George, Miles & Buhr, LLC (GMB) provided structural consulting services to Charles County Department of Public Facilities to investigate settlement and a cracked truss at the Richard R. Clark Senior Center in La Plata, Maryland. GMB conducted site visits to observe the areas for repair, during which additional damage was discovered.
The Clark Senior Center is a one story building with a mansard style flat roof and open web truss roof framing. Centered in the cafeteria is a bank of four skylights, which were not originally accounted for in the truss design, and appear to have been added in the field. During our investigation we also discovered that the trusses were field modified to account for bearing changes. These field modifications were leading to failure of the trusses due to buckling and deflection. The extent of damage observed resulted in members and connections beyond repairable conditions.
Due to the extent of damaged observed, we recommended sistering each truss in the rear portion of the building, and removing the skylights in the rear portion of the cafeteria. GMB prepared repair drawings with the proposed recommendation. In addition GMB prepared repair drawings for the repairs to other field modifications observed during our site visits.
As a follow-on to the structural investigation, Charles County commissioned GMB to perform an architectural study of the flat roof, to identify the capacity of drainage required for a 100 year storm event in comparison to the existing interior flat roof drain volume currently provided. In addition, a cursory evaluation of the existing flat roof was done to identify any problems such as ponding areas that no longer provide positive drainage to the existing interior roof drains, the condition of the existing membrane roof, drain covers, flashing at roof penetrations and skylights as well as diversion of drainage around these penetrations to prevent ponding.
GMB’s report included an existing conditions study, code evaluation, roof warranty review, and long-term maintenance recommendations.