Subfloor Water Damage Repair: Steps and Costs Explained

If your floor feels soft, buckled, or smells musty, you might have water damage hiding underneath. And when the damage reaches your subfloor, you’ve got to act fast—before mold sets in or structural problems get worse.

I’m Tyler Zimmerman, owner of Total Home Water Restoration in Grove City. I’ve repaired hundreds of subfloors in homes around Columbus, Hilliard, and Westerville. This guide will walk you through what to expect if your subfloor is water-damaged, what the repair process involves, and what it really costs.

Signs Your Subfloor Is Water-Damaged

Water-damaged subfloors can go unnoticed for a while, especially if they’re under vinyl, carpet, or tile. Here’s what to watch for:

• Floors that feel soft, bouncy, or “give” when stepped on

• Musty smells that don’t go away

• Warping, cupping, or cracking in wood floors

• Stains, mildew, or mold near baseboards or vents

• Squeaky areas that weren’t there before

If you see any of these, it’s time to check underneath.

Common Causes of Subfloor Water Damage

We see subfloor damage most often after:

• Leaky kitchen or bathroom pipes

• Overflowing toilets or tubs

• Water heater failures

• Long-term humidity or improper ventilation

• Poor sealing around showers, tubs, or windows

Once water gets below your finished flooring, it can soak into the plywood or OSB and weaken it. Left untreated, mold can form within 48 hours.

Step-by-Step: How We Repair a Water-Damaged Subfloor

Here’s how we do it at Total Home Water Restoration:

1. Inspection and Moisture Reading

We use moisture meters and infrared cameras to find exactly where the damage is and how deep it goes.

2. Tear-Out of Damaged Flooring and Subfloor

We remove the affected flooring (tile, wood, vinyl, etc.), then cut out the water-damaged subfloor sections. Everything is disposed of safely.

3. Drying and Mold Treatment (if needed)

If moisture is still present, we’ll set up commercial air movers and dehumidifiers. If mold is visible or suspected, we follow IICRC S520 standards for safe mold remediation.

4. Rebuild the Subfloor

We install new, code-compliant subflooring. For most homes, that means tongue-and-groove plywood or OSB panels glued and screwed to the joists. If needed, we also repair or sister the joists underneath.

5. New Flooring Installation

Once the subfloor is solid and dry, we install your choice of finished flooring—hardwood, LVP, tile, or carpet.

What It Costs to Repair Subfloor Water Damage in Ohio

Prices vary depending on the size of the damaged area, type of flooring, and whether mold treatment or joist repair is needed. Here’s a ballpark:

Type of Repair Estimated Cost Minor repair (small area) $800–$1,500 Moderate repair (bathroom/kitchen) $1,500–$3,500 Major damage + mold or joists $3,500–$7,000+

We always provide clear estimates, photos, and a scope of work before we start.

Should You File an Insurance Claim?

If the damage was sudden—like from a burst pipe or failed water heater—your homeowner’s insurance may cover the repairs. Gradual damage from poor maintenance usually isn’t covered. We can help document the damage for your adjuster.

Call Us Before the Problem Spreads

If you think your subfloor might be damaged, don’t wait. The longer it sits, the worse (and more expensive) it gets. We’re based in Grove City and serve Columbus, Dublin, New Albany, and surrounding areas. We fix your home like it’s our own—straightforward, honest, and done right.

Call Total Home Water Restoration at 380-246-1837 to schedule your inspection.