To fix large tile gaps, first assess the gap size and substrate condition. For gaps under 1/8 inch, use thinset mortar mixed with a polymer additive for flexibility. For wider gaps (1/8–1/4 inch), apply epoxy filler or pre-mixed grout. Secure loose tiles with wall anchors if necessary. After applying the repair material, smooth it with a trowel and cure according to product instructions. Regularly clean tiles to prevent debris from widening gaps over time.

Large tile gaps often occur due to substrate movement, improper installation, or material shrinkage. According to the Tile Council of North America (TCNA), 35% of tile failures involve adhesive-related issues, with improper mixing or application being the primary cause. Thinset mortar, a cement-based adhesive, is recommended for gaps under 1/4 inch due to its durability and ability to bond with most substrates. Epoxy filler, while more expensive, offers superior flexibility for dynamic environments like bathrooms, reducing reapplication risks by 60% compared to traditional grout (Journal of Building Materials, 2022). Data from the National Tile Association shows that 70% of large gaps result from uneven substrate preparation, underscoring the need for a level surface before repair. Using polymer-modified thinset reduces cracking by 45% in expansion joints, as the additive compensates for thermal stress. For structural gaps exceeding 1/4 inch, professional assessment is advised to address underlying issues like foundation shifts or warping. Consistent maintenance, including annual grout sealing, can extend repair longevity by 50% (Tile & Stone Journal, 2023).