Sagging or Uneven Floor Sagging sections in your flooring are an immediate, telltale sign that you have major issues with the subfloor. Flooring problems of this nature are almost always caused by moisture, but they can also indicate poor installation.
Your floors shift or bounce when you walk on them.
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.
Signs may include loose flooring pieces or a floor that is undulating and uneven in areas. Wet or water-damaged subfloors that are structurally unstable can cause long-term problems with your home, and simply replacing the wood floor on top will not fix the problem.
There are many factors that can affect its longevity, such as the material, the amount of moisture it's exposed to, etc. However, most subfloors can last as long as the home itself. That said, you may have to replace your subflooring after 20 to 30 years if it has absorbed too much water too often.
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.
Replacing subflooring is a relatively complicated task that requires precise measurements. You'll need to make sure all of the parts of your floor are structurally sound. That said, you don't always need to replace the entire subfloor. If only a portion is damaged, you can patch it.
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.
Subfloor mold can appear as dark spots or patches beneath flooring materials like carpets, vinyl, or laminate. It often grows on plywood or OSB substrates, common since the 1950s. The presence of subfloor mold can be hinted at by a musty odor.
Does homeowners insurance cover subfloor? In general, homeowners insurance covers subfloor water damage. However, it must be caused by one of the perils listed in your insurance policy.
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.
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 most obvious is a spongy feel or “give” to the affected area. Other signs of water damage include warping in the floorboards of your hardwood floors, loose sections in your tile floor, bubbling or peeling in linoleum, lifting in your laminate flooring, or a musty smell that could indicate mold growth.
As previously mentioned, the labor cost for subfloor replacement varies depending on factors like room size and location within the house. Typically, it ranges from $25 to $30 per hour. The project duration usually spans a day or two but can vary based on the extent of repairs and necessary prep work.
The subfloor is typically made of plywood or OSB, ranging from 19/32 inches to 1-1/8 inches thick. Subfloor plywood or OSB sheets typically have tongue-and-groove edges to reduce floor sagging and bounce. If the bottom-most floor is a concrete slab, its definition as a subfloor becomes more fluid.
Foundation damage caused by shifting or settling earth or sagging floors caused by rotting floor joists are typically not covered by homeowners insurance. If the damage is caused by flooding or an earthquake, you'll typically require separate coverage.
Your gut tells you something is wrong, but how do you know if floor joists are bad? Some telltale signs include rotting wood, skewed and unlevel or hard-shutting window frames and doors, sinking crawl space supports, and cracks in interior drywalls.
Choosing between repairing and replacing subflooring comes down to the condition of the existing subfloor. If it's generally in good shape, repairing the damaged areas may be a consideration and can cost less than a full replacement. Subfloor repairs can cost between $2 and $10 per square foot.
One of the most common reasons for soft spots is moisture infiltration. Water can seep into the subfloor or flooring material through leaks, spills, or high humidity, causing the wood or materials to rot, warp, or weaken.
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.
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.
Special considerations must be made to prevent the walls from sagging or hanging down while the subfloor is not in place to support them. Smaller subfloor sections—up to about 14 inches wide between joists—can be cut out and replaced without needing extra support.
Typically, wood joists have the cross section of a plank with the longer faces positioned vertically. However, engineered wood joists may have a cross section resembling the Roman capital letter "I"; these joists are referred to as I-joists.