VA Company Uses NCFI’s TerraThane Geotech Foam System to Save Parking Lot, Time, and Money for NC Municipality

TerraThane and Concrete Jack Fixed this Parking Lot

TerraThane and Concrete Jack Fixed this Parking Lot

MOUNT AIRY, NC—Concrete Jack, Inc. of Williamsburg, VA, a company specializing in concrete leveling and foundation repair along the Eastern Seaboard and the South, used TerraThane Geotechnical Foam system to help save the parking lot of a Wake Forest, NC auto repair business.

"Parking lots are notorious for sinking from failed storm water structures," says Kirk Roberts, division manager for Concrete Jack. "Water causes erosion around the structures, voids form, voids enlarge over time then the parking lot just collapses. Sinkholes can shut down businesses and cause damage to customer vehicles."

Roberts says the municipality’s public works department determined the joints between the four foot sticks of pipe had been improperly gasketed, or seated, during installation. The pipe saw a continuous flow from a small stream entering at an end wall and discharging into a box culvert crossing a public street. The drop inlet at the downstream junction between the RCP culvert and box culvert also failed at the 18-inch RCP culvert feeding it, which had been repaired multiple times using open trench excavation.

Joints of a leaking storm drain pipe sealed up by TerraThane geotechnical foamAccording to Roberts, "Every single joint spread at four feet intervals along the 300 foot pipe was leaking. There were no gaskets in any of the joints, so all that water was escaping the joints and running through the ground beneath the parking lot. The stream ran constantly, eating away at the pipe bedding; even flowing up above the pipe’s springline. The voids averaged six-inches around the pipe, the parking lot was sure to collapse."

Previous attempts at sealing the joints and filling voids around the pipe—and under the floor of a storage building built atop the ground under which the pipe lay—with concrete had failed.

Roberts says the municipality was looking for an affordable, proven, and nondisruptive solution, so his company used a relatively new technology to solve the growing problem. "We surveyed all the joints, drilled holes, and pumped TerraThane high density, hydroinsensitive polyurethane geotechnical foam into them until it came back out of the holes and open joints. The foam fills every crack then expands and cures in place. It’s about the cleanest, quickest, least intrusive product ever invented for geotechnical work." Concrete Jack placed 50 cubic yards of NCFI’s TerraThane, and 45 gallons of polyurethane resin chemical grout over a period of three days to complete the repair without disruption to the adjacent businesses or streets.

Roberts adds, "The old way would have shut down traffic to the business. We’d have had to either tear up the parking lot, excavate, replace the pipes, and replace the parking lot, or use heavy, messy, cement grout and that would only put more undue weight on the ground around the pipeline and be a nightmare trying to work around the four or five other pipes crossing the troubled pipeline. It would have taken weeks or even months, but TerraThane is quick and really cuts down on the amount of people and equipment it takes to do the job."

When asked about TerraThane, Roberts says, compared to other systems they’ve have used in the past, NCFI’s experience and service has been outstanding. "They [NCFI] were one of the first companies to develop plural component polyurethanes for geotechnical applications and they manufacture the highest quality products on the market. They are always on call for us, which is like having a partner who knows everything there is to know about geotechnical applications a phone call away."

The parking lot was saved in record time, the auto repair business stayed open, and the foam fix will last of years to come. Roberts says his company will use TerraThane on their concrete lifting, void filling, and leveling jobs from NY down to NC and all points in between.


For more information or to arrange an interview on this subject contact: Dale McGlothlin, (202) 341-8615

About NCFI

Celebrating 50 years of foam. NCFI, headquartered in Mt. Airy, NC since 1964, manufactures polyurethane foam chemical systems for spray foam-in-place insulation (SPF), geotechnical, agricultural, roofing, marine floatation, packaging, specialty molding, and many other uses. The company also offers a complete line of flexible foams for furniture seating, transportation seating, bedding, carpet underlay, and packaging. NCFI also has manufacturing plants in Hickory, N.C., Dalton, GA., and Salt Lake City, UT. NCFI is a Barnhardt Manufacturing Company, Inc. company. To learn more about NCFI please visit

About Concrete Jack

Concrete Jack was started in March of 2008 serving customers in Williamsburg, VA. Since then, we have grown to serve a diverse group of clients’ concrete repair and soil stabilization needs throughout the entire states of Virginia, North Carolina, Maryland, Pennsylvania, the District of Columbia, and West Virginia using both sand-based grout and high density polyurethane. Concrete Jack also installs cellular lightweight concrete in Virginia, North Carolina, Maryland, Pennsylvania, the District of Columbia, New Jersey, Delaware, and West Virginia.

Preston H. Roberts, Inc, Concrete Jack’s parent company, was formed as an excavating and site work contractor in 2002.

We have worked for all kinds of different customers, from departments of transportation and transit authorities to individual homeowners. Our crews are backed up by estimators and project management staff who started on crews, so everyone our customers interacts with has gotten their hands dirty and knows the right way to tackle settled and uneven concrete. Concrete Jack’s home office is located in Williamsburg, Virginia, at 3402 Acorn Street, Suite 202, Williamsburg, VA 23188. Our crews are primarily based out of Providence Forge, Virginia, with temporary seasonal movements as required by demand. We can be reached on the phone from anywhere, toll free, at (855) 603-6321.