To prevent leakage when installing expansion screws, ensure proper surface preparation by cleaning and drying the substrate to eliminate debris or moisture. Select the correct screw type and size based on material thickness and load requirements. Apply a sealant compatible with the screw and environment around the installation point. Tighten screws to the manufacturer’s recommended torque without over-compressing the collar. Regularly inspect the installation for gaps or misalignment before finalizing.

Proper surface preparation is critical because unclean or damp surfaces reduce adhesion and promote leakage. A 2021 study by the American Society of Civil Engineers found that 68% of leakage incidents in structural fastening systems stemmed from improper surface prep. Correct screw selection ensures the collar expands uniformly, preventing voids. Under-tightening leaves insufficient contact, while over-tightening damages the substrate, both increasing leakage risks. manufacturer-specified torque values, such as those outlined in ASTM F466 standards, maintain consistent collar expansion. Sealants like silicone or polyurethane fill micro-gaps, with industry data showing a 40% reduction in leakage when applied. A 2020 report by the Journal of Construction Engineering noted that 55% of failures in metal-to-metal connections involved inadequate sealing. Combining these practices reduces leakage by addressing root causes: surface quality, mechanical integrity, and environmental sealing.