(First of two parts) One garage is not perfect for all. There are differences between garages for school buses and transit buses. But the hypothetical garage described below will have parts from which all garages can find some pieces. Metal-pole structures are the best. They are simple and relatively inexpensive to construct. They also are easy to repair should the building become damaged. Finally, they are also well adapted for expansion. Concrete for the structure is broken down into two groups - walls and floors. Walls should be about 12 inches thick with reinforcement bars. The concrete wall should be approximately five feet high. Above that, metal corrugated siding can be used. That will be more cost effective and will assist in future expansion projects, should they require the movement or elimination of walls.
Floor requires reinforcement
Unlike the typical concrete slab, the poured floor has some special considerations. The general areas should be eight to 10 inches thick, with steel reinforcement bars and grid mesh. The floor in the repair and tire-change area should have a thicker concrete to accommodate jacks and stands, which concentrate a high force over a small area. That will prevent punch-through or any localized cracking. The concrete floor must also have other components built into it: longitudinal floor drains, preferably down the middle of all expected wet areas, and a toilet dump drain with a mesh screen. The electrical supply throughout the building should be laid out to assist the mechanics as much as possible. Waterproof wall outlets (110 volts) should be placed along the walls at 12- to 15-foot intervals. They are best at 45 inches above the poured floor. That will prevent accidental contact with water. Additionally, each wall should have at least two 220-volt outlets. Your monthly electric bill aside, you can never have too much lighting. Fluorescent tube lights are ideal. Place them 12 to 15 feet from the poured floor. They may be spaced in a 12-by-20-foot grid pattern. Wire the lights so they can be controlled in a mixed circuit arrangement. That will prevent a total blackout in any one area if a circuit breaker is tripped.
Plan for hoist installations
If portable electric hoists are used, two additional concrete slab concerns need to be addressed. For every hoist used, a footing needs to be poured where it will be used. Obviously, planning is required to locate the dedicated hoist locations. Once the slab is poured, the hoist footings are covered by the slab and marked with permanent concrete paint to assist the mechanic in locating the positions for the hoist. If the cost of this extra effort seems prohibitive, remember that the extra cost is negligible compared to the cost of repairing broken concrete years later. Of course, the garage should have space for maintenance procedures. Specifically, heavy and light maintenance areas are ideal in that these dedicated spaces will not interfere with other areas in the building. Heavy maintenance areas should be specified at about 900 square feet per 30 fleet vehicles. A "dead man" located at the rear of this floor space provides mechanics with the ability to pull on the vehicle’s structure or specific component, such as power module, for removal. The dead man is simply an anchor point in the concrete with the ability to resist force. It is helpful when straightening body structures. Additional air hose connections and electrical outlets should be added to this area. Light maintenance areas should be specified at about 750 square feet per 30 vehicles. This area should have the same slab thickness as the remaining floor space. No special provisions need to be addressed for this space. However, space for light maintenance must be reserved so as not to interfere with the flow of traffic within the building.
Christopher Ferrone is vice president of fleet logistics and engineering at American Sightseeing in Chicago and president of Americoach Systems, a transportation consultant.