The Cathedral Stone Newsletter
Historic Brick Wall Scheduled for Demolition Saved by Jahn M30
The Cathedral Stone Newsletter, July 2006
The condominium complex at 241 Eldridge Street was constructed in 1904 in the Lower East Side of Manhattan. Architect Scott Henson was hired by the condominium board to perform a full exterior analysis of the building. The analysis revealed a number of necessary repairs, including brick, window, and terra cotta replacement and repairs, mortar joint cutting and re pointing, as well as the replacement of the roof membrane and cornice. During removal of the parapet walls, the internal conditions of the brickwork and mortar were found to be severely deficient. The back-up masonry was loose laid in many areas with no mortar.
The failures of this building were directly attributed to the mortar. The mortar used in the original construction of this building consisted of a high-lime content resulting in little or no binding between the mortar and the bricks. The mortar within the walls was loose and powdery. Adverse weather conditions and poor maintenance over the life of the building accelerated the deterioration of the mortar. Several structural engineers were invited to the building to inspect conditions and provide recommendations. The consensus was that the walls required complete reconstruction from the ground up. This solution was prohibitively expensive for the building owners; therefore and extensive search was undertaken for an alternative solution to repair the internal condition of the walls.
After the research and testing of many masonry techniques and products, including mechanical pinning, brick repair products and soil consolidation products, Cathedral Stone Products’ Jahn M30 Micro Injection Grout was found. When injected, Jahn M30 will travel into the substrate and continue until it flows freely from this port and other ports at the same level. The ports are then sealed using non-staining clay, sealant, or caulk. A series of injection ports must be drilled on the face of the substrate to create a “drill frame.” Ports should be drilled in a downward direction. Cathedral Stone Products, Inc. supplied Jahn M30 Injection Grout for a test area. Cathedral Stone Products representatives, including Dan Perakes, conducted the initial testing on the building. A second and larger test was performed to confirm initial results. This test involved injecting the Jahn M30 into specific areas in the walls to determine whether or not the repair process was going to work. Jahn M30 again proved successful. Extensive testing was performed until the correct installation procedures and amounts of grout required were determined to consolidate the existing lose, powdery mortar, to fill the voids between the internal brickwork, and ultimately to provide a structurally stable building.
It was originally thought that the cost to replace the exterior walls would be an estimated $1.8 million. The repairs would have to be completed section by section. Because of the success of Jahn M30 the entire project cost was $106,000 saving the owners over $1.6 million. Scott Henson Architects hired Viles Contracting Corporation to complete the repairs. From February 9th to April 22nd, 2005, they drilled 1,435 holes into the building and pumped in 1,280 gallons of the M30 Injection Grout.
After 241 Eldridge Street was completed, the project was featured in the NY Times and drew interest from the engineers with the New York City Housing Authority (NYCHA). They wanted to look at the project to see if the repair method was a viable alternative for maintaining their buildings. They met with both Cathedral Stone Representatives as well as Scott Henson. In the summer of 2005, CSP successfully completed Jahn M30 Injection test of the New York City Housing Authority. They are currently monitoring the tests and are considering using the method of restoration for future projects.