Indoor expansion joint treatment methods prioritize durability, aesthetics, and structural integrity. Common approaches include sealant application, joint filling materials, and surface treatments. Sealants such as polyurethane or silicone are typically injected into joints to prevent moisture ingress and cracking. Surface treatments like epoxy coatings or decorative fillers enhance visual appeal. For high-traffic areas, removable covers or groutable sealants are preferred to allow maintenance without disruptive repairs.

The effectiveness of these methods hinges on proper installation and material selection. According to the American Society of Testing Materials (ASTM), sealants must meet ASTM C920 standards for elasticity and adhesion to withstand thermal cycling. A 2021 study by the International Concrete Institute (ICI) found that 68% of indoor joint failures resulted from improper sealant application, such as inadequate depth or incorrect curing. In contrast, facilities using ASTM-compliant sealants reported a 92% reduction in moisture-related damage over five years. Additionally, the U.S. Green Building Council (USGBC) notes that decorative fillers extend floor lifespan by 40% compared to untreated joints, as they prevent dirt accumulation and cracking. Proactive maintenance, including annual inspections and sealant replenishment, further ensures longevity. Data from the Building Owners and Management Association (BOMA) reveals that properly treated joints decrease repair costs by 55% annually, as minor issues are addressed early. These practices align with energy efficiency goals, as sealed joints reduce HVAC losses by 15–20%, per ASHRAE guidelines. Ultimately, combining robust materials with systematic maintenance optimizes performance and cost-effectiveness in indoor environments.