend in General Electric (GE) washing machines. The amount of water supplied to the tub of the washing machine is controlled by a water valve (solenoid-controlled valve) and pneumatic controls. The washing machine's load selector is a pneumatic pressure switch, which activates and deactivates the water valve.
Shallow foundations are the most commonly designed and constructed structural foundation system. As opposed to deep foundations where structural loads are transferred to subsurface layers or multiple depth ranges, shallow foundations transfer loads to the earth (soil) relatively near to the ground surface. Some examples of shallow foundations include building components often seen in residential construction such as spread footings, continuous foundation walls and footings, slab-on-grade foundations, and mat-slab foundations.
After a tornado event, devastation and destruction are found along the tornado path. Due to the wood-framed construction predominant in Texas and Oklahoma, extensive damage to a house can occur. But how do you know whether visible cracks in the Sheetrock or brick finishes are just cosmetic damage or the signs of structural failure?
Automatic fire suppression systems are by far the most effective and safest means of preventing extensive fire damage and saving lives. For this discussion, we will touch on automatic sprinkler systems (building systems) and kitchen hood suppression systems. These systems range from very simple to extremely complex.
Summertime rolls around and people start seeing condensation on ductwork. Their first thought is that something is wrong with their air conditioner. Actually, sweating ducts have several causes. Very few are attributable to defective air conditioners.
In urban and suburban areas, stormwater systems are found everywhere. From surface waterways, such as rivers, streams, and ditches, to subsurface drainage systems, such as storm sewers and culverts, stormwater systems are as ubiquitous as concrete, which is one of the reasons they are so important (Figure 1). Impervious surfaces like concrete, pavement, and roofs prevent stormwater from naturally absorbing into the ground, and the resulting runoff can cause flooding, erosion, and subsequent structural damage.
For many years, the fire investigation industry has seen numerous fires involving livestock buildings. These fires are often high profile, especially when masses of animals are lost or injured. Many times these losses are in older structures with neglected electrical and/or heating systems. Given the interior environment, corrosion and degradation to electrical and heating components are common.
Cupping, buckling, and crowning are three common problems encountered in wood flooring (flooring). These problems are caused by a combination of the normal material characteristics of the flooring and improper installation of the flooring.
While shovels, snowblowers, plows, and deicing agents are used to clear snow and ice from driveways and sidewalks during the winter, removing frozen precipitation from the roof of a house is a bit more challenging. As snow and ice piles up on the roof and subsequently thaws out, the melt-water can sometimes result in damage to the interior of the structure.
"Hail has damaged my concrete driveway!" How many times have you heard this claim? A homeowner whose house has experienced a recent severe hailstorm starts to notice things they never noticed before around their house.
A Donan fire investigator uses many techniques in order to determine the origin and cause of a fire. Chief among these are the investigator's observations of the scene and the conditions surrounding the scene.
In this age of high energy costs, the price of heating the house will increase. People will be searching for alternate sources to heat their houses.
In our October 2010 newsletter, Bob Whelan, P.E., discussed how to approach a roof hail study by using the scientific method. In summary, one should perform a collateral study of the property, or neighboring properties, to gather information about the particular hailstorm in question.
Whether to build a residence on a concrete slab or conventional crawlspace foundation is a common decision homeowners must make.
Is construction vibration just an annoyance, or does it have the potential to cause aesthetic and structural damage to nearby structures?
Attic ventilation problems can cause elevated relative humidity in an unheated, residential attic. Elevated relative humidity in the attic can promote mold growth and increase the moisture content in the wood framing to a level that promotes fungal growth and rotting.
Every year, Donan Engineering is asked to look at dozens of basement walls that have failed. A wall is determined to have "failed" when the structural integrity is compromised - such as with the development of a horizontal or vertical crack.