51 Typical Commercial Buildings 18771917

In the period from post-Civil War Reconstruction to about World War I, many of the small and medium towns that now dot the Midwest were settled and built. In general, the sequence of town building in each case was similar. Homesteads were built first, which congregated around crossroads, river fords or ports, depots, mines, sawmills, or other natural points of commercial activity. This was followed by the construction of temporary tent and woodframe commercial buildings. When business activity was sufficient, the temporary wood-frame buildings were replaced by more permanent masonry commercial buildings. Many of these masonry buildings still populate the original downtown areas.

In general, these permanent masonry commercial buildings followed a similar structural design. A typical front elevation is shown in Figure 5.1. Most were made of locally quarried stone or locally fired brick. It was com-

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Figure 5.1 Typical two-story commercial building with load bearing, masonry side walls.

Figure 5.1 Typical two-story commercial building with load bearing, masonry side walls.

mon for the interior wall to be stone and then faced with brick on the exterior side. Sandstone and limestone were commonly used. The mortar for both the stonework and brickwork was generally quicklime from local kilns, and sand from local riverbeds or deposits. The front width of the building was usually 1/2 to 1/4 the length of the building. The long side walls carried most of the structural load.

The roof was simply sloped at a low angle. The high side of the roof was at the front and the low side at the back, as shown in Figure 5.2. Usually, the front of the building had a large facade parapet wall for advertising, as is shown in Figure 5.1. The sides also usually had parapet walls. However, the rear portion of the roof usually did not have a parapet wall. Thus, rainwater parapet facade 7

shed style, simply sloped roof now generally felt strips and tar

Front

storage or living quarters

Rear

store or business area

possible cellar area for storage or coal

Figure 5.2 Cutaway view showing roof slope and floor usage.

Figure 5.2 Cutaway view showing roof slope and floor usage.

drained from the front and sides of the building toward the rear. When the buildings were first built, there would often be rain barrels at the rear corners of the building to catch the runoff.

The original roof was usually a wooden board deck over simple wood beam roof joists. The deck would be covered with various layers of felt and bitumen, roofing rolls, or in some cases, overlapping galvanized metal sheeting. In recent years, many of these roofs have been converted to conventional tar and gravel built up roofs (BURs), or rubber membrane roofs.

The floor and roof decks were generally supported by simple wood joist beams. When it was necessary to splice joists together to span the distance across the side walls, the joists would be supported in the middle by a beam and post combination. Splices were often accomplished by overlapping the two pieces where they set over the support post, and nailing or bolting them together. In many cases, however, the joists were simply overlapped and set side-by-side on top of the post with no substantial fasteners connecting them. It was presumed that the decking or flooring nailed to their upper surface would hold them in place. Additionally, the joists were usually, but not always, side braced to ensure they would stay vertical.

The floor and roof joists were supported at the ends by the side walls. A bearing pocket would be created in the side wall, and the end of the wood joist was simply set into the bearing pocket. Often, the end of the joist was mortared into the bearing pocket so that it would be rigid and vertical.

Usually the bearing pocket only extended about halfway through the thickness of the wall. In some buildings, however, the bearing pocket would go all the way or nearly all the way through the side wall, such that the ends of the floor and roof joists could be seen from the outside. To keep the ends of the joists from weathering, the butts would be covered with mortar, tarred, or painted. Roof decking and floor decking were nailed directly on top of the joists. Figure 5.3 shows the basic structural support system as described.

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