Case Study: Failure and Repair of Historic Wood Trusses at St. John the Baptist Church, Hoboken, NJ

Abstract

St. John the Baptist Church in Hoboken, NJ was originally constructed in 1852, and continues to function as Hoboken’s oldest church. The structure consists of mass brick masonry walls supporting rough sawn, scissor type roof trusses. In June of 2010, WJE was hired to investigate the cause of two outwardly leaning masonry walls at the church. The Owner reported that the history of this condition dated back to at least 1902 when three metal tie rods were installed to restrain the spreading of the walls. The condition had reportedly worsened in recent years, including localized failure of the masonry and interior plaster wall at one of the tie rod anchorages. WJE performed an investigation and found severe distress and damage within the wood members of the roof trusses, causing them to exert an outward thrust force on the masonry walls. Cracking of the exterior stucco facade and damage to the masonry at the truss bearings were also noted. WJE then completed an analysis of the existing roof trusses to determine their capacity and to aid in the design of repairs. WJE provided and oversaw the completion of repair recommendations which included; immediate shoring of the existing roof trusses, installation of new upper tie beams and vertical members, installation of new tension rods between the bearings of each truss, masonry repairs at the truss bearings, and stucco repairs at the facade. These repairs were made more complicated by the fact that the building remained functioning as a homeless shelter each evening, necessitating unique repair methods and construction sequencing. This paper provides a unique perspective on the repair of historic wood roof trusses, as well as a brief overview of historic wood construction techniques and their inherent issues confronting today’s engineers. INTRODUCTION Saint John the Baptist Church was originally constructed in 1852 as the First Baptist Church of Hoboken. The church was designed by architect Thomas S. Field in a Romanesque revival style, and was purchased by the congregation of Saint John’s in 1890. Today, the church continues to serve as the oldest church in Hoboken, NJ and also functions as a homeless shelter in the evenings. 1238 FORENSIC ENGINEERING 2012 © ASCE 2013