TUCKERTON BEACH, N.J. — Contractors slid 80-foot steel beams through the crawl space beneath the beige ranch house. They turned on a compressor, inflating a series of air bags that had been placed under the beams.
Then, slowly and smoothly, the 60-ton structure started its rise above the reach of the next monster flood.
Or so Kathleen Centuolo hopes.
“I can’t wrap my head around it,” she said recently, as she watched the sliver of daylight beneath her house grow wider and wider.
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The post-Sandy rebuilding of the Jersey Shore is well under way, and companies that specialize in elevating houses are in high demand, despite a price tag well into the tens of thousands. It is a massive job that requires skill and careful planning, and along a crowded waterfront, there is an extra wrinkle:
Where do you put the house while building a higher foundation?
Centuolo and her husband, Gus Nisivoccia, are lucky, if you can call someone who’s had to gut a flood-damaged home lucky, because their yard is big enough that the house could be slid out of the way on steel rollers to demolish the old foundation. Amon Construction workers planned to drive stout, 25-foot-long timbers into the soil — 15 feet below ground, 10 above — and the house will be placed on top.
For properties with smaller yards, owner Bob Amon said, he has to break the job down into pieces, moving the house several times because the building’s entire footprint cannot be exposed all at once. If necessary, he will move part of the house so it hangs over the water.
Either way, you need vertical space to drive the long timber pilings into the ground.
On the Shore, such pilings are typically used in areas where the Federal Emergency Management Agency deems that there is potential for high-energy waves — so-called V or velocity zones. The timbers allow space for the water to slosh around in between.
V zones were greatly expanded in FEMA’s new preliminary maps, forcing many owners to make a difficult choice.
The price tag for elevating Centuolo’s house is more than $45,000, including the disconnection of electrical service and plumbing, removal of the old slab foundation and installation of the timber piles. But if they did not have the work done, the couple anticipated their flood insurance would increase by $10,000 a year.
Underneath the house, each of the air bags was surrounded by “cribs” made of short wooden beams. The bags were inflated multiple times, each time lifting the house about 6 inches. In between each inflation, workers added another layer to the wooden cribs to secure their progress.
Hydraulic jacks are another option for lifting a house, but Amon prefers air bags because while they are slower, he said they are safer.
Farther down the shore in Brigantine, N.J., 10 owners have elevated their houses already, while 100 others have started the paperwork to do so, said city engineer Ed Stinson. An additional 650 have expressed interest in seeking FEMA assistance for a home elevation.
Another option for tight spaces is to use helical piles — steel rods that are fitted with spiral-shaped blades so they can be screwed into the ground as supports for a foundation.
The piles are only 6 feet long, so unlike with Amon’s 25-foot timbers, not much clearance is required to twist them into the earth with Bobcat-style equipment. Once one rod is all the way in the ground, the contractor can attach another one on top and then twist again until there is 12 feet of steel underground.
Still more rods are added — 18 feet, 24, 30, and so on until reaching a certain level of resistance, and then the contractor moves a few feet to one side and starts all over.
Once the workers have installed a whole row of the rods, they are “tied together” on top with a concrete beam, which then serves as a foundation for concrete blocks or whatever material is used to elevate the house.
Workers screwed the rods more than 40 feet into the ground.
For houses near the beach, another challenge in raising a house is that the front may rest on sandy soil while the rear is on more solid ground, said structural engineer Harris Gross, a home inspector in New Jersey and Pennsylvania.
With all these issues, he said, skilled labor is essential.
“There are not many companies out there that do this,” Gross said. “You’ve really got to know what you’re doing.”