
How to fix hardwood floor cupping
- Make sure you have a reliable wood moisture meter so you know how much the wood moisture content has risen or can identify wet problem areas. ...
- Determine where the moisture is coming from. As referenced above, is the cupping uniform and seasonal? Is it confined to one area? ...
- Get a dehumidifier, especially if you have a basement or an area of the house that tends to be more humid than other areas. ...
- Maintain your floor properly, using the right cleaning methods and products made specifically for wood floors. ...
- After a significant leak or spill, especially if water or other liquids have had time to absorb into the floor and subfloor, you may need to contact the professionals for ...
How to remediate a cupped wood floor?
Should You Sand Down Cupped Hardwood Floors?
- Emptying the Room. Sanding involves minute dust particles being released in immense quantities into the air, and they may permeate your curtains, rugs, or upholstery if they are left ...
- Preparing the Room. Once the room has been emptied, you will need to seal every entrance and aperture with tape and plastic sheeting.
- Starting the Sanding Process. ...
How to keep wood floors from popping?
- between 12 and 16 fasteners per square foot on a 3″ wide plank;
- between 6 and 8 fasteners per square foot on a 6″ wide plank; and
- between 3 and 4 fasteners per square foot on a 12″ wide plank.
Why are my hardwood floors cupping?
What are the common causes of cupping in flooring?
- Subfloor moisture. If there is excess moisture in the concrete slab, crawl space, or basement below your wood floor, this can cause cupping.
- Leaks or spills. Cupping due to leakage will usually be confined to areas around sinks, dishwashers, etc. ...
- Improper care/cleaning. ...
- Improper installation. ...
How to fix door that scrapes floor?
- Make sure you use a screwdriver that properly fits into the screws. ...
- You can check for loose hinges and screws by opening the door halfway and pulling the handle straight up. That way, you can see which hinges move around.
- If the screws don’t stay tightened because the holes are stripped, keep reading on for a simple fix.

How do you fix cupping hardwood floors?
To truly fix it, you must get to the source of the water damage. Once you've addressed that, you can try to get your wood floors back to their original beautiful state. For minor cupping, the fix might be as simple as returning the room to its normal humidity levels with a dehumidifier.
Will cupped hardwood floors flatten?
In some cases, if the cupping was not severe the flooring may flatten to an acceptable level with minor gapping after drying. Remember the flooring has lost moisture so some shrinkage will result. Before any repair or remediation the flooring should be checked for looseness.
Can cupped wood Be Fixed?
In many cases, if cupping isn't severe, the issue can be fixed once the moisture issue is fixed. Since the process of cupping is the wood reacting to moisture, if the wood's moisture level returns to the proper equilibrium, the cupping can resolve.
Can you sand down cupped hardwood floors?
DO NOT sand a cupped floor. Sanding a hardwood floor while it is still cupped will result in a problem called “crowning.
How do you get moisture out of hardwood floors?
Use a dehumidifier placed at the highest setting possible to dry the floors. Place it in the center of the room and leave it on for at least 24 hours. Next, place fans around the room so the entire surface receives the blowing air. Place the fans at the highest settings possible.
Can water damaged hardwood floors be fixed?
Depending on the severity of damage, the hardwood floors may only need to be refinished. In some cases patching is required to replace the damaged boards prior to refinishing. In the worst case scenario, the entire floor needs to be removed and replaced.
Will warped floors go back to normal?
Cupped flooring looks bad but it's almost always reversible. It can usually be corrected by simply restoring proper humidity inside the room, which will help balance out the moisture above and below the flooring.
Will buckled floors go back down?
If the buckling is only minor, in many cases the boards might return back to normal. If the boards are still showing areas of damage and buckling, you'll need to replace them.
Will warped wood go back to normal?
Applying additional moisture and heat to the opposite side of the warp can cause the wood to warp back into its original flat position, effectively “unwrapping” the piece. Minor warping can usually be corrected with heat and moisture only, but for more severe warping, you may also need to apply pressure to the wood.
How do you flatten cupped boards?
0:161:41How to iron a warped/cupped board flat again! - YouTubeYouTubeStart of suggested clipEnd of suggested clipYou can also remove a cup by adding moisture to the concave side try putting a damp cloth on theMoreYou can also remove a cup by adding moisture to the concave side try putting a damp cloth on the surface. And then use an iron you can actually steam. The cup away.
Is hardwood floor cupping permanent?
As long as the wood is not permanently deformed or damaged, the flooring should return to its original shape and size when it returns to its original moisture content. This process may take weeks, months or even an entire heating season.
What causes hardwood floors to Cup?
Excess moisture is the culprit when it comes to hardwood cupping. This happens when the humidity level is high, when the boards absorb too much moisture from the subfloor, from water leaks and spills or even by cleaning your hardwood flooring in the wrong manner.
Will warped floors go back to normal?
Cupped flooring looks bad but it's almost always reversible. It can usually be corrected by simply restoring proper humidity inside the room, which will help balance out the moisture above and below the flooring.
Can buckled hardwood floors be repaired?
When it comes to buckled hardwood flooring options, the good news is that your floor might not need a major repair job. A buckled floor with only minor damage can sometimes be repaired simply by removing the excess moisture, but serious buckling will necessitate replacing the hardwood boards.
How long does it take for hardwood floors to Cup?
It is not hard to see the effect in wood flooring, either. For many species and aspect ratios, a piece of flooring placed on a towel that is kept moist will show some cupping in a day or two. Very noticeable cupping will occur within a few days.
Why are my new hardwood floors cupping?
Excess moisture is the culprit when it comes to hardwood cupping. This happens when the humidity level is high, when the boards absorb too much moisture from the subfloor, from water leaks and spills or even by cleaning your hardwood flooring in the wrong manner.
Why does cupping happen?
In short, moisture. Wood, even when it’s treated and sealed, is still a porous, fibrous material. It can still react with the moisture content (MC) in the air around it. Materials like wood will balance (equilibrate) its MC with its surroundings, similar to the principle of osmosis.
Why is my floorboard cupping not going away?
If the cupping in the floorboards doesn’t go away, it could mean that the underlying moisture issue was not properly addressed and still needs some attention. While cupping can remain after a severe event like flooding, persistent cupping is worth investigating.
What happens if you put hardwood floors in before they dry?
Improper installation. If a hardwood floor is installed before a subfloor is properly dried, or before the floorboards reach an equilibrium moisture content (EMC), such as before the inside of a building’s air is conditioned, there is a chance for cupping later on. As furniture and people begin to inhabit the area, it will bring about a new level of moisture and temperature to the air. You want to ensure that moisture levels between the subfloor and the finished floor have reached proper EMC for the long-term. And to make absolutely sure the moisture readings are optimal for beginning the installation, you want the most accurate moisture measurement tools possible.
What does cupping look like on hardwood floors?
What does cupping look like on a hardwood floor? When moisture interacts with a hardwood floor, the side of the boards closest to the moisture expands. This expansion can be in the form of cupping (the center of the board is lower than the edges) or crowning (the center of the board is higher than the edges).
Why is my house cupping?
If cupping is happening in a relatively uniform manner throughout your house, and the degree of cupping is not drastic, this is likely the cause. Subfloor moisture. If there is excess moisture in the concrete slab, crawl space, or basement below your wood floor, this can cause cupping.
Why does my wood floor warp?
It can happen to most types of wood, and it’s often the first observable sign your floor is being affected by moisture. Since wood reacts to moisture so easily, floorboards can warp as they react to the change in their internal moisture content (MC) after the floor’s installation.
Why does wood shrink when dry?
If the air is dry, wood fibers will release some of its moisture back into the air and it can shrink back down. It’s most common for moisture to enter the floorboards from below, through the subfloor. This is why the bottom of the board swells and makes the edges curve upward into an almost wave-like pattern.
How to stop chatter marks on hardwood floors?
bearings are common issues that could produce chatter marks on hardwood floors. The best way to prevent chatter marks is to make sure your big sander is operating perfectly. You may have to take it to a repair shop to have it serviced. If there are already chatter marks on your floor one great way to fix them is by using a multi-disc sander like ...
Why is my floor cupped?
Typically, cupping is a problem that stems from excessive moisture. Anything from pipe leaks to a still-wet concrete slab to improper HVAC usage can cause cupping. Wood is hygroscopic, meaning that it absorbs and releases moisture. When one side of the floor is exposed to excessive moisture, that side will expand, causing the whole board to warp away from that side. The sides of the boards curl up, resulting in the characteristic “U” shape of a cupped floor.
What is a chatter mark on a floor?
Chatter marks are repeated imperfections on the floor that are between 1/2″ and 3/4” apart. They are traditionally caused by some sort of failure in the big machine sander. Bad sandpaper. A multi-disc sander like the Lagler Trio can help you get rid of chatter marks.
How to fix cupping?
To fix the issue of cupping the first and most crucial step is to assess the moisture problems. Take the necessary steps to stop or correct the source of the moisture problem. Certain issues that can cause cupping include wet mopping the floor, plumbing leaks, a damp subfloor, and the environment fluctuating outside of a range of relative humidity ...
Why does my wood floor make a noise?
If the floors were installed with improper nailing schedules or the incorrect adhesive, they will be loose and cause noise. If the subfloor is inappropriate for the wood floor being installed that could also be the cause the noise or movement.
What does it mean when a floor is cupped?
Cupping means that the wood that is raised on the edges of each individual floor board. The center of the board dips below the edges. This makes the wood appear to be in a “U” shape. (See the picture at the top of this post for an example of a cupped floor.) Typically, cupping is a problem that stems from excessive moisture.
What are the problems with hardwood floors?
Here are some of the most common problems that occur while installing hardwood floors––including cupping, crowning, and squeaky floors– –and instructions on how to fix them.
How to sand urethane?
Scuff the surface of the urethane lightly using a long-handled pole sander loaded with 120-grit sandpaper. Vacuum the floor.
How to sand around the edge of a room?
Sand around the edge of the room and areas that the floor sander misses with a handheld orbital sander with 40-grit sandpaper attached. Tip the sander slightly to remove finish from deeper cups, if necessary.
How to apply urethane to a floor?
Pour some urethane finish into a painter’s pan or small tub. Dip a long-handled lamb’s wool applicator into the finish and apply it to the floor, working with the grain. Set the applicator on a piece of dry floor and push it into an area where you have applied the urethane. By maintaining a wet edge, your brush strokes with the applicator won’t be visible. Cover the entire floor with the urethane and let it dry overnight.
How to know if wood is finished drying?
It may take an entire heating season for the wood to relax so most of the cupping disappears. A difference of 1 percent between the top and bottom of the hardwood floor planks indicates they are not finished drying.
How long does urethane take to dry?
Add the final coat of urethane with a paintbrush. Do not overlap strokes or brush marks may be visible. Allow the urethane to dry for three days before cleaning the floor and reattaching the shoe molding with brad nails.
How to remove scratches from a floor?
Attach 50-grit sandpaper to the floor sander and to the orbital sander. Go over the entire surface of the floor again. This pass with the sandpaper should remove any scratches as well as the remainder of the high places caused by the cupping. Change the sandpaper, as necessary, to get a uniform surface. Vacuum the floor again.
Why do planks contract?
The planks that make up wood flooring expand and contract based on the amount of moisture in the room. Whenever there is too much moisture, the wood expands, forcing the planks together until their centers bend downward and form individual valleys or cups. In rooms that are temperature-controlled, you are less likely to see this problem.
What type of flooring is the most popular?
The most popular type of flooring in most homes today is hardwood flooring. Over time, hardwood floors can become damaged from the wear and tear of day-to-day use. If you have damage to your wood flooring, you may be considering replacing it with something new. But before deciding on a replacement option, you might want to consider fixing your existing wood floors instead.
Why does my wood cup?
Cupping is a natural occurrence and in most cases, it's simply the result of moisture damage. Many hardwoods are quite porous and will naturally cup when there's water damage. Where we live, in Georgia, the climate is very humid most of the year. This alone can lead to cupping and buckling wood floors.
How long does it take for a floor to dry?
Then we begin drying. To dry a floor completely can take anywhere from a few hours to a week or more, depending on the extent of the damage and size of the affected area. We place fans and air movers throughout the area. To speed up drying, high-powered industrial dehumidifiers are also used. In some cases, we use an Injectidry vacuum drying unit. This reduces the time it takes to dry particularly difficult areas of your floor.
Why is moisture important in wood?
The moisture content of wood is also significant because it can be a sign of underlying water damage or mold. We use moisture meters to test for the moisture content of the floors. A moisture meter can be used to determine what stage the floor is at if there might be a nearby leak or any potential for mold growth.
Can you refinish a cupped floor?
Many times, all that’s needed is drying to restore cupped floors. However, sometimes the floors need to be sanded and refinished. This is the same procedure used when your floors were originally installed. Hardwood floors can be sanded and refinished several times over the course of their life. Sometimes, after sanding heavily cupped floors, we may also use a leveler or sealant to further protect them against more damage in the future.
Is floor damage expensive?
Floor damage can be expensive, time-consuming, and stressful for a homeowner to deal with. We’re on call 24/7 to help with any kind of floor damage, whether it’s water, fire, or mold. We help our customers know how to effectively negotiate with their insurance company to make sure everything is taken care of!
How does cupping work on hardwood floors?
The expansion can take the form of crowning (the center is higher than the edges) and cupping (the board’s center is lower than its edges ). Both are due to moisture imbalance in boards.
What are the common causes of cupping in flooring?
Change in the amount of moisture in the air (relative humidity). Your wood floor may react to changing humidity levels if it is located in an area that experiences dry winters or humid summers. Wood floors expand and contract in each season. Cupping may occur in a fairly uniform manner throughout your house. The degree of cupping should not be too drastic.
Why is my floorboard cupping?
If the cupping in the floorboards doesn’t go away, it could mean that the underlying moisture issue was not properly addressed and still needs some attention. Cupping may persist after flooding or other severe events, but persistent cupping should be investigated. It is important to avoid prolonged moisture problems as they can cause many flooring failures.
What happens if you put hardwood floors on before they dry?
Improper installation. If a hardwood floor is installed before a subfloor is properly dried, or before the floorboards reach an equilibrium moisture content (EMC), such as before the inside of a building’s air is conditioned, there is a chance for cupping later on. The area will become more humid and warmer as furniture and people move in. For the long-term, you want to make sure that the moisture levels between the subfloor floor and the finished floor are at the right EMC. You will need the most precise moisture measurement tools to ensure that your moisture readings are accurate for starting the installation.
What is a wood moisture meter?
A wood moisture meter is an accurate tool to detect moisture problems in hardwood flooring and prevent cupping.
Why does my basement have a cupping?
Subfloor moisture. Cupping can occur if there is too much moisture in your concrete slab, crawlspace, basement, or below-floor wood floor. This can happen especially in new construction, especially if the floor was installed before any HVAC system is connected to your home. This can also happen if the humidity is higher in your crawl space or basement.
Why is my wood floor warping?
Once again, the moisture issue that caused the cupping is not being addressed. If the cupping was caused by humidity, such as from a particularly wet summer, and you sanded the area that is affected, the wood may warp when the air drys out, leading to crowning.
How to fix cupping in hardwood floors?
If you notice cupping in your hardwood, start by locating the source of the moisture and fixing any issues, such as cracked pipes. Once the underlying problem is fixed, dry the area entirely, using industrial-grade tools, and sand down any residual raised areas.
How to control humidity in a house?
A dehumidifier is an excellent way to control your home’s humidity levels. If the moisture damage is minor and the cupping is minimal, a dehumidifier may be enough to fix the problem. While it is working to remove the air’s moisture, keep the doors and windows of the affected room closed, and run the air conditioning if possible to prevent excess humidity from entering in warmer months.
Why is my wood floor tripping?
As the wood boards’ sides now sit higher than the center, the floor will become a tripping hazard. Cupping will occur when the underside of the hardwood becomes exposed to moisture. Cupping is usually a sign of a water leak from pipes or even appliances, such as a refrigerator.
Why does wood crack in winter?
As mentioned above, cupping can occur when the hardwood is exposed to hot, humid temperatures in the summer and then cooler winter temperatures. This will cause the wood to expand and contract, allowing moisture to enter the cracks between boards.
Why do you need an underlay on carpet?
For carpet, an underlay may be thick to provide extra padding and also helps to prevent moisture from affecting the top layer.
What is a moisture meter?
Meter-Test for Moisture. A moisture meter is an instrument used to detect the moisture content in building materials. When you believe you have a leak, you can use such a device to check your floors’ moisture content, potentially locating the affected area.
What is the best way to dry out wood?
Wet/Dry Vacuum. If the moisture in your hardwood has come from a leak or accident, such as a turned-over mop bucket or dishwasher overflow, the best way to ensure the wood is as dry as possible is with a wet/dry vacuum. This specialized vacuum is designed for sucking up standing water.
How thick should floorboards be to level a cupped floor?
1. Examine the cross-section of the floor in a doorway to determine its sanding history. New floorboards are usually 3/4 inches thick, and to level a cupped floor, you may have to remove as much as 1/16 inch or more of the wood. Boards that are less than 5/8 inches thick should probably be replaced.
What is the difference between gapping and cupping?
Cupping occurs when the boards swell and push against each other, raising their edges; gapping occurs when they shrink. If the problem is confined to one or two boards, you can replace them, but it's more common for the problem to be widespread on an old floor.
What to wear to prevent dust from getting into the air?
Wear a dust mask and cover the doors and windows with plastic. It's also important to cover air intake vents to prevent the dust from getting sucked into the central air system. Chris Deziel has a bachelor's degree in physics and a master's degree in humanities.
Do you have to replace engineered wood floors?
If your examination of the floor reveals that the boards are engineered with a veneer, then you'll probably have to replace the floor. Sanding engineered boards enough to correct cupping will probably wear off the veneer.
What is hardwood floor cupping?
Hardwood floor is made by putting together planks. Sometimes the balance of moisture inside these planks gets destroyed. This results in the planks swelling on the inside.
What causes hardwood floors to cup?
There are many reasons why hardwood floors start cupping. Some reasons are temporal while others are permanent. Let’s look at some of them:
How to dry out and fix cupping hardwood floors?
Sometimes, the cupped hardwood floors will fix on their own. But most of the time, the cupped hardwood floors need fixing . The drying out and fixing process will be discussed below.
Can it be repaired?
Sometimes the cupping of the hardwood floor can be temporary. In that case, the swelling of the planks will be gone and the hardwood floor will regain its normal structure.
