Described in this paper are the various types of timber structures with which Ohio has had experience. It includes a discussion of the various timber bridges built in the 1930s, which normally were timber strip floors on steel beams on timber pile abutments and piers. Described also are some of the more modern types of timber structures used including glued-laminated transverse deck panels installed on existing steel beams; longitudinal laminated deck panels that are self supporting; and laminated, panelized timber box culverts. The specifics on these types include actual costs, ease of construction, and performance after installation. The panelized timber structures can be erected quickly with traditional construction equipment. Many treated timber structures, especially glued-laminated structures, have higher initial cost, but lower maintenance costs and a longer projected life.

Ohio has used treated timber in bridge construction for many years. The first bridges built in Ohio were of timber construction and the trend has continued through the years. The most common modern-day type of bridge that utilized timber was the steel beam on timber pile abutments and piers. Standard drawings dating from the early 1930s and most recently revised in 1965 are still being used although on a limited basis. The majority of these types of bridges still in use were built in the 1930s and 1940s. Ohio still has about 1,500 bridges with laminated strip floors in the state highway system. This does not include the hundreds of similar bridges on county and township roads.