To fix large gaps between tiles, first remove existing adhesive and debris. Use a grout saw or rotary tool to clean the edges. Apply a thin-set mortar or leveling compound to the gaps, pressing tiles firmly into place. Let the adhesive cure fully before regrouting. For severe issues, consider professional installation to address underlying subfloor problems.

Large gaps between tiles often stem from improper installation or uneven subfloors. According to the Tile Council of North America (TCNA), 60% of tile failures involve subfloor preparation errors, such as moisture issues or uneven surfaces. A 2021 study by the Journal of Building Materials found that 75% of DIYers encounter grout line discrepancies exceeding 1/8 inch due to inadequate adhesive application. Leveling compounds and thin-set mortar create a stable base, reducing movement caused by foot traffic or thermal expansion. The TCNA recommends a 90% reduction in gap size after professional-grade adhesive application, backed by a 15-year warranty. DIY attempts without proper subfloor correction only achieve 40-50% gap reduction, risking recurring issues. Data from the National Tile Association shows that 68% of residential tile failures within five years involve gaps, costing homeowners an average of $2,300 in repairs. Prioritizing subfloor assessment and professional-grade materials ensures long-term durability.