Tornado Damage Is Often Subtle But Significant, According to HAAG Engineering
The recent rash of tornado catastrophes across the country has left a path of obvious destruction. This is an example of the obvious damage:
What about structures that were not completely destroyed and those next to the most obvious destruction that remained standing? Did they escape the high winds and pressures without any damage?
A noted insurance company expert, Tim Marshall of HAAG Engineering, wrote a paper, Building Damage Issues in Tornadoes, which warns adjusters and policyholders to carefully inspect structures close to the tornado path for subtle but significant windstorm damages:
The assessment of property damage begins immediately after a tornado. Homeowners, insurance adjusters, contractors, engineers, and architects examine buildings and their surroundings to determine the extent of tornado damage. While catastrophic damage is easy to recognize, the more subtle signs of building distress are not.
The ever vigilant expert for insurers, Marshal notes that "inspectors often erroneously link these conditions to the storm." My impression is that most inspectors fail to look for these subtle tornado damages which add up to sizable losses because they fail to do an adequate inspection, if any inspection at all.
Nevertheless, Marshall provides a good description of how high winds impact structures:
Tornadic winds encountering a building are deflected over and around it. Positive (inward) pressures are applied to the windward walls and try to push the building off its foundation. Therefore, it is important that the building be anchored properly to its foundation to resist these lateral forces. Negative (outward) pressures are applied to the side and leeward walls.
The resulting "suction" forces tend to peel away siding. Negative (uplift) pressures affect the roof especially along windward eaves, roof corners, and leeward ridges. These forces try to uplift and remove the roof covering.
The roof is particularly susceptible to wind damage since it is the highest building component above the ground. Wind pressures on a building are not uniform but increase with height above the ground.
I have found that the important aspect of damage caused by these winds is the fastening system of the structure. Nails, clips, joints, brick ties and other assorted connections tend to get pulled, bent, cracked or weakened by tornadic winds and pressure. These damages are often difficult to find and, once eventually discovered, can be expensive to repair. Buildings suffering these damages will age, deteriorate and increase maintenance costs at much faster rates than buildings not damaged by tornadoes.
Adjusters should retain honest and unbiased investigators to look for these subtle but significant damages. "Drive by" adjusting, without close inspection and possible testing, is improper for structures in the vicinity of a tornado’s destructive path. While the Marshall article tends to provide possible explanations why these damages may be related to perils other than windstorm, educated policyholders will ask their insurer to investigate for these serious damages.
Excellent assessment! Should be a must-read for entire Construction Industry and associate industries, Government, etc.
Continuous Frame Reinforcing (see attached website) is the best way to counter lateral and uplift wind and seismic forces on buildings and structures, fyi. These are the newest development in Structural Reinforcing Systems.
Chip,
It easy for the carriers purported experts to overlook damage directly after a storm. They know that in most instances the Insured cannot afford to have their Property evaluated by Professionals who would certainly be more dilligent then the carriers Inspectors. Subtle damage is very easy to identify if you know what your looking for.
Hopefully with Firms like yours leading the way, Property owners will stop being intimidated by the Insurance Companies.
I just suffered through a massive tornado on 4/27/2011, in Pickens County GA.
My Insurance Company assigned my claim to an independent adjuster (I am not naming names "yet") the independent came out on 4/29/2011. He could not tell if structure damaged by looking around nor could he tell by using his new digital "toy" that needed a tripod, so my husband picked up our sprinkler that had been up in the tree, and propped it on that tripod. He got a reading he was unsure of so he assigned a structural engineer.
The Engineer (im not naming names yet) who was obviously representing the Carrier, came out on Sunday 4/30/2011. He stomped around, never introduced himself to me and I never received a business card, nor a report. Now we are into 5/13/2011, I have absolutely nothing except a conversation with the Independent who stated the engineer said no structural damge, house was built that way.
I have not received a written report from the engineer, or anything else except a sworn statement in proof of loss request from the carrier.
My house has not suffered any structural damage that "it was built that way" Well it was not that way "right before the storm" so I find it hard to beleive that "it was built that way"
I wonder what the Carrier will say when they hear this story.
OOOPS !!!