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Can piers prevent sinkhole damage? Engineers have doubts

Can LRE Ground Services Inc., a Brooksville company well known for fixing sinkhole damage, actually prevent it?

The company would like you to think so, which you probably know if you watch much cable television.

For months, the company has been running an advertisement touting the use of "helical piers" to stabilize the foundations of homes — not after they have settled into sinkholes, which has long been common, but before the houses are built.

True, the female narrator in the advertisement never directly says the piers prevent sinkhole damage. But the nightmarish shot that opens the commercial — of a home's foundation hanging over a newly opened void — suggests that sinkholes are one of the "risks" that she says can be averted by installing piers.

And if this isn't stated explicitly in the commercial, it is on the company's website, which includes a page with the heading, "Our pre-construction piers can protect your home from sinkholes."

No, they can't, says Anthony Randazzo, a retired University of Florida geology professor and co-owner of Geohazards Inc., which analyzes sinkhole claims for homeowners and insurers.

"From a geological point of view, that's sheer nonsense," Randazzo said. "Helical piers are not addressing the conditions of sinkhole activity."

As many of us here in the heart of the state's Sinkhole Alley already know, there are two basic methods of stabilizing a sinkhole-damaged foundation, often used in tandem: grouting, which entails pumping large amounts of a concrete compound into these voids, and underpinning, in which workers attach the foundation to piles that extend deep into the ground.

Helical piers are a type of pile, screwed into the earth rather than driven.

The resistance that develops with this screwing action gives the impression that these piers can provide stability before they even reach the base layer. But cavities in the base layer of limestone can still give way, Randazzo said, rendering the piers useless.

Yes, helical piers can prevent settling caused by less-dramatic sources such as muck, debris or clay in the soil, said James Funderburk, a geologist and geotechnical engineer from Riverview. In fact, elsewhere on the LRE website, the company states this is the piers' main purpose.

The problem is their initial price, Funderburk said, especially because the foundation must also be reinforced to effectively support it.

Though the company said the process costs about $25,000 for a typical home, Funderburk said that when done correctly, it could add as much as $100,000 to the price of a home that would otherwise be worth $250,000.

"It's not a cost-effective method of supporting new construction on a deep foundation," he said.

It can be, said Tony Sturgess, a manager for a large international construction firm, who had the piers installed at his new, high-end, 4,500-square-foot home in suburban Orlando.

The piers added about $80,000 to the price, but allowed Sturgess to build on a lakefront lot that was prime in every way other than the thick layer of muck in the soil.

"It's not something you want to do if you plan to flip the property," Sturgess said. "But if you have a home with a high level of finish, and you don't want it to move, it's the ticket."

LRE stays out of the decision of whether piers are right for a home, said Jim Flynn, spokesman for company, which is not the only company offering this product, but is the most aggressive in pitching it.

LRE only puts in piers when they are recommended by engineers, he said. "The engineer is the doctor; we're the pharmacist."

Actually, I'd say they are more like drug companies — the ones that run "ask your doctor about" commercials to generate demand.

They are doing it, I suspect, because demand for the traditional use of their services is dropping like an undermined pool deck.

Sinkhole claims are falling around the state, a delayed impact of the 2011 state law that made it more difficult for homeowners to accept payments from insurers without fixing sinkhole damage.

For example, the number of new sinkholes in Hernando County, the perennial state leader in sinkhole claims, declined from 1,085 through June 30 last year to 271 during the same period this year.

If this is LRE's strategy — trying to create a new market for an established product — how's it working?

Flynn said the company has installed the piers in "dozens of homes." But no separate permit is required for installing piers as part of a foundation, making it difficult to track in public records.

In any case, I'm betting it doesn't catch on like the now-stalling trend of filing sinkhole claims with insurers.

That was fueled by the prospect of getting something — either expensive repairs or a cash payout — for nothing.

The big disadvantage to a company pitching sinkhole prevention: It has to convince homeowners to pay for it out of their own pockets.

Can piers prevent sinkhole damage? Engineers have doubts 07/03/14 [Last modified: Thursday, July 3, 2014 2:16pm]

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