Local company employs "western" technology to stabilize home foundation

Crews with Cooper River Contracting pour and spread out concrete for the foundation of a home at Rushland on Johns Island. Post tension sounds like what you might get after negotiating fierce whitewater rapids or plowing through an hours’ long law school exam, the nervous energy from completing hair-raising or pressure filled assignments. But at least in construction circles, post tension is something quite different. It is used on commercial structures to secure them because of their size. And on the residential side, it is popular in California and the arid Southwest, where caked soil can shift and cause homes to crack. Where post tensioning is unusual is on concrete home foundations in the Charleston area. Locally-based Cooper River Contracting, which is getting into the practice, believes it is one of the first to use the technology to stabilize a home under construction in the Rushland neighborhood, close to the Stono River on Johns Island. The builder is Goldin Houser Construction and Development, and the architect is Allison Ramsay Architects Inc. “I think this is way faster, and cheaper,” says Eric Moultrie, foreman for Cooper River Contracting on the recent job. The damp, muddy soils of the South Carolina Lowcountry wouldn’t seem on the surface like the right place for a procedure that’s popular in dry climates. But just as hot baked soil can be unstable, so can moist earth. Tightening the concrete with steel can keep the foundation in one piece in caseof settling. At the same time, it’s a less expensive and evasive procedure than alternatives such as such as pile driving, says Les Taylor, owner-partner with John DeWitte of Cooper River Contracting. Cost savings can be $20,000, for instance, on a large two-story house. With post tension construction, the concrete foundation is poured and steel reinforcing bars set. Then steel cables are tightened in place, thereby holding the concrete together while spreading the tension across the slab rather than confining it to certain places, which can cause cracking or other damage. “This is far from new technology, but it’s new technology here,” Taylor says.