The design of floor expansion joints presents an engineering challenge. They must handle transverse horizontal opening and closing movement, longitudinal differential or shear movement, and vertical differential shear movement. These requirements are similar to the movement demands of wall, ceiling, and roof expansion joints. What makes the design of floor systems so challenging is that they must perform these movement functions while also providing a strong “bridge” that can bear point loads and provide a smooth, quiet transition for wheeled traffic, as well as a slip-free surface for pedestrians.
Manufacturers of floor expansion joints have used a variety of approaches, with varying degrees of success. The available products fall into three design categories:
Rubber and Rail Systems
The most common and least expensive system comprises two extruded-metal (usually aluminium) angles, between which an elastomeric filler is inserted or adhered. To enable expansive and compressive movement, the insert needs to be a soft, elastic material and/or shaped into a bellows form. However, soft materials and bellows shapes are incapable of resisting even relatively small point loads. Because the rubber material is soft, wheels sink in and bang against the metal angle on the far side of the joint. This results in a nasty jolt to patients and medical equipment, causes damage to the adjacent flooring, and results in early failure of the expansion joint itself.
Cover Plate Systems
To provide better point load resistance, a second product category employs a metal plate. The plate can be anchored on one side, can float between clamping plates, or can be held in the middle with a centering bar. These systems provide a stronger bridge than rubber and rail systems, and they are capable of handling small to moderate point loads, although manufacturers regularly fail to provide point load ratings from which to match models to expected traffic loads. Most of these systems are especially poor at handling floor height differences or vertical differential movement, which causes the cover plate to float unsupported at various locations. This phenomenon makes cover plates noisy, and when deformed by the torque of differential vertical movement, can result in a tripping hazard. Additionally, the gaps under the cover plates create cleaning problems, as moisture and dirt collect in the recesses—an unacceptable hygiene problem in a healthcare setting. Finally, because there is a transition on each side of the cover plate, wheels bump twice during transition over the joint.
Solid-Interlocking Systems
A purpose-designed alternative interlocks two extruded metal components in a design that accommodates horizontal opening and closing, as well as differential lateral and vertical movements, while providing high point load resistance. This solid-interlocking system was specifically designed to withstand the pounding from small-diameter, hard wheel traffic, while respecting aesthetic integration with adjacent flooring materials. The design provides a smooth, quiet rolling surface. Integrated gaskets that seal out dust and dirt are also thoughtfully engineered features for hospital environments.
At Dseal, we are committed to providing floor expansion joints that meet the rigorous demands of healthcare facilities. Our Dseal expansion joints are designed to handle high point loads, ensuring durability and safety for both people and equipment. Choose Dseal for reliable, high-performance expansion joint solutions tailored to the unique needs of medical environments.