Subfloor Repair and Water Damage Flooring in Burlington, NC

What is a subfloor, and why does it matter?

The subfloor is the structural layer your finished floor sits on. It’s fastened to the joists and carries the weight of everything above it. Houses from the early and mid-1900s often have board subfloors, nailed down in strips or on a diagonal. Later houses usually have plywood or OSB panels, typically 5/8 to 3/4 inch thick.

It matters because every floor depends on it. Tile cracks when a subfloor flexes. Vinyl planks separate over dips. Hardwood squeaks and cups over damp wood. A thin layer of underlayment on top is not the same thing as the subfloor, and it can’t make up for a weak one.

What are the signs of a damaged subfloor?

• A soft, spongy or bouncy spot underfoot
• A room that slopes or feels like it’s sinking
• Squeaks that come with movement or soft spots
• Cracked tile or grout, or planks that keep separating
• Boards that cup or lift
• A musty smell, or stains and discoloration near walls, toilets, tubs or appliances
• Visible mold or dark, soft wood at the edge of a floor

One sign alone doesn’t tell you much. A soft spot near a toilet or dishwasher tells you a lot.

What causes subfloor damage in Burlington houses?

Almost always water, over time or all at once. The common causes in this area:

• Slow leaks. Toilet and tub drains, supply lines, dishwashers, washing machines, ice-maker lines and water heaters.
• Crawl-space moisture. About half of Burlington’s homes were built in 1978 or earlier, and many sit on crawl spaces. Humid air condenses on cooler joists and subfloor, and bare dirt or standing water makes it worse.
• Air conditioner drain overflows. A plugged condensate line can spill onto a floor or into a crawl space.
• Roof and window leaks during storms. The National Weather Service put severe thunderstorm warnings over Burlington on July 20, August 17 and August 22 in 2026, each with 60 mph gusts.
• Flooding. In July 2025, Tropical Storm Chantal pushed the Haw River to 32.5 feet, its second-highest crest on record, and homes in Alamance County that had stayed dry for decades flooded for the first time.
• Wood-destroying insects, which go after damp wood first.

Why does one room feel like it’s sinking?

A single sinking spot is often rotted or loose subfloor, usually from a leak. A whole room that has dropped is more serious and often structural: a settled pier, a sagging beam, a rotted joist or a wall removed without proper support. Both need someone to look at the framing, not just the surface.

We open the area up, probe the wood with a screwdriver, check it from the crawl space where there is one, and meter the moisture. Soft wood is rotted wood. If the problem is the structure, we say so and recommend a structural contractor before any flooring work.

Can a subfloor be repaired, or does it have to be replaced?

Most of the time, a damaged section can be cut out and replaced. A full subfloor replacement is rarer. What we do depends on how far the damage goes:

• Replace the damaged section with subfloor of matching thickness, glued and screwed to the joists
• Add blocking or reinforce joists where the framing is weak or the span flexes
• Patch board subfloors in older houses with matching boards or plywood, keeping the surface even
• Fasten loose panels with screws instead of leaving them to squeak and shift

We replace and reinforce what’s damaged. If the framing itself is rotted or has failed, we’ll tell you and point you to a carpenter or structural contractor first.

What should you do with the floor after a leak or flood?

Stop the water, document it, and get the subfloor dry, in that order. Health agencies advise drying a flooded home within 24 to 48 hours, because mold can start growing in that window. Floating planks can often be lifted so the subfloor can be seen and dried. Then it’s metered, soft sections are replaced, and only then does the new floor go down.

The full walkthrough is on our waterproof flooring page. Flood water carries contaminants and a large patch of mold calls for a licensed restoration company, and we’ll tell you when that’s the right first call.

How do you level an uneven floor?

It depends on what’s causing the dip. Cosmetic unevenness can be fixed. A structural dip can’t be fixed with filler.

• High spots on wood subfloors get sanded or planed down
• Low spots get filled with a leveling compound or patch, or built up with underlayment
• Concrete slabs use a self-leveling underlayment
• Joist dips from below can be shimmed or blocked, which is the real fix when the floor itself has dropped

Most floating floors want a subfloor flat within about 3/16 inch over 10 feet, and some makers specify 1/8 inch over 6 feet. Your product’s instructions have the exact number.

Why do floors squeak, and can it be fixed?

Most squeaks come from loose subfloor panels moving against nails or joists. They can often be fixed from below, with screws, shims or adhesive, or from above, with trim-head screws driven into the joists. Humidity swings that make wood shrink and swell can cause seasonal squeaks too. A squeak on its own is an annoyance. A squeak with a soft spot or a sag is worth looking at.

How do you know the moisture problem is fixed before new flooring goes in?

By measuring, not by feel. Dry to the touch isn’t dry. We meter the subfloor, check the crawl space and the source of the moisture, and compare the readings to what the flooring maker requires. For wood floors, the common standard is a wood subfloor under about 12 percent moisture and within roughly 2 to 4 percent of the flooring. Vinyl and laminate makers publish their own limits. If readings are still high, the floor waits.

What about termites and other wood-destroying insects?

If we find signs of termites or other wood-destroying insects, such as mud tubes, hollowed wood or frass, we stop and tell you to call a licensed pest professional. Framing repair comes after the insects are dealt with, not before.

Does insurance cover subfloor damage?

Standard homeowners policies don’t cover flood damage. That takes a separate flood policy. Sudden water from inside the house, like a burst pipe or a failed appliance, may be covered depending on your policy. Slow leaks and long-ignored moisture usually aren’t. Call your insurer early and keep photos and moisture readings. We repair floors, so we can’t tell you what your policy covers. Your agent can. FEMA’s FloodSmart.gov explains flood coverage.

What does a subfloor repair job look like from start to finish?

1. We come look. We check the surface, probe the soft areas and talk through what you’ve noticed.
2. We find the source. A moisture meter, a look from the crawl space where there is one, and the usual suspects: plumbing, drains, roof and ground water.
3. You get a written price. Repair, replacement, any reinforcement, flooring, trim and transitions, each on its own line.
4. We stop the cause and dry it. The leak or moisture source gets fixed, and the wood gets dried.
5. We repair the structure. Damaged sections come out, new subfloor goes in with matching thickness, and loose panels get fastened.
6. We verify, then install. New readings first, then the new floor.

Where do you repair subfloors near Burlington?

We repair subfloors and replace water-damaged floors across Burlington, from older houses off South Church Street to newer neighborhoods near Alamance Crossing, and throughout Alamance County.

Town	ZIP code	What matters there
Burlington	27215, 27217	Older houses on crawl spaces, board subfloors and slow leaks
Haw River	27258	The town closest to the river that crested at 32.5 feet in July 2025
Graham	27253	Older and newer homes with the same moisture checks
Mebane	27302	Newer homes, where leaks and storm damage are the usual causes
Elon	27244	Rentals and family homes near Elon University
Gibsonville	27249	Homes on both sides of the Alamance and Guilford county line

More subfloor questions

Can I put new flooring over a soft spot?

No. A new floor over a soft or damp subfloor will squeak, flex and fail early, and it can hide rot and mold. The soft section gets opened up, the cause gets fixed and the wood gets replaced first.

Is a squeaky floor a structural problem?

Usually not. Squeaks are most often loose subfloor panels rubbing on fasteners or joists, and they’re fixable. A squeak together with a soft spot, a sag or a musty smell is worth a closer look.

How do you find a leak under a floor?

By following the moisture. A moisture meter, a look from the crawl space, and checking the usual suspects, such as supply lines, drains, the water heater and the AC drain, find most leaks. A plumber fixes the leak itself.

Is a sagging floor a foundation problem?

Sometimes. A dip in one spot is often rot or a loose subfloor. A whole room that has dropped can mean settled piers or a damaged beam or joist. We’ll tell you when it’s a job for a structural contractor.