A Concrete Design Works for Car Washes and C-Stores

Has the “perfect” system for building car washes and C-stores been discovered at last? Shell Oil’s John Dove, P.E, reports.

How do you build a car wash building at a service station that will withstand an extreme environment, require minimal construction time, be easy to keep clean, require minimal maintenance and still be affordable?

These questions have been asked by building design engineers at Shell Oil Products Company for many years. Approximately two years ago, they set out to solve these problems, once and for all, with a goal of finding the ideal car wash building. After trying and evaluating many solutions that used various building materials and designs, they concluded that every alternative had drawbacks.

• If the building was durable, it required longer construction times and expensive coverings or sealants on the walls and ceiling surfaces.

• If construction time was fast, the materials deteriorated quickly and the building was expensive.

• If the materials were inexpensive, cleaning and maintenance costs were high.

Ideal prototypes?
All traditional construction methods were considered; but for one reason or another, each fell short of the "ideal" building. This building would need to have four characteristics. It would need to be:

(1) durable;
(2) easy to clean and maintain;
(3) quick to construct; and
(4) affordable.

The Shell engineers then learned of an unusual building system design that uses concrete-filled, polymer resin based wall panels. Known as The Royal Building System,™ it is patented and produced by Royal Group Technologies of Toronto, Canada. Shell engineers then designed a new application for the system to create a car wash that met the four requirements listed above. The next step was to try some prototypes.

Two car washes were built at service stations in Houston with the system. Based on the success of these two structures, Shell and Royal built 14 more car wash projects in other parts of the country, using this same design. Each one was durable, easy to clean and maintain, quick to construct and affordable.

These five photos show the sequence of installation steps in the erection of the building:

1. A conventional foundation and floor are poured with vertical steel rods placed at intervals along the wall centerlines. When the concrete has cured sufficiently, the wall panels are then assembled as detailed on the wall layout plan.

2 Beginning with a corner section, the interlocking panels are slid into place over the vertical rebars and into the groove of the adjacent panel. Where horizontal rebars are required, they are slid through the panel cores as the wall assembly progresses.

3. Assembly of the wall panels continues until all are in place using the various types of panels required to achieve the desired wall configuration. Bracing is used to maintain the position of the walls until they are filled with concrete.

4. The wall panels are filled with concrete from the top, preferably through use of a concrete pump. The cored openings in the panels were designed to facilitate the even flow of concrete throughout the panels as they are filled.

5. Roof panels are then slid into place and secured to the walls.

A number of challenges were faced and solved in creating the new car washes. These challenges included:

• Adapting a building system that had been used almost exclusively for residential purposes to a different set of requirements faced in commercial applications. This building system has also been used on a convenience store. This store, which has just been completed, was seen by the owners as a success. The quick erection of the walls of the store (three days) translated into significant cost savings. Another project recently completed was a 21,000 square foot office building, which was completed in about four months.

• Achieving an image or appearance using the panels that would be acceptable without incurring the additional expense of applying architectural wall coverings or veneers. The flexibility of the system in both pigmenting the panels and in achieving difficult shapes allowed construction of a building that met image requirements at minimal cost. Part of this image included the yellow elliptical columns shown in the photographs on page 15.

• Satisfying building codes. As with any new building design, this system needed to satisfy building codes. Thus far, Building Officials and Code Administrators (BOCA) International has approved the system for type 5B construction. Numerous local government entities have also granted building permits for the system. Application has been made to the International Conference of Building Officials (ICBO), and approval is pending.

This diagram shows how the wall system is constructed. Panels are available with or without the insulation chambers. Wiring raceways can be placed where needed

Where and how it works
First introduced in 1991, The Royal Building System™ was used primarily in entry level housing in emerging markets. Since then its uses have been expanded to include schools and light commercial structures in more than 23 areas around the world, including the Caribbean, South America, Asia and Europe.

The system consists of hollow, interlocking panels made of a specially formulated polymer resin compound. The compound is formulated to provide protection against UV degradation, improve weatherability, resist severe fading and maximize color retention. Without this patented formulation, the system would not be suitable for use as a building material.

The panels are also an improvement over conventional building materials such as wood, masonry and steel in that the extrusion process produces sections that are consistently uniform in size, shape and appearance. This allows a high quality finished product without requiring highly skilled craftsmen. The significant improvements in construction time come from the fact that the panels are designed for fast assembly, both in erecting the panels and filling them with concrete. These components can be made in a variety of shapes and sizes to accommodate unique building designs.

By designing the building in the same way that one would design a conventional reinforced concrete structure, relatively wide, open spans can be achieved without the use of exposed steel lentils or support members. This allows enormous flexibility in designing large windows or openings in car washes without introducing the maintenance problems associated with exposed steel or wood.

Assembly and erection of the building does not typically require highly skilled laborers as long as a competent, trained supervisor is directing the process. Erection of the building usually follows the sequence shown on page 15.

If a custom exterior treatment is desired, virtually any siding, masonry or veneer can be applied. These would be applied to the wall surfaces in much the same way as they would be applied to walls made of conventional materials. Products are also available that are specifically designed for use with this system, such as vinyl stucco. Again, considerable flexibility is possible.

As with any building material, these panels must be incorporated into a well-engineered solution designed to ensure that the structure will meet design requirements as well as to comply with applicable codes. For this reason, the building system includes the engineering design and erection of the structure.

Recognition of the many potential applications of this building design, particularly in the petroleum industry, has led to the formation of Royal Landmark Structures, L.L.C., the exclusive U.S. licensee in the upstream and downstream petroleum business. Royal Landmark Structures is a joint venture between Royal Building Systems (Cdn) Limited and Shell Chemical Holdings Inc. It was recently formed to design and construct buildings and other structures for customers in various industries.

Use of the system allows the flexibility to provide a large window opening.