Cupping or Warping Warping and cupping are tell-tale signs of a weak subfloor and may indicate water damage. Cupping means your floorboards have curls along the board's length, and it's caused by moisture. Warping means that the floorboards twist out of shape like an “S.” It is also often caused by water.
If your floors begin to feel spongy, springy or bouncy, or if you notice the floorboards around you shifting when you walk on them, it could mean that it's time to replace your subfloor.
Sagging or Uneven Floors: A Clear Indicator of Structural Issues. Another critical sign that your subfloor may need repair is if you notice sagging or uneven floors. These issues are often more apparent in certain areas of the home, such as near doorways, in the middle of rooms, or along walls.
The hollow/spongy patches aren't caused by sagging. The floor is trying to expand, but is being pinched at the edges because there's not an adequate expansion gap where the floor meets the walls, so it buckles upwards.
The only way to make this repair is to reinstall the flooring with the proper underlayment. This should be done by a professional and done as soon as possible to reduce the possibility that the floorboards themselves will become damaged.
Mold can quietly spread in these hidden areas, especially where there's moisture and organic matter. To find subfloor mold, look for musty smells and check for visual signs. Discoloration and damage to flooring materials are often signs of a bigger problem that needs attention.
Signs of termite damage
If termites start to snack on your home's joists or subfloor, you might notice sagging floors — or hear them creak more than usual as you walk on them. Similarly, termites eating away at wall studs and ceiling beams could cause the ceilings and walls to buckle.
Generally, no. Insurance would cover a sudden loss event. A slow leak causing rot over an extended period of time is not a sudden loss event.
Given the complexity of subfloor repairs, you should really stick with a carpenter for this project. But if you want to install a new subfloor or underlayment over sound floor joists, hire a local flooring contractor for this step.
The first way that you can fix a subfloor moisture problem is by removing the finished floor and exposing the subfloor. Make sure that an HVAC system is installed or use a dehumidifier, and then, let the subfloor dry until the moisture levels have gone down.
A common sign of compromised joists is uneven floors. But these could be the result of flooring or subflooring defects. “Bouncy” floors are a very common sign of rotten floor joists. A musty or damp smell in certain rooms of your house is a clue to the presence of mold or decay.
Check the Level of the Subfloor
To check for small high or low spots that may not even be visible, place a long level or straight pipe on the subfloor. Move it around to different areas and mark any high or low spots you find with a pencil or marker. Most floors will have at least some slight variations.
This can be a potential source of bacteria and odors, and it is best to remove and replace the flooring and subfloor material completely. Waterproof flooring typical refers to floors that are unlikely to swell or warp due to water damage (usually as long as it is dried up within 24 hours.
Borax is highly recommended as a mold remediation product.
Subfloor Cost per Square Foot
Subfloor replacement typically costs about $3 to $10 per square foot. This range can vary based on labor costs, which will add $25 to $30 per hour, and the type of subflooring you choose.
Homeowners insurance doesn't usually cover mold damage or removal unless it's the result of a covered peril. If the mold in your residence was caused by something sudden or accidental, such as a bursting pipe or some other covered incident on your policy, you may be protected.
There are many signs that your damaged subfloor should be replaced with a new subfloor. These include squeaks and other noises, cupping or warping, cracked or popped tiles, sagging or unevenness, the smell of mold or mildew, or bubbling tile.
Taking all these factors into account, subfloor material costs can range from as low as $2.50 per square foot for plywood to as high as $10 per square foot for Amdry or Barricade. Common subfloor materials include plywood, oriented strand board (OSB), Amdry, DRIcore, Barricade, Warmboard, and concrete.
Signs of Mold under Hardwood Floors
You might notice patches of discoloration (usually black or green, although mold can grow in a variety of different colors) with a slimy or fuzzy texture. Other times, mold isn't so easily seen if it's growing under the floorboards, on the floor joists, or on the subfloor.
Causes of Bouncy Floors in Your Home
Over Spanned Joists: Joists supporting floors above crawl spaces may be spaced too far apart or be too long, causing excess flexing. Inadequate Support: Insufficient support structures like poorly installed or shifted posts and beams can lead to bouncy floors.
In most cases, damaged subflooring doesn't need to be replaced. However, in the event of extensive water damage from flooding or extended periods of exposure to moisture, damaged sections may need to be removed to avoid mold and ensure structural integrity.
An uneven subfloor is most likely to be the culprit for that spongy feeling if the issue is not evenly distributed but confined to specific areas – particularly if you can rule out causes such as water damage if, for instance, the flooring is newly installed.