Have you noticed your wood floor starting to buckle? Do you fear the worst? Before you decide to replace it altogether, read on.

We’ll cover the following;

  • What causes hardwood floors to buckle
  • How to fix water-damaged swollen wood floor
  • How to repair buckled hardwood floor
  • Care tips to prevent buckling
  • Alternatives

So, without any further ado, let’s dive;

What is Buckling

Buckling occurs when the wood floorboards swell and lift up from the subfloor, creating a noticeable hump, wave, or convex shape.

This problem is usually caused by excessive moisture in the wood, which can come from humidity, spills, refrigerator leaks, or flooding. 

When the wood absorbs too much moisture, it expands and pushes against the adjacent boards, causing them to rise up and buckle.

Why is my wood floor buckling?

Wood floors can buckle due to water damage or high moisture levels. When excess moisture is absorbed, the wood swells and loses shape, causing the floorboards to buckle or warp. Addressing the root cause of the moisture issue and repairing the affected areas can help prevent further buckling.

Signs of buckling wood floors

Several signs indicate buckling in wood floors. Here are some of the most common ones to look out for:

  1. Raised or humped areas: You may notice humps or waves in your wood floors, especially in the middle of the room or near the walls.
  2. Gaps or separations: The boards may separate from each other or from the walls, leaving gaps or cracks.
  3. Cupped floor: The edges of the boards may curl up or down, creating a cupping or crowning effect.
  4. Squeaking or creaking: The boards may rub against each other, causing a squeaking or creaking sound when you walk on them.
  5. Soft or spongy areas: The wood may feel soft or spongy to the touch, indicating that it has absorbed too much moisture.

 Differentiating buckling from other flooring issues

Buckling is relatively easy to identify, even for an untrained eye. 

Any raised areas on your hardwood floor buckling together, especially in the middle of a room, signifies hardwood floor buckling. 

You might also notice gaps between the boards or cracks in the wood.

Other Common Wood Flooring Issues

While buckling is a common wood flooring issue, it’s not the only one. Here are some other problems you might encounter:

  1. Cupping occurs when the edges of the boards start to curl up, creating a concave shape. Cupping is usually caused by moisture damage, such as spills or leaks.
  2. Crowning – This is the opposite of cupping, where the center of the boards starts to rise. Crowning can occur when the humidity level in the room is too low, causing the boards to shrink.
  3. Gapping – Occurs when there are noticeable gaps between the boards. This can happen due to seasonal changes or improper installation.

Now that we’ve covered some common wood flooring issues, how can you differentiate buckling from these problems? Here are some tips:

  1. Look for the location of the problem – Buckling usually occurs in the middle of a room, while cupping and crowning tend to affect the edges of the boards.
  2. Check for moisture damage – If you suspect your hardwood flooring issue is caused by moisture, look for signs of water damage, such as stains or mold.
  3. Consider the humidity level – If your hardwood flooring issue is related to humidity, monitor the humidity level in the room and make adjustments as needed.

Assessing the Damage on Hardwood Floors

We can evaluate the damage in three main steps

Evaluating the Severity of Buckling

Before you start any repair work, it is crucial to evaluate the severity of the buckling. Some minor buckling can be fixed easily, while severe buckling may require replacement of the entire board.

To evaluate the extent of the damage, you can use a straight edge or level to check the board’s surface. 

Place the straight edge or level perpendicular to the board and check for any gaps between the board and straight edge.

The gap can be sanded down if it is less than 1/8 inch. However, if the gap is more than 1/8 inch, the board may need to be replaced.

Determining the Affected Area

Once you have identified the severity of the buckling on damaged boards, the next step is to determine the affected area.

Check the surrounding boards to see if the buckling also affects them.

If the buckling is limited to one board, you can replace the board without affecting the surrounding wood plank or area. 

However, if the buckling has affected multiple boards, it is best to replace them to ensure a seamless repair.

Inspecting the Subfloor and Joists

After identifying the affected area, inspect the subfloor and joists for further damage. 

Inspect the subfloor and joists for any signs of water damage, such as mold or discoloration. 

Addressing the issue before replacing the boards is crucial if there is any water damage. 

Additionally, check for any damage to the joists, such as warping or bowing. If the joists are damaged, they may need to be replaced or reinforced to prevent future buckling.

Hardwood floors buckling causes

Here are the four main wood floor buckling causes

Excess Moisture and Humidity

One of the primary causes of buckling wood floors is excess moisture and humidity. 

Wood is a natural material that absorbs and releases moisture depending on its environment. 

When too much moisture is in the surrounding air, the wood absorbs it, causing it to expand. 

Conversely, when there’s not enough moisture, the wood releases it, causing it to shrink.

  1. Water leaks – One of the most common causes of moisture in the home is water leaks. Leaks can occur from plumbing, appliances, or even the roof. If you have a water leak, address it immediately to prevent long-term damage to your wood floors.
  2. Seasonal changes – Another cause of moisture and humidity changes is seasonal changes. During the summer, when it’s hot and humid, the wood will absorb more moisture, causing it to expand. In the winter, when it’s dry, the wood will release moisture, causing it to shrink. These seasonal changes can cause the hardwood planks to shift and buckle.

Prevention Tips:

To prevent floor buckling from humidity and excess moisture there are several things you can do:

  • Keep your home’s humidity level between 35% and 55%.
  • Fix any water leaks as soon as they’re detected.
  • Use a dehumidifier in rooms with high humidity levels.
  • Use proper ventilation in kitchens or waterproof the bathroom wood
  • Avoid using too much water when cleaning your wood floors.

   B. Installation errors

Improper Acclimation: Acclimation allows the wood to adjust to the temperature and humidity of its new environment before installation. Improper acclimation can lead to many issues, such as warping, buckling, and gapping.

Before installing your wood flooring or paneling, it’s important to acclimate it to the environment where it will be properly installed. 

This means storing the wood in the same room or area for at least 48 hours before installation. 

During this time, the wood will adjust to the temperature and humidity of the space, reducing the risk of warping or buckling during installation.

Insufficient Expansion Gaps: Wood is a natural material that expands and contracts as it absorbs air and releases moisture.

 If there isn’t enough room for this movement, it can cause the wood to buckle or warp. This is why it’s important to leave sufficient expansion gaps during installation.

The National Wood Flooring Association recommends leaving a gap of ⅜ inch between the perimeter of the hardwood flooring and any fixed objects, such as walls or cabinets. 

For larger installations, additional expansion gaps may be necessary.

Expansion gaps shouldn’t be filled with filler or sealant. Instead, use a color-matched wood filler to cover any gaps after installation.

Also Read: How to Reinforce Bed Slats

   C. Structural issues

Weak Subfloors: A subfloor is a material layer beneath your finished flooring, such as wood or tile. 

If the subfloor is weak, it can cause your finished product to warp or sag, leading to an uneven surface. This can be especially problematic when working on large projects, such as installing hardwood flooring.

To address a weak subfloor, you can reinforce it by adding additional layers of plywood or using a structural adhesive. 

Adding plywood to the subfloor can provide additional strength and support, while structural adhesive can help to bond the subfloor to the joists below. Ensure the subfloor is level and free from bumps or dips before installation. 

Uneven Foundations: 

Uneven foundations can cause buckling in wood through stress, moisture, and movement. When a foundation is not level, it can result in several specific issues that contribute to wood buckling:

  1. Uneven load distribution: An unstable foundation leads to unequal load distribution across the structure. This can cause certain parts of the wood to experience excessive stress, leading to compression and buckling.
  2. Warping due to moisture: Uneven foundations often lead to water pooling or accumulating moisture in certain areas. When wood absorbs moisture, it expands, and when it dries out, it contracts. This continuous cycle of expansion and contraction can cause wood to warp or twist, ultimately leading to buckling.
  3. Inadequate support: When a foundation is not level, it can cause gaps or uneven contact between the wood and the supporting structure. This lack of support can make the wood more prone to buckling under the applied load or over time as the wood undergoes natural aging.
  4. Compromised connections: Wood elements are typically connected to one another or to other materials via fasteners or adhesives. Uneven foundations can cause these connections to become stressed or misaligned, resulting in the wood elements moving or deforming, eventually leading to buckling.
  5. Differential settlement: If the uneven foundation causes differential settlement, meaning that different parts settle at different rates, the wood structure can be subjected to additional stresses. This can lead to twisting or bending of the wood members, ultimately resulting in buckling.
  6. Temperature-induced stress: Wood is sensitive to temperature fluctuations, and uneven foundations can lead to areas with varying temperatures. This can cause the wood to expand and contract at different rates in different areas, putting stress on the wood and potentially leading to buckling.

Read on plywood or solid wood for subwoofers.

Preventive Measures for Buckling Wood

Preventing buckling in wood is vital to preserving the structural integrity and aesthetic appeal of your flooring.

Let’s explore essential preventive measures you can take to safeguard your wood from the risks of buckling, ensuring a durable, stable, and visually pleasing surface for years to come.

Proper Installation Techniques

One of the most common causes of buckling wood is improper installation techniques. When installed incorrectly, wood can become stressed and distorted, leading to buckling and warping over time. 

To prevent this, it’s important to follow proper installation techniques, such as:

  • Ensuring that the wood is properly acclimated to its environment before installation
  • Using the correct fasteners and spacing them appropriately
  • Installing the wood with the proper orientation
  • Using the correct adhesive or sealant for the job

Controlling Moisture and Humidity

Another major cause of buckling wood is moisture and relative humidity alone. Wood is a porous material that naturally absorbs and releases moisture, which can cause it to expand and contract. 

If the moisture content of the wood becomes too high or too low, it can lead to buckling, warping, and other forms of distortion.

To prevent moisture-related problems, it’s important to control the humidity and moisture levels in your woodworking environment. This can be done by:

  • Using a dehumidifier or humidifier to maintain appropriate humidity levels
  • Storing wood in a dry, well-ventilated area
  • Sealing wood with a moisture-resistant finish (Here’s the best paint for flooring).
  • Avoiding exposure to direct sunlight and extreme temperatures

Regular Maintenance and Inspection

Finally, regular maintenance and inspection are essential for preventing buckling wood. 

Regularly inspecting your wood for signs of buckling, warping, or other forms of distortion, you can catch problems early and take corrective action before the damage becomes severe.

Regular maintenance can also help to prevent buckling by keeping your wood in good condition. This can include:

  • Regularly cleaning and dusting your woodworking tools and equipment
  • Applying a protective finish to your wood to prevent moisture damage
  • Storing your wood in a dry, well-ventilated area
  • Avoiding exposure to direct sunlight and extreme temperatures

Read Also: Why Are My Hardwood Floors Suddenly Slippery?

Buckling wood floors repair

Before you start to repair hardwood floor buckling, gathering the necessary tools and materials is essential. You will need the following:

  • Hammer
  • Pry bar
  • Utility knife
  • Sandpaper
  • Wood glue
  • Clamps
  • Replacement boards (if needed)

Clearing the Buckled hardwood floor

This is the first step in repairing buckled wood floors. Use a pry bar and hammer to remove any protruding nails or screws. If the screw doesn’t have a head, find out how to go about that in our article “How to get a screw with no head out.”

Carefully remove any damaged or buckled wood floors or boards and set them aside for later repair or replacement.

Repairing Minor Buckling

For minor buckling, there are two methods of repair: spot repair or weight application and clamping.

Spot Repair

To perform a spot repair, use a utility knife to remove any splinters or rough edges from the affected area. Sand the damaged area to make it smooth and apply wood glue to the underside of the buckled board. Press the board back into place and clamp it until the glue dries.

Weight Application and Clamping

For weight application and clamping, place a heavy object, such as a cinder block or weight plate on top of the buckled floor board. Allow it to sit for a few days until the board settles back into place. Use clamps to hold the board in place while it settles if necessary.

Moderate Hardwood Floor Buckling

Board replacement or reinstallation with proper expansion gaps may be necessary for moderate buckling.

Board Replacement

To replace a board, use a pry bar to remove the damaged board and cut a replacement board to size. Apply wood glue to the replacement board and slide it into place, securing it with nails or screws.

Reinstallation with Proper Expansion Gaps

If the buckling is due to improper expansion gaps, the boards may need to be reinstalled with proper spacing. Use a table saw to cut the proper expansion gaps and reinstall the boards with the appropriate gap size.

Handling Severe Hardwood Floor Buckling

Complete wood floor replacement or addressing underlying structural issues may be necessary in severe cases.

Complete Floor Replacement

Remove the hardwood floorboards and install a new subfloor to replace an entire floor. Install new flooring on top of the subfloor.

Addressing Underlying Structural Issues

If the floor buckling is due to underlying structural issues such as a warped joist or water damage, those issues must be addressed before replacing the flooring. Consult with a professional to determine the best course of action.

Recommended read: Wood flooring on walls ideas.

Handling severe buckling wood floor

Post-Repair Tips for Buckled Hardwood Floors

After successfully repairing buckled hardwood floors, it’s crucial to maintain their restored condition.

In this section, we’ll provide valuable post-repair tips to help you prevent future buckling, protect your investment, and ensure the longevity and beauty of your hardwood flooring for years to come.

A. Caring for Your Newly Repaired Wood Floor

  1. Keep the area clean and dry: sweep or vacuum regularly, and wipe up spills immediately.
  2. Maintain proper humidity levels (35-55%) using a humidifier or dehumidifier, and avoid extreme temperature fluctuations.
  3. Protect the wood surface by applying a protective sealant or finish, using felt pads or coasters under furniture legs, and considering area rugs in high-traffic areas.
  4. Inspect the wood floor regularly for wear or damage, and address issues promptly.

B. Monitoring for Future Issues

  1. Watch for signs of buckling: warped or lifted boards, gaps between boards, or a “hollow” sound when walking on the wood floor.
  2. Note any changes in wood appearance, like discoloration or unevenness.
  3. Inspect your home’s foundation for cracks or moisture intrusion, and check your plumbing system for leaks.
  4. Address moisture issues promptly: identify and fix the source of the problem, and ensure proper home ventilation to control humidity levels.
  5. Schedule routine maintenance for your wood floors, and consult a professional wood flooring expert if needed.

Alternative Flooring Options

A. Engineered Wood Flooring

Engineered wood flooring might be the perfect solution if you consider a more stable and less susceptible alternative to solid hardwood floors. 

Engineered wood consists of a top layer of real hardwood veneer bonded to a core of multiple layers of plywood or high-density fiberboard (HDF). This construction offers several advantages:

  • Increased stability: Less prone to expansion and contraction due to changes in temperature and humidity.
  • Easier installation: Can be installed using various methods, such as floating, gluing, or nailing.
  • Wide range of styles: Comes in numerous species, colors, and finishes to suit your preferences.

However, it’s important to note that the top layer of engineered wood is thinner than solid hardwood. This may limit the number of times engineered wood can be refinished after sanding.

B. Luxury Vinyl Planks (LVP)

Luxury vinyl planks (LVP) are a popular and affordable alternative to hardwood flooring. LVP comprises multiple layers, including a realistic printed vinyl layer and a wear layer for added durability. Some key benefits of LVP include:

  • Water resistance: Suitable for areas prone to moisture, such as kitchens, bathrooms, and basements.
  • Easy installation: Floating with a click-lock system is a great DIY option.
  • Low maintenance: Sweep or mop to keep the surface clean and looking great.
  • Comfort: Softer and warmer underfoot compared to hardwood or tile.

Remember that LVP, a synthetic material, may not offer the same timeless appeal and longevity as hardwood flooring.

C. Laminate Flooring

Another popular alternative to hardwood is laminated floors. This option features a high-resolution image of wood, stone, or tile, protected by a durable wear layer. Some reasons to consider laminate flooring are:

  • Budget-friendly: Offers a similar appearance to hardwood at a fraction of the cost.
  • Scratch resistance: The wear layer protects against scratches and dents.
  • Easy to install: Like LVP, laminate flooring often uses a click-lock system for simple floating installation.
  • Low maintenance: Regular sweeping or mopping is required to maintain its appearance.

However, laminate flooring is not as water-resistant as LVP, so it’s not recommended for areas with high moisture levels.

When choosing an alternative flooring option, consider factors such as budget, maintenance, durability, and the specific needs of your home.

Read More: How Do You Remove Black Urine Stains From Hardwood Floors


Should I hire a professional to fix my buckled wood floor?

While a homeowner can fix minor buckling in a wood floor, more severe cases may require professional assistance. A professional will have the knowledge and tools to solve the issue completely.

How long do wood floors last?

The lifespan of wood floors depends on maintenance and foot traffic, with some lasting over 100 years. Hardwood floors are more durable, while softwood floors are less so. Regular cleaning and refinishing can extend the life of wood floors.

How much does it cost to fix buckled wood floors?

The cost to fix buckled wood floors varies from $300 to $1,000, depending on the extent of the damage and type of flooring. Repairs to buckled floors may include sanding, refinishing, or replacing affected boards.

What is the difference between buckling and cupping?

Buckling occurs when floorboards lift from the concrete subfloor in humid weather, while cupping is when edges curl upwards due to humidity. Both can be prevented by maintaining consistent humidity and temperature levels.

How to fix water damaged swollen wood floor?

To repair a water-damaged swollen wood floor, start by allowing it to dry. You can also use electric fans to facilitate the drying process. Another option is to use a needle or printer to remove water bubbles. Once the wood is completely dry, evaluate the damage and sand the wood, apply furniture oil, and flatten the surface.

Why is Wood floor buckling in winter?

Wood floors can buckle in winter due to changes in temperature and humidity levels. As the air gets colder and drier, the wood loses moisture and can shrink, causing gaps to appear between the boards. However, when the heat is turned on indoors, the air becomes warmer and more humid, causing the wood to absorb moisture and expand. This cycle of contraction and expansion can lead to buckling floorboards.

Will buckled floors go back down?

Whether or not buckled floors will go back down depends on the severity of the buckling and the underlying cause. Minor wood floor bowing up may resolve on its own as moisture levels stabilize, but more severe buckling will require intervention. Addressing the root cause of the buckling, such as moisture or water damage, and repairing or replacing the affected boards can help restore the flooring to its original state.

Can you fix warped wood flooring?

Yes, warped wood flooring can be fixed. Warped hardwood floor repair solution depends on the severity of the warping and the underlying cause. For minor warping, sanding and refinishing the floor may be enough. However, severe warping caused by moisture or water damage may require replacing the affected boards and addressing the root cause. Here is more on how to unwarp wood.

What do I do if my wood floor starts to buckle

If your wood floor starts to buckle, address the issue promptly to prevent further damage. The first step is to identify the cause of the buckling, which could be due to moisture or water damage. Once you’ve identified the cause, you can take steps to repair the damaged areas. This may involve drying out the affected areas, sanding and refinishing the wood, and replacing damaged boards.

Related read: How to cut wood panels without splintering

How to fix buckled wood floor summary

In conclusion, fixing a buckling floor often requires addressing the underlying issues, such as incorrect subfloor construction, that may have contributed to the problem.

To restore the wooden boards and planks to their original shape, it is essential to identify and rectify any defects in the subfloor or foundation. This may involve leveling the foundation, improving drainage and moisture control, or replacing damaged materials.

Proper care should be taken while reinstalling the wooden boards and planks to ensure a stable, even, long-lasting flooring solution.

By addressing the root causes and applying appropriate remedial measures, homeowners can prevent further buckling and enjoy a safe, comfortable, and aesthetically pleasing floor