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Pinning the PinnaclesArticle reprinted from Clem Labine's Traditional Building -
GRACE EPISCOPAL CHURCH, 254 Hicks St. Brooklyn, N.Y. Architectural Conservators: Integrated Conservation Resources; Architect: Page Ayres Cowley, AIA; General Contractor: Cathedral Stone Co. of NY; Structural Engineers: Superstructures; Mechanical Engineers: Ambrosino DePinto & Schmieder. The innovative, British-made CINTEC stainless steel anchors are rather like large scale dentistry. A small hole is drilled into the damaged area and polyester-wrapped pins inserted -- crossing each other like underpinnings. The polyester sock is then pumped full of grout, filling the sock from back to front. PROBLEM: The brownstone masonry of this 1847 Richard Upjohn church was badly deteriorated and previous repairs were found to be incompatible with the stone. Furthermore, the pinnacles over the roof had been encapsulated in a dense cement that had undermined their structural integrity. SOLUTION: A series of tests were conducted on both the original sandstone and potential repair materials to find a mix which satisfied such needs as vapor permeability and water absorption rate. "Our conservators also found Upjohn's original stone specifications which named the original quarry. With this information, we were able to obtain specific geological survey data from the period," says Glenn Boornazian of Integrated Conservation Resources, Inc., the project's conservators. "This helped to develop a program of compatible repair." To document the large project, computerized drawings were done stone-by-stone of the building's west elevation, with the drawings later annotated to quantify individual conditions. But perhaps the most interesting repairs involved using the new CINTEC anchor system, purchased through the Canadian office of the British manufacturer. "We had the good fortune to meet Robert Lloyd-Rees, who had used the system in England," says project architect Page Ayres Cowley. "The device satisfied the engineers' requirements and mine, without altering structural integrity." This procedure uses specially designed stainless steel pins, varying from 24- to 40-in. long, and encased in polyester "socks." To anchor loose stone, a small diameter hole is drilled into the stone and the pins inserted. Then, grout is injected under pressure into the sock, which, inflating like a balloon, provides a mechanical as well as a chemical bond in the substrate. "The problem in the past," Cowley says, "is that you had to insert a rod and pump epoxy around it. When epoxy is pumped in. it can run all over the place and not produce a structurally satisfactory connection. This new pin system seems to be a more satisfactory way to deal with localized failures in stone." FOR FURTHER INFORMATION: Neal Boornazian, Cathedral Stone Co. of N.Y., 10 Columbia Place, Brooklyn, NY 11201 Phone: 718-858-5646 FAX: 718-858-5657 Previous Page | Religious Buildings Menu | Home | Next Page CINTEC, CINTEC MC Systems, Presstec and Archtec are all Registered Trade Marks, Copyright ©1996-2002 |
