What Happens to Hardwood Floors After Water Damage?

Hardwood is porous, so it drinks in moisture like a sponge. When water soaks into the planks, the wood fibers swell. This swelling can make the floor feel uneven underfoot. You might notice edges lifting or the surface becoming rough.

As the wood dries, it shrinks again, but not evenly. That uneven movement can create gaps between boards or cause them to cup, where the edges rise higher than the center. In severe cases, boards can buckle and pull away from the subfloor entirely.

• Cupping: edges rise, center dips
• Buckling: planks lift off the subfloor
• Discoloration: dark stains or gray spots
• Splitting: cracks along the grain
• Mold growth on the surface or underneath

The longer water sits, the deeper it soaks. Within hours, the finish may start to bubble or peel. After a day, the wood can begin to warp. Mold can start growing on damp wood in as little as 24 to 48 hours.

You can help by blotting standing water with towels and using fans to circulate air. But if the water came from a leak or flood, the source needs to be stopped first. In humid climates, drying can take longer, so professional help is often wise.

Start by removing as much water as you can with towels or a wet vacuum. Open windows if the weather allows, but in a humid place, that might not help much. Use fans to keep air moving over the floor.

Do not try to force-dry with heat, as that can cause more cracking. Call a professional if the water came from a contaminated source or if the floor has been wet for more than a day. They can also help document the damage for your insurance claim. Policies vary, and your insurer decides what is covered.