MEC&F Expert Engineers : 09/05/15

Saturday, September 5, 2015

MISSING TANKER TRUCK CAP CAUSES LEAK OF ANYDROUS AMMONIA THAT SENDS ONE TRUCKER TO THE HOSPITAL IN OKLAHOMA




SEPTEMBER 4, 2015
By Cailey Dougherty

SAPULPA, Okla. —



Quick Facts:
  • Sapullpa fire responded to anhydrous ammonia leak near 49th West Avenue and West 61st Street Friday morning
  • Truck driver getting ready to get on his route noticed vapor cloud from the tanker
  • Investigators think someone took the cap from the tanker while he was gone, possibly to use the chemical to make meth
  • Man taken to the hospital for inhaling the chemical

Sapulpa fire fighters are investigating a chemical leak that hospitalized one man early Friday morning.

A truck driver was getting ready to start his route from a parking lot used by truck drivers when he noticed a chemical vapor coming from a truck.


He reported smelling a chemical and was sent to the hospital after feeling his chest tighten.

Sapulpa firefighters took precautions as they responded, stopping at a safe distance from the tanker.

They discovered the tanker was mostly empty. It had been carrying anhydrous ammonia, a gas commonly used in fertilizer. According to the Centers for Disease control, exposure to the gas can cause rapid dehydration.

There was enough left in the tanker to send the man to the hospital. The fire department discovered the cap on the tanker is missing, and Sapulpa police are investigating possible criminal activity.

ANOTHER BIOFUEL PLANT EXPLODES: 4 injured, 1 critically, at Renewable Energy Group in Geismar, Louisiana when hydrogen released from a line and exploded







SEPTEMBER 4, 2015
GEISMAR, LA (WAFB) -

Four people were injured, one of them severely, at the biofuel plant at Renewable Energy Group in Geismar, LA when hydrogen released from a pressurized line and exploded late Thursday night, according to the Ascension Parish Sheriff's Office.


The Geismar and Gonzales fire departments responded to the incident off LA 30 around 11 p.m. APSO reported the investigation revealed hydrogen likely pressurized in a line being worked on and resulted in the gas being released. Investigators added an unidentified source ignited the released hydrogen, causing the explosion and fire.

Deputies said one REG employee was severely injured. They added three contract workers were also injured. The Baton Rouge General Regional Burn Center reported one of the victims is listed in critical condition and another is listed in serious condition. Hospital officials said the third patient is listed in good condition, while the fourth was released.

The Ascension Parish Sheriff's Office posted the following information to Facebook:


Last night, Nick Matassa, son of Selma and Kenny Matassa, was badly burned in an industrial accident. He is currently undergoing treatment at a Baton Rouge hospital. Your prayers are needed for his recovery, and also please say a special prayer for three other workers who were also injured in this industrial accident. We at the APSO appreciate your thoughts and prayers.

REG officials issued the following statement Friday morning:


At approximately 12 a.m. central, a fire occurred at our Geismar biorefinery. Emergency crews quickly responded to contain the fire and it was declared completely extinguished at 4:20 a.m. All employees on site have been accounted for. Four people-one REG employee and three contractors-were injured and are being treated at Baton Rouge General Hospital. Our thoughts and prayers are with them and their families.
"It was an industrial fire, not a chemical release," said Rick Webre, director of the Ascension Parish Office of Homeland Security and Emergency Preparedness. "We want them to be assured that there was no impact to the public and no impact to the roadways around the facility."

Officials reported all operations have resumed at REG. They added the shelter in place orders put into effect at other plants as a precaution were all lifted early Friday morning.

"These facilities sit very close to one another at fenceline proximity, so a lot of times, there may be, out of just an abundance of caution or situational awareness, they may ask surrounding facilities, 'Hey, pay attention, just in case we need to let you know some information," Amy Johnson with APOHSEP said.

According to the company's website, the REG plant acquired the facility in 2014. It produces about 75 million gallons of renewable hydrocarbon diesel and renewable naphtha.

There was a previous fire at the REG plant on April 2.


The REG biofuel plant is converting natural fats, oils and greases into advanced biofuels and converting diverse feedstocks into renewable chemicals.


Some info about the REG company, obtained from their web pages:



Renewable Energy Group, Inc. is a leading North American advanced biofuels producer and developer of renewable chemicals. REG utilizes a nationwide production, distribution and logistics system as part of an integrated value chain model to focus on converting natural fats, oils and greases into advanced biofuels and converting diverse feedstocks into renewable chemicals. With 11 active biorefineries across the country, research and development capabilities and a diverse and growing intellectual property portfolio, REG is committed to being a long-term leader in bio-based fuels and chemicals.

For more than a decade, REG has been a reliable supplier of advanced biofuels which meet or exceed ASTM quality specifications. REG sells REG-9000™ biomass-based diesel to distributors so consumers can have cleaner burning fuels that help diversify the energy complex and increase energy security. REG-9000™ biomass-based diesel is distributed in most states in the US. REG also markets ultra-low sulfur diesel and heating oil in the northeastern and midwestern US.

About the REG Geismar, LLC Facility
  • Nameplate Capacity: 75 mmgy
  • Feedstocks: High and low free fatty acid feedstocks
  • Loading Capabilities: Feedstock inbound via Truck and rail; Fuel outbound via truck

Address:
36187 Hwy 30
Geismar, LA 70734

Shell Alaska has deployed a wide range of vessels in support of its 2015 exploratory drilling at the Burger Prospect in the Chukchi Sea off the northwest coast of Alaska.

Ship Photos of the Day – Shell’s Arctic Fleet



Shell Alaska has deployed a wide range of vessels in support of its 2015 exploratory drilling at the Burger Prospect in the Chukchi Sea off the northwest coast of Alaska. The fleet consists of two drilling rigs and 29 vessels, including anchor handlers, barges, ice management units, landing craft/crew boats, offshore supply vessels, oil spill response vessels, tankers and tugs. Here’s a look at some of those vessels:


Drilling Units
20760764889_0f2ab0ca96_k
Above: Polar Pioneer



20759464920_1216f1f61b_k Noble Discoverer



Anchor Handlers (AHTS)
20921298646_d2596ae07d_k Tor Viking II


20324855334_584896a025_k Aiviq
Not pictured: Ross Chouest



Barges
20759501620_8fbcdd9b3e_k Arctic Challenger carrying the Arctic Containment System, the first operational subsea dome oil collection and processing unit.



20954951461_292a6e61f7_k Klamath, an oil spill response barge, and its supporting tug Guardsman.
Not Pictured: Tuuq, American Trader, Arctic Endeavor



Ice Management Vessels
20921481916_2d586e32c9_k Fennica
Not pictured: Nordica



Landing Craft/Crew Boats
20759626688_d040217f6a_k Unalaq
Not Pictured: King-C



Offshore Supply
20921508196_dffcfdf871_k Harvey Sisuaq



20760677919_dd4b467c86_k Harvey Spirit
Not Pictured: Harvey Champion, Harvey Explorer, Harvey Supporter


Oil Spill Response
20760692799_3b9870a70f_k Nanuq


Tankers
20759462630_c6d26f8eb4_k Minerva Antarctica
Not Pictured: Marika


Tugs

20326470673_555502a59f_k Ocean Wind


20760945059_78ceee04ff_k Montana
Not Pictured: Benjamin Foss, Ocean Wave
All photos (c) Shell Alaska

HOW OLD IS THE WATER DAMAGE? USING FUNGI AS FORENSIC TOOLS IN WATER DAMAGE INVESTIGATIONS



HOW OLD IS THE WATER DAMAGE? USING FUNGI AS FORENSIC TOOLS IN WATER DAMAGE INVESTIGATIONS



https://sites.google.com/site/metropolitanforensics/how-old-is-the-water-damage-using-fungi-as-forensic-tools-in-water-damage-investigations 









How Old is this Water Damage?






One question we often receive is whether the water damage is sudden or accidental or whether can be attributed to a long-term event or a single past event. Another question we receive from building owners and insurers is what is the cause and origin of the mold and fungi growth in the building.






There are a number of ways that these questions can be answered. First of all, molds are fungi. Fungi can be used as forensic tools to determine the location of water intrusion into the building and to determine the history of water or fungi damage. This is more effectively done in conjunction with accompanying observations, such as the type of wood damage, the color and pattern of the damage, the extent and type of the fungal growth, the humidity levels, and so on.





Fungi and Mold Epidemic?





During the last twenty years or so we have seen an explosion in mold- and fungal-related building repairs and insurance claims. Current estimates show that replacement materials needed to repair damage caused by rot alone account for nearly 10 percent of the annual wood production in the United States. Our opinion is that the changes we had to make in construction materials (such as the invention of medium density fiberboard (MDF), particleboard and oriented strand board (OSB)), along with changes in building designs, construction methods and negligent construction and maintenance have led to such a phenomenon. 






Earlier structures built with wood such as red oak, chestnut, hickory, and other hardwoods as well as wood cut from the heartwood of softwood species did not evidence as much mold or wood-decaying fungal growth. Builders have had to replace these hardwoods with framing material made out of yellow pine, spruce, Douglas fir, aspen; they are also making use of the above-referenced engineered products that are made out of softwood, sawdust, nitrogen, etc. 

Mold can attack the sapwood and engineered-wood surface, including the paper of the drywall faces, but it has hard time living of the hardwood that is common in older buildings. 






In addition, newer designed homes implement more organic material than old homes. New homes use more insulation which can trap moisture behind walls. EIFS (fake stucco) is also prone to mold attack, especially when wet. 

Additionally, tight building structures and poorly monitored HVAC systems found in newer buildings have contributed to mold growth. Leaky HVAC produces mold and disperses it throughout a building via ventilation. 





The result is that, in combination with “more energy efficient designs”, today’s structures can more easily attacked by mold and wood decaying fungi. Even “small” modifications to the ventilation of a home can lead into major fungal outbreak. In a recent case, an insured had reduced his central air conditioning flow of air, resulting in reduced ventilation; this led to significant condensation and the growth of mold and fungi inside his home. The insured initially claimed that recent storms have caused the “water leaks”, but we conclusively established that it was simple condensation. The insured was asking for tens and tens of thousands of home repairs.





Most buildings have experienced some type of water intrusion: high humidity, leak, flooding, wind-driven rain, moisture intrusion from the crawl space or the sump pump, and so on. We often find mold growth in bathrooms, kitchens, basements and other high moisture areas. Careful inspection of buildings will usually find areas of fungal growth where the conditions are favorable: 

moisture, organic material, fungal spores and to a lesser extent temperature and light conditions. If all these factors are at play at a certain building for months or years, then there is high probability that a fungal growth has been developing over the long-term and it was not a sudden or brand-new growth. 

Often times, the lack of weather protection of the building components during construction has caused rapid degradation of the framing members even at subsequently moderate moisture levels.














Wood Decaying Fungi





Wood decay by fungi is typically classified into three types: soft rot, brown rot and white rot. Brown rot fungi are the most prevalent with regard to attack on coniferous, structural wood products in North America. The wood decayed by brown rot fungi is typically brown and crumbly and it is degraded via both non-enzymatic and enzymatic systems. Brown rots usually cause wood to lighten in color prior to becoming dark brown, and to crack along and across the grain. When dry, very decayed timber will crumble to dust.





White rot fungi are typically associated with hardwood decay and their wood decay patterns can take on different forms. White rotted wood normally has a bleached appearance and this may either occur uniformly, leaving the wood a spongy or stringy mass, or it may appear as a selective decay or a pocket rot. 

The fungi producing these rots can produce airborne spores and influence air quality. However, they are primarily of concern because of their capacity to destroy the structural integrity of wood.





The soft rot fungi can degrade all three of the structural wood components, although the major food sources are cellulose and hemicellulose. A wide variety of fungi can cause soft rot, including the ubiquitous Chaetomium. For soft rot to occur, liquid water must be continuously present. Wood with soft rot is spongy. The most common sites for soft rot in buildings are wooden windowsills and areas where roof drips continually wet wood materials.





White and brown rot fungi can form fruiting bodies on the surface of colonized wood, and can produce massive numbers of basidiospores. If basidiospores are higher indoors than out on air samples, the possibility of wood rot should be considered, and the type of basidiospores explored more carefully. 





Because water flows downward under the influence of gravity, looking at the uppermost area of rot could help determine the origin of the rot. The pattern of the rot is the best clue to the water entry mechanism. Figure 1, 2 and 3 present some examples of cases where we were able to use the knowledge of fungi growth to determine the timing of the water release.

























Figure 1: Mushroom of a brown rot fungus (a Basidiomycete) growing in the attic. This is just the fruiting body (the spore-producing body) of the fungus. There is a much larger fungal body inside the wood. This fungal growth and associated wood damage started in areas of the roof sheathing weakened by nail and other penetrations, took a lot time to develop and was not caused by a recent sudden or accidental moisture release. The recent storm did not cause the water damage.


























Figure 2: Fungi (Peziza domiciliana) growing on the basement exterior foundation wall and feeding on the organic and inorganic matter present on the wall. Note the mycelium (net-like structure). Constant moisture coming through the cement block or leaking pipes/equipment in the basement, to name a few causes, will increase the humidity in the building. This will in turn cause this fungal growth. 

By knowing the growth rate of Peziza, we determined that this fungal growth took several weeks to develop. Many homes in high moisture areas exhibit these types of growth that are not necessarily caused by a single sudden or accidental event.




















Figure 3. The wood above is not only moldy, a closer examination shows that it has rotted. The rotted condition of the wood indicates long-term exposure to water and makes it less likely that the mold on the wood is due only to the single recent leak event occurred few days prior to the inspection. 

In combination with other construction defects that we observed, we opined that faulty construction caused the rotted wood and mold and not the leaked pipe.




In many cases we see both dry desiccated fungal growth and more recent growth, suggesting multiple water damage events. Depending on the pattern of the fungal growth and the speciation, we may be able to distinguish between old and new water impacts.






Metropolitan Engineering, Consulting & Forensics (MECF)




Providing Competent, Expert and Objective Investigative Engineering and Consulting Services




P.O. Box 520




Tenafly, NJ 07670-0520




Tel.: (973) 897-8162




Fax: (973) 810-0440




E-mail: metroforensics@gmail.com




Web pages: https://sites.google.com/site/metropolitanenvironmental/










Metropolitan appreciates your business.




Feel free to recommend our services to your friends and colleagues.





We know you need to process damage claims quickly and knowing the facts is now faster than ever – within 24 hours of site visit. Our Pegasos Forensic Investigation Services (PFIS) feature:





· Expert Forensic Investigators on-site




· Defensible, Readable, Conclusive Reports




· Fixed-Prices starting at $499 per chimney or roof inspection (volume discounts are also available). Flood loss assessments start at $999.0.




· 10-State Coverage Area

APPORTIONMENT OF REMEDIATION COSTS USING FORENSIC METHODS

APPORTIONMENT OF REMEDIATION COSTS USING FORENSIC METHODS
https://sites.google.com/site/metropolitanforensics/apportionment-of-remediation-costs-using-forensic-methods
Many of Metropolitan’s clients ask our remediation experts to evaluate the appropriateness and cost of remediation decisions, estimate future liabilities, and apportion costs among potentially responsible parties.  Our experts rely on forensic methods developed in-house and/or widely used in practice, hands-on practical experience and knowledge of rigorous financial and engineering models to conduct such cost evaluations and cost apportionments.  Metropolitan scientists have been supporting clients in developing technically sound apportionment strategies and obtaining appropriate evidence for more than 30 years. This work has resulted in successful, quantitative apportionment of chemical inputs to CERCLA, RCRA and state sites as determined by the courts.


The common questions posed to us by the clients include:
·         What is the source of the contamination?
·         What are the characteristics of each source?
·         Who is responsible for each source?
·         What is my cost?

Metropolitan staff has been involved in numerous cases where liability and cost allocation are evaluated using strict review of the National Contingency Plan (NCP).  These cases arise from environmental cleanup and restoration project disputes under the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA), and also include natural resource damage (NRD) claims for restoration n costs. Projects have included commingled groundwater contaminant plumes, large river and urban bay projects with multiple contributing parties, waste landfills, mines, and other contaminated sites. This work has involved investigation of potentially responsible parties, historical site reconstruction, financial analyses, database development, and environmental forensics.
            In one recent case involving overlapping various petroleum product plumes (crude oil, naphtha, gasoline), we apportioned the remediation costs by identifying the constituents in the subsurface and the free product, identifying most likely sources, and apportioning responsibility based on the relative amounts of the contaminants at the site.  To that effect, we divided the site in contamination zones, reviewed existing TPH data, performed additional TPH analyses in each zone, and averaged crude oil, gasoline and naphtha percentages for each zone.  The cost apportionment was accepted by all the parties involved and settled the dispute.




Evaluation of Remedial Alternatives, REVIEW OF PAST EXPENSES AND ESTImation of Future Liabilities AND COSTS


People in control of the remediation process are often focused on a particular presumed remedy or on an overly conservative remedy.  Often in such cases, the cleanup costs could have been significantly less, yet sufficiently protective, if scientifically sound, risk-based methods had been used.  Metropolitan toxicologists and ecologists perform site-specific analyses to support the establishment of realistic cleanup goals, and to provide more appropriate comparisons of short-term and long-term human health and ecological risks for different remedial scenarios. 

Metropolitan has found that our thorough and objective evaluation of project risks and potential fatal flaws in site characterization and remedy selection provides a sound technical basis for advising our clients about cost-effective remedial solutions.  We have worked with our clients and the regulatory community to develop least-cost, effective alternatives that have been used to drive business decisions pertaining to Sarbanes-Oxley and bankruptcy requirements, while consistently receiving the approval of regulators.  We have assisted our clients with oversight of the development and evaluation of alternative remedial solutions, costs, and implementation scenarios that meet the capital demands of cash-limited businesses.  Metropolitan has no vested interest in the selected remedy, and thus, our scientists and engineers are technically unbiased and include thorough evaluation of site-specific constraints and potential impacts to onsite operations and nearby human and ecological receptors.  In predicting future liabilities, we use a variety of techniques, from probability-weighted decision-tree analyses to Monte Carlo stochastic models.

In a recent case, Metropolitan was retained by an industrial client to review the environmental costs claimed by the purchaser of its former facilities as damages under an environmental indemnification agreement established at the time of the sale.  As part of its analysis in this case Metropolitan reviewed technical documents, as well as, available financial information and costs.  Metropolitan was able to identify claimed expenses which were not reimbursable under the agreement, these costs included; routine business expenses, compliance costs and costs which pre-dated the agreement.  Metropolitan constructed a detailed spreadsheet which applied various liability allocations, recoveries from third-parties (including insurance recoveries) and calculated pre-judgment interest.


Metropolitan worked on this project for several years, first in the settlement context and ultimately testifying at a binding arbitration.  Metropolitan’s work on this project ultimately resulted in significant savings to the client.
SAMPLE PROJECTS
MTBE Cost Allocation Cases

Metropolitan was retained in a number of non-litigation and legal cases to allocate responsibility for petroleum releases at service stations leading to alleged contamination of residential wells.  Metropolitan provided alternative remedial cost estimates, performed stable isotope and other forensic analyses to determine the petroleum sources.


CERCLA Cost Recovery Case

Metropolitan was retained to provide expert opinions in a CERCLA cost recovery case involving soil and ground -water contamination at a former coal tar refining facility. Metropolitan provided opinions regarding the sources, extent and probable remedial costs for various contaminants, including both coal tar constituents and chlorinated solvents, and apportionment of responsibility for remedial costs between the current and former owners/operators of the site. Metropolitan was able to demonstrate that our Client’s contribution to the documented soil contamination was substantially less than claimed by the plaintiff. In addition an evaluation of probable future cleanup costs indicated our Client’s share of the total projected cost was substantially less than claimed.  The Court found favorably for our client.

Objective Review of Environmental Claims

Metropolitan was retained by an insurer client and an insured industrial client, to assist them settling a claim for environmental liabilities.  Our two clients requested that we provide a fair and balanced estimate of past and future environmental costs at several industrial plants. Metropolitan performed site visits, reviewed records at company headquarters and at state regulatory offices, and developed site-specific environmental estimates to complete site clean-up to risk based standards.

Within four months of being retained, Metropolitan was successful in assisting the two clients in reaching an amicable settlement regarding the amount of environmental costs.  By using Metropolitan as an objective technical resource, both parties saved significant in litigation costs and duplicative consulting costs, and a settlement was reached much sooner because both parties were starting from the same environmental cost estimate.

Cost Allocation for PAH Contamination
            Metropolitan was retained by an insurer to review and critique the allocation method proposed by consultants for the site owner.  Metropolitan also provided our own allocation method, based on synthesizing site-specific historical information regarding equipment, housekeeping, tar production, and changes in feedstock, as well as analyzing present-day contamination patterns.  The claim was amicably settled by both parties using the allocation method proposed by Metropolitan.
Remedial Options for Sediment Contaminated with PCBs
            Metropolitan was retained by an industrial client to review and evaluate potential feasibility study remedial options for sediment PCB cleanup, their cost, and risk of implementation.  The work included detailed evaluation of costs beyond the standard feasibility study analysis of –30 to +50 percent.



Metropolitan’s Pledge
Our goal is to help you resolve the claim at the lowest possible transaction cost.  Since transaction costs are, on average, fifty to seventy five percent of the claim, Metropolitan believes that the emphasis should be placed in reducing the transaction costs by collecting high quality data early on to ensure unnecessary challenges by the insured and/or other insurance carrier, should the claim is subrogated. 
We know that you want the facts; that you want them fast; that you want uncompromised quality of the deliverable; and at a rock bottom price.  Metropolitan’s forensic professionals are second to none and are dedicated to fast, efficient and effective response and creating a product of uncompromising quality and value. 
Metropolitan is ready to assist you with a number of forensic engineering or age-dating determinations or evaluations to insure that the proper coverage trigger or period has been determined.  We also have the scientific expertise to determine whether the releases were historic in nature, whether they were sudden or accidental, as well as to be able to differentiate plume contributions from various sources.
We are ready to assist you with E&O claims and/or construction defect claims.  Metropolitan will also use proven forensic techniques in the determination of the cause, origin, and extent of foundation/soil movement, grating/drainage, structural failures, water intrusions, construction defects and other failures. 

Our job is to find out what happened and why, from the cause and origin through the extent of loss.  Metropolitan will be able to point the way toward a speedy disposition of the claim.

Metropolitan Engineering, Consulting & Forensics (MECF)
Providing Competent, Expert and Objective Investigative Engineering and Consulting Services
P.O. Box 520
Tenafly, NJ 07670-0520
Tel.: (973) 897-8162
Fax: (973) 810-0440

Metropolitan appreciates your business.
Feel free to recommend our services to your friends and colleagues.
We know you need to process damage claims quickly and knowing the facts is now faster than ever – within 24 hours of site visit.  Our Pegasos Forensic Investigation Services (PFIS) feature:

·         Expert Forensic Investigators on-site.

·         Defensible, Readable, Conclusive Reports.

·         Fixed-Prices starting at $499 per chimney or roof inspection (volume discounts are also available).  Flood loss assessments start at $999.0.  HVAC equipment only inspections start at $299 for local (within one hour one-way drive) assignments.

·         10-State Coverage Area.

·         All of our employees and associates are subjected to full FBI background investigations and security clearance.

CAUSE AND ORIGIN INVESTIGATION OF BOWSTRING TRUSS ROOF FAILURE

CAUSE AND ORIGIN INVESTIGATION OF BOWSTRING TRUSS ROOF FAILURE

https://sites.google.com/site/metropolitanforensics/cause-and-origin-c-o-of-bowstring-truss-roof-and-other-structural-failures

 








Many roofs constructed of wood bowstring trusses have failed this winter.  This type of roof is historically prone to failure.  They were very popular in the 1940-1960 time periods because it gave the owners the ability to build attractive structures with open floor spaces and no load bearing columns.  A lot of warehouses and hangers still have these wooden bowstring trusses. 



Unfortunately, there are many reasons why these trusses fail.  Based on our inspections of failed truss roofs, we can say that one of the most common reasons for failure is the deterioration of the truss ends where it is mounted on the load bearing wall.



In the course of an investigation of a recent bowstring truss roof failure we made the following pertinent observations:



  • Inspections found water stains along the left and right masonry walls.  Inspections also found deteriorated mortar joints on these walls and in particular the failed left masonry wall; the significant long-term water staining to the left foundation wall, as well as the degradation of the wall components, is consistent with long-term chronic water infiltration into the wall structure originating from the roof area above.  Based on the conditions to the masonry wall components, it is not unreasonable to believe that the roof was leaking at the bearing point above over an extended period of time, which would have caused rot and deterioration to the roof framing at this location.



  • Inspections of the left masonry wall did not find signs of adequate roof drainage; inspection found no roof drain(s) to be located at the left side of the building;  a roof drain was found to be located on the right side of the building; that drain was found to discharge a small amount of water;



  • Inspections found that the top wall plate (or sill or ledger as is otherwise known) along the left exterior masonry wall was either rotted or had long term decay or water damage;



  • Inspections found that the top chord was connected to the bottom chord using bolted split-ring connections;  this assembly was then toe-nailed to the top wall plate;



  • Inspections found that the top plate at the left wall was not made of pressure treated wood and that a moisture barrier had not been provided;  the top plate was anchored to the concrete block wall using anchor bolts;  inspections found that a moisture barrier was not provided at the right exterior masonry wall;



  • Inspections found many truss ends, top wall plates and other roofing material that were severely rotted from long-term roof leakage. 



Why the Bowstring Truss Failed

The end connections on these bowstring trusses were critical to the overall truss performance.  The bolted, split-ring end connections at these locations transfer large thrust loads from the top chord members into the bottom chord.  As a result of the long-term moisture and water impacts, rot and decay caused the wood to soften and lose strength, resulting in localized sagging of the bottom chord, and elongation or splitting of the end bolted split-ring holes.  We observed many truss ends that were rotted or decayed and where one of the truss members (either the top or the bottom chord) had separated from the split-ring connection.



Long-term deterioration of these truss ends resulted in failure of these connections and consequent loss of truss action.  When the end connections deteriorated or failed, the outward thrust from the top chord (that is under compression) when the truss is properly functioning, was no longer resisted by the bottom chord.  Instead, thrust loads pushed outward against the supporting masonry walls, resulting in bowing of the walls and, since were left unchecked, resulted in complete failure of the roof. 



Some deterioration to the joints of the masonry walls was found.  Also pre-existing repairs to the roof trusses were found consistent with prior knowledge of distress to the roof structure.  The above conditions clearly document that the roof structure has been subjected to chronic water infiltration resulting in degradation to the framing components causing a loss of structural capacity.  Therefore the root cause of the failure is attributed to long-term deterioration to the roof structure rather than the weight of ice and snow.  Although the weight of ice and snow on the roof was part of the loading that caused the roof to fail it cannot be considered the root cause of the roof failure.



Other Structural Failures

Metropolitan services range from determining the cause and origin (C&O) to evaluating the damage extent due to the snow load or tree fall.  Construction defects are commonly faulted when failures occur.  Frequently Metropolitan finds design defect, construction defects and decay as contributing causes of a failures.

Metropolitan is often asked to assess historical structures.  Often, remodeling that occurred decades earlier begin to show deformations and structural responses.  A recent claim involved a home where ten years ago a property owner wanted to create an “open space feeling”.  The architect then decided to remove a load bearing wall to create the open space and designed a flush flitch beam to take the load.  Metropolitan discovered that the flitch beam was not properly supported on both ends by a load bearing wall and was instead supported at one end by the weakened wall!  That is a major blunder folks.  The punishing winter we are having is stressing the structures to the point that these design defects are now showing up.



It is Metropolitan’s experience that there is no substitute for a thorough and comprehensive inspection of the structures to determine the number of conditions that caused the loss and whether the conditions worked independently, concurrently, or in a sequence to cause the damage. 

A comprehensive investigation is crucial to good claims handling.  Our clients require prompt and thorough claims investigation and fact finding and Metropolitan delivers high quality services at a highly competitive price. 

We are here to serve you 24/7.  Give us a call or email.




METROPOLITAN PROFESSIONAL ENGINEERING AND FORENSIC SERVICES

P.O. Box 520

Tenafly, NJ 07670-0520
Tel.:  (973) 897-8162
Fax:  (973) 810-0440
E-mail: metroforensics@gmail.com