Flooring After Water Damage: Five Questions That Decide What Stays

The most common mistake after a leak is judging the floor by its surface. A waterproof vinyl plank can look dry while water sits on the subfloor underneath it, and that hidden layer is the one that has to dry within 24 to 48 hours, the window the EPA gives for drying water-damaged materials before mold can start.

So, what to do with flooring after water damage: stop the water, get it off the surface, find out whether it reached underneath, and lift whatever keeps the subfloor from drying. Whether the floor can go back down depends on what kind of water it was, what kind of floor you have and how long it stayed wet.

The five questions below take them in order.

Where the steps come from: the EPA’s guidance on mold and on flooded homes, and the installation manuals and warranties of the floors we sell. We are a flooring supplier, not a water restoration company, so where the EPA says to call a professional, so do we.

Question 1: Was it clean water, or floodwater and sewage?

First stop the source: close the valve, unplug the appliance, and keep clear of outlets and cords near standing water. Then sort the water, because the answer changes every step after it.

• Clean water, such as a burst supply line, an overflowing sink or tub, or rain through an open window: go on to question 2.
• Floodwater, a sewage backup or water carrying chemicals: call a professional who has worked with contaminated water. The EPA’s mold remediation guide says exactly that, notes that its drying steps are written for clean water, and warns against running fans before you know the water is clean.
• An older house with vinyl floor tile: the EPA’s flooded-homes guidance warns that vinyl floor tile may contain asbestos and says not to remove asbestos-containing tile, even damaged tile; that work goes to an asbestos professional. Chesapeake’s installation guides carry the same warning about old resilient floors and black asphalt adhesive.

Deep water has its own hazard: the EPA cautions that pumping out several feet of water too quickly can crack and collapse walls and floors.

Question 2: Did the water get under the floor?

If a spill stayed on top and was wiped up the same day, the waterproof flooring we stock in North Charleston and Richmond is built for it. According to Chesapeake’s laminate warranty, topical spills cleaned up within 24 hours are covered, and PermShield warrants its SPC vinyl as waterproof from topical moisture.

What each of those words covers is in our guide to waterproof vs. water-resistant flooring.

Assume water got underneath if any of these is true:

• Water stood on the floor or ran to the walls, where the expansion gap leads straight down to the subfloor.
• It came from below or behind: the slab, a wall cavity, a supply line under a cabinet.
• The leak ran for hours, or was found days later.

Under the floor is where the damage happens. PermShield says its planks keep their integrity when water lands on them, but when water flows between the planks onto the subfloor, mold and mildew can grow, because luxury vinyl plank is not a moisture barrier.

Chesapeake describes its laminate the same way: resistant to water, not a moisture barrier. For vinyl and similar hard floors, the EPA’s drying table says to check that the underflooring is dry, and to dry it if it isn’t.

Question 3: What kind of floor is it?

Floating SPC vinyl or laminate

A click floor comes apart. PermShield’s manual releases the end joints by sliding the planks apart sideways, so rows can be lifted to let the subfloor dry. Photograph the layout before the first row comes up, and stack the planks flat.

Whether a plank can go back is a decision for after the subfloor is dry. PermShield’s manual warns that any gapping can compromise the locking system, so a plank that no longer closes tight stays out.

Laminate is the less forgiving of the two: the European laminate makers’ association, EPLF, says the joints of a laid laminate floor are sensitive to moisture and that spilled water should always be mopped up right away.

Glued vinyl

Glued planks don’t lift in rows, and on a glued SPC floor the adhesive’s maker sets the moisture limits, as PermShield’s manual points out. Read the adhesive label before deciding what can stay.

Engineered hardwood

For wood, the EPA’s table says to remove the moisture immediately and dry with dehumidifiers, gentle heat and fans, using caution with heat on hardwood floors. Denali’s guidelines list what moisture gain can do to wood flooring, from discoloration and mold to cupping, crowning and buckling, which is a good reason to let boards dry before judging them.

Glued or nailed wood can’t come up in rows without damage. Chesapeake treats major damage as board replacement by a professional installer, tells owners to keep several planks for repairs, and requires water-damaged or delaminated subflooring to be replaced before a wood floor goes in.

Question 4: How long has it been wet?

The EPA’s rule of thumb is to dry water-damaged areas and items within 24 to 48 hours to prevent mold.

Its remediation guide treats materials wet for longer than 48 hours as possibly moldy, and adds two cautions: mold can grow even when things dry within 48 hours, and it won’t always grow after 48. The clock is a guideline, not a verdict.

Size matters too. For a moldy patch under about 10 square feet, roughly 3 by 3 feet, the EPA says most homeowners can handle the cleanup themselves. A lot of water damage, or mold beyond that size, sends you to its professional remediation guidance.

Question 5: Is the subfloor ready for a new floor?

Not until it is dry by the numbers the new floor’s manual sets. The EPA’s flooded-homes guidance says everything in the home must be completely dry before flooring is replaced, and Chesapeake’s Points East guide states that a subfloor that has been flooded or rained on may not be suitable for flooring at all.

Every manufacturer names its own moisture test and ceiling, and on a slab they differ by floor type; we lay them out in our guide to the best flooring for a concrete slab.

Before anything is torn out, photograph the floor, the water line on the walls and the source. The EPA’s flooded-homes page links to FEMA’s guidance on documenting flood damage for insurance claims.

The flooring warranties won’t carry this: PermShield excludes floods, plumbing and appliance leaks and other casualty events normally covered by homeowners’ insurance, and Chesapeake’s laminate and engineered warranties exclude damage from floods, plumbing or appliance leaks and standing water.

The first 48 hours, as a checklist to print

1. Stop the source and keep clear of electricity near the water.
2. Clean water or not? If not, call a professional and don’t run fans yet.
3. Photograph the floor, the walls and the source before removing anything.
4. Take up standing water with a wet vacuum, mop or towels.
5. Check underneath: lift a row of a floating floor at the wettest spot.
6. Dry with dehumidifiers and fans; go easy with heat on wood.
7. Write down when the water started and when drying began.
8. Old vinyl tile? Leave it for an asbestos professional.
9. Keep the spare carton, the receipt and the product name.
10. No new floor until the subfloor tests dry to the new floor’s limits.

Rebuilding: matching what stays

Partial repairs depend on matching. PermShield recommends keeping at least one full carton for future repair, Chesapeake recommends retaining several planks, and Denali allows up to 5% difference in color tone between production runs, so boards from your original carton will blend better than a new run.

If the water could come back, as on a ground floor in a flood zone, the floor and the way it is installed decide how much has to come out next time; that is the subject of our guide to the best flooring for flood-prone areas.

The quote for the rebuild depends on how much floor comes up, whether the original line and color are still available or a whole room has to change for continuity, and the moldings and transitions at the edges.

Once the subfloor has passed its test, send us the product name from your old carton or a photo of the floor, and we’ll check it against the SPC and laminate lines in our waterproof flooring collection.