Webster County Courthouse Tower Restoration
OPN Architects was consulted to survey, evaluate, and restore the Webster County Courthouse Tower and Dome. The exterior survey work was completed by a two-man basket and crane located on the street for the observation assessment of the of the tower, dome and slate roofs. Work took place when the building was occupied as existing exits allowed access out of the building when evaluation work was taking place overhead.
Wind caused the damage of the existing copper sloped roof elements on the tower. While surveying the interior of the tower and dome we found the support wood material for the copper skin was decayed from years of water entering the behind the copper. This wood decay has the caused the copper to sag and prompted additional damage to the secondary structure. The steel support stirrups behind the horizontal copper ornamentation elements were found to rusted or missing resulting in no support for the copper skin. The primary steel structure was essentially undamaged from the water entering the tower. The report provided recommendations of the restoration scope and probable cost estimate for the project to be used for positioning the funds for the project.
The rainscreen tower using both the new and existing copper takes new technology and marries it with the original building system. The original building copper weather barrier was merely acting as a raincoat for the structure. With a new solution to incorporate the weather barrier as the secondary skin, the tower now has a high performance under-sheathing for a modern solution to keep water from the building. Existing copper detail elements were removed, repaired, and reinstalled. Sheet metal elements that have gone missing over the years were replaced as part of this restoration. The building has a new secondary structure to replace the rotted original wood secondary structure. A new roof slate is in process with reproduction of missing copper elements. Since the copper is turning fast due to the run off from the existing copper and climate in Fort Dodge, we have selectively replaced and supported new and original copper skin. Glass skylights over the grand stair space are also included in the current project scope.