Water Under Tile Floors: How to Know If It's There

Water under tile floors is often hidden, but your senses can give clues. Walk barefoot across the floor and notice if some tiles feel cooler or warmer than others. A temperature difference can indicate trapped moisture beneath the surface.

Look closely at the grout lines. Cracks, gaps, or crumbling grout let water seep underneath. Also check for efflorescence, a white powdery residue, which forms when water evaporates and leaves minerals behind. If you see it, moisture is likely present.

• Hollow sound when you tap the tile
• Tiles that feel loose or move slightly
• Dark spots or staining on grout
• Musty or damp odor near the floor
• Visible water pooling in low spots

Water usually finds its way under tile through damaged grout or cracks in the tile itself. Leaks from nearby plumbing, such as a toilet or sink, can travel along the subfloor. In homes with radiant heating, a pipe leak can saturate the layer beneath.

In Burnsville, with its humid continental climate, high humidity can also contribute. Moisture can wick up through concrete slabs, especially in basements. If you notice persistent dampness, consider improving ventilation or using a dehumidifier.

You can handle small, localized moisture, but widespread water under tile often requires professional help. If you notice multiple loose tiles, significant staining, or a persistent odor, it's time to seek assistance. The pros can assess the extent and recommend the right steps.

They have equipment to detect hidden moisture and dry out the area properly. Depending on the source, they may need to remove and replace tile, repair the subfloor, or address underlying leaks. Early intervention can prevent mold and structural issues. Policies vary, and your insurer decides what is covered.

• Multiple loose or hollow-sounding tiles
• Water stains spreading on walls or ceilings below
• Persistent musty smell that won't go away
• High moisture readings on a meter
• Signs of mold growth in grout lines