Some flood insurance claims are cut and dried. But in other cases, the cause of the damage isn't immediately obvious. The question of whether a claim is covered or not can turn on the nature of whether and how the storm caused the damage. Some situations call for an expert — somebody like Portsmouth, New Hampshire, structural engineer Anthony Coviello, of Summit Engineering.

Coastal Connection talked with Tony Coviello last week, after he returned from a three-day trip investigating flood claims on the south shore of Long Island in New York. Coviello couldn't discuss specific claims, but he had interesting things to say about the many ways flooding in Superstorm Sandy affected buildings.

In simple cases, extreme damage is "kind of obvious," says Coviello. "Your house is gone, here's a check, you're done." Minor damage can be less clear, he says. "Cracks in a home have been harder to ferret out. Sometimes people have cracks in their house and they don't notice—there is nothing to draw their attention to them. But then there is an event, an earthquake or a storm or something, and they walk into a room and they see a crack and say, 'Well, that crack wasn't there before,' and it may or may not have been. And so it's our job to try and determine: Were these pre-existing cracks? And were they caused by flooding or wind?"


Coviello says Sandy's flooding did cause some foundation damage. "What I personally have observed," he says, "is not necessarily the velocity of a moving wall of water causing damage. But the water comes in and floods the area and inundates the soil. The soil had a certain level of pre-existing compaction that they built up on. And when the water comes in, there is a little bit of a buoyancy force there that lifts the pressure up off the soil a little bit, and then when the water recedes, the soil particles stack in a more efficient manner than they were before. So we get what they call "re-densification" or further densification of soil. And that's not uniform. So you get one corner of your house where the soil is densified further, and then that settles, and it causes cracks in the slab-on-grade house."

"Most of the houses that I observed have had crawlspaces," says Coviello. "It's an unreinforced concrete masonry perimeter foundation wall, with floor joists and masonry piers with beams, and portions of those walls or piers settle, say, half an inch to an inch, or a couple inches in some extreme cases, and that settlement has caused cracks in the gypsum, and uneven floors, and issues like that."


The flood also created some examples of "scouring," says Coviello, where moving water removed soil and undermined a foundation. "It's very local," he explains. "You could have one house that is six inches lower than the rest of the neighborhood. A passer-by would say that the neighborhood is flat and everything is the same elevation. But water will tell you where the lowest point is. And if you are draining an entire neighborhood, many acres draining through one property, you're going to start picking up some water velocity—not from the inundation, but from the water leaving the site. The lowest point of a house is typically the foundation, and if water is traveling by your foundation—six acres of water is trying to leave through a little ravine that is next to your foundation—you are going to get some scouring. That's going to eat away the foundation. So, we've seen some minor examples of scour, and we've seen redensification. But I don't think we've seen them both at the same location—we've seen one or the other."

Tight vs. Leaky Houses

In some cases, says Coviello, newer homes paradoxically suffered worse damage than older homes—because they were more tightly built. "My business partner has seen examples of houses where they are really buttoned up well, and the water doesn't leak into the house—so you've got a differential height of water," he explains. "And even though the water is not moving very fast, you'll get four feet of water outside and no water in your house. Now your little 2x4 stud walls are trying to hold back four feet of water, and it's buckling and cracking the walls, so there is that type of damage. But a leaky house that let the water in, it never had unequal levels of water from inside to outside, and much less damage occurred."

Flood insurance adjusters typically only consider damage to parts of the house that actually got wet. But Coviello says some structural damage caused by water can lead to damage in dry upper floors. In one case, he says, structural movement apparently damaged a second-story plaster ceiling. "A lot of the floor shifted below, but their first floor ceiling happened to be mostly wood paneling, and a little bit of movement was able to be absorbed by the paneling without really much indication to the casual observer," he explains. "But you go up to the second floor where everything is plaster, very brittle — and there are spider-web cracks everywhere."

Repair vs. Improve

Besides identifying damage, and providing an opinion about its likely cause, Coviello and his partner also weigh in on repair choices. "We don't give the adjusters a construction estimate," he says. "But they are trying to assign a number to our report. So they ask us specific questions: 'Can it be repaired? If it's a loss, what percentage of loss?' So we might say, 'Yeah, this house, there are cracks in the foundation, but they are minor in nature. Seal the cracks, shim the floor to level again, and that will be "like kind" — like it was before.'"

Coviello isn't just an engineer. He's also an elected official: a member of the Portsmouth, New Hampshire, city council. So he has mixed feelings about the remedies applied by insurance awards. "It is a little bit frustrating, as somebody who is conscientious toward federal dollars or state dollars," he notes: "what we are often doing is taking it back to the level that it was prior to the storm — which is still deficient, in terms of, it's going to do it again. We're not bringing structures back to what they should be."

But as an office-holder, Coviello says, he's aware of how tough the public policy issues are. "I don't have a better answer," he says, "and I don't have a way to improve it. Because, certainly the public shouldn't be on the hook to bring somebody's non-conforming property up to code."

The politics of shoreline policy are far more complex than the engineering issues, Coviello observes. "Engineers will often do the right thing because we can make a decision irrespective of emotion: 'Sorry you're losing the house that your family has been in for 150 years, but you're in a flood zone, you've got to move.' You can't do that as a politician—you've got to convince people that you are right. And as a public official who tries to move policy on my local level, I wouldn't want to get anywhere near this because of the politics involved. The challenge that our politicians face—as much as our televisions and newspapers like to make fun of them—is going to be incredible: To get the public to understand a technical matter and have the will to change that. It's mind-boggling to me how we're ever going to get there."