Centralia Correctional Center

Summary

Kaskaskia Engineering Group, LLC (KEG) performed a visual inspection and documentation of Building #C2937 (Pole Barn) at the Centralia Correctional Facility in Clinton County, Illinois. The purpose of the structure inspection was to evaluate the condition of the timber framing members and roof trusses prior to the anticipated replacement of the roof.

Project

Building #C2937 was originally constructed in approximately 1979. The structure was then extended 72 feet to the east in 1982. Both the original structure and extension appear to consist of a Better Built Buildings timber post-frame structure with metal siding and roofing. The overall size of the building is 147 feet by 40 feet. The long axis of the structure runs east/west, with 7 overhead doors along the north face. The structural components of the building include a concrete slab, 6×6 nominal treated wood posts, and prefabricated timber roof trusses with a roof slope of 3½”:12”. The wood posts and roof trusses are spaced at 8’-0” in the center, with 2×6 purlins at 2’-0” in the center. The posts are connected via 2×6 girts at 2’-6” on center and a 2×12 header along the top of the posts.

Based on the existing conditions, it was found that the 1982 addition could be rehabilitated in place with minimal effort. The following structural items were recommended to extend the life of the 1982 addition:

• The 6×6 vertical post should be replaced. In order to accomplish this, the roof truss at this location should be temporarily supported and a new treated 6×6 post-installed while the roof is off. Additionally, all vertical post bottoms should be exposed and inspected during construction to determine if additional posts require replacement.
• The purlins along the ridgeline should be replaced with newly treated 2x6s.

The condition of the original 1979 portion of the building justifies either rehabilitation or replacement. In order to rehabilitate this portion of the building, it was recommended that the following items be completed:

• The 2×12 timber headers along the north and south walls should be replaced.
• The 2×6 purlins should be replaced.
• Because of the deterioration of the roof truss connection plates and nail heads, the roof trusses should be replaced.
• New timber headers should be installed above the overhead doors to transfer the vertical loads from the roof trusses to the adjacent vertical posts.

The inspection and report were completed in September 2019.