Cupping is a wood floor’s natural reaction to moisture. … When water seeps into a plank of wood flooring, the side of the board closest to the moisture will expand. Cupping occurs when the edges of the board are higher than the center of the board, creating a concave shape.

How is cupping in wood caused?

As we’ve learned, wood floor cupping is caused by the expansion of the floor planks due to moisture.

Why are my wood 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.

Will hardwood cupping go away?

This cupping will gradually subside with time and multiple seasonal changes but may not completely go away. The most often repair choice is to re-sand and refinish the flooring. … Sanding a floor that is cupped 3/64” or greater will likely remove more than 1/16” of the wear surface.

Why is my hardwood floor curling?

Curling is one of the worst defects a hardwood floor can sustain, and you can’t always fix it. Unless there has been flooding, it’s usually caused by moisture seeping through the subfloor or by conditions of extreme humidity in the immediate environment. The planks swell when they get wet and push against one another.

Can cupped wood floors 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.

How do I stop cupping from shiplap?

Kerf to prevent cupping. You can reduce the chance that a board will cup by creating relief kerfs on the backside. Set a table saw or circular saw to a depth of about 1/8 in. and make two cuts lengthwise along the back of each board.

What do you do with cupped wood floors?

Fixing a Cupped Floor 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.

How do you reverse cupping on hardwood floors?

You can also turn up the air conditioner or keep the fans on to speed up the drying process. Dehumidifiers remove moisture content in the air and if you are lucky, a simple dehumidifying session might do the trick and help reverse the hardwood floor cupping.

How do you get moisture out of hardwood floors?

While the wood flooring appears dry, water could have penetrated throughout the plank as you can’t remove it with the wet vacuum. 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.

Article first time published on

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 a dehumidifier help wood floors?

A Dehumidifier Is Actually a Bad Idea for Hardwood Floors Or you notice some of the floorboards have started to bend and the edges may curve up or down. Cracks may have appeared in the floorboards. … It’s not a dehumidifier you need for your hardwood floors, but a whole-home humidifier.

Can you plane a cupped board?

In order to flatten a warped, twisted, or cupped board, a common approach is to first use a jointer to create one perfectly flat face. Then you run the board through a thickness planer with the flat face downward, and the planer makes the top face parallel to the bottom.

Can you Unbow wood?

Heat is one of the most common methods used to unwarp wood. There can be different types of wood deformation including twisted, cup, bow, etc. It is always not possible to unwarp the wood into its original shape. But you can get close to fix the problem, only when you know how to use heat properly.

Can a planer fix cupping?

It is difficult to flatten a cupped board with a thickness planer because the downward pressure of the feed rolls will press out much of the cup, thereby not allowing the planer knives to flatten the board. As it emerges from the planer, it simply springs back to its original cup.

How do you keep a table top from cupping?

A straight cleat, screwed to the underside of a drop-leaf table, an extension table, or a pedestal table, is a simple and effective way to keep a top flat. don’t use glue here, however, or the top won’t be free to expand and contract with changes in humidity, and that could cause the top to crack.

How do you make shiplap moisture resistant?

You can also apply a clear coat sealer to the boards to give them an additional layer of moisture protection. This is not necessary if you are using our prepainted shiplap boards, but we do recommend applying wood sealant on any exposed edges or seams to ensure moisture resistance.

What causes shiplap to warp?

Boards can be exposed to rain, humidity and other climate factors that affect the total moisture content of the boards. This unbalanced exposure can cause the once flat boards to deteriorate in the form of: Bowing: warping along the length of the face of the wood.

How do you keep plywood from cupping?

The best way to store plywood, to prevent it from warping in the first place, is to lay it flat. Rather than laying it directly on the floor of your workshop, use pieces of lumber to create a platform, albeit a makeshift one, for the plywood to sit on.

What is the bark side of a board?

“Bark side down” orients the board so the end grain growth rings curve upward. This creates a crowning warp when wet. As a result, water is shed from the board, as opposed to pooling on it. Also, the exposed board face is heartwood (closer to the tree’s center) versus sapwood, and heartwood is more decay-resistant.

What is deck cupping?

The Cause of Deck board Cupping is uneven moisture content from one side of the deck board to the other. If while looking at the end view of a decking board, the board is bent into a slight “U” shape, you are observing “cupping”.

Why is my floor bulging?

When a floor board starts to bulge, it’s usually because it is warped. Hardwood floors usually warp because they have been exposed to water, or excessive humidity. The water causes the fibers in the wood to swell and shrink. A board that is severely bulged will most likely need to be replaced.

What causes floors to buckle?

Buckling. Floor buckling is the most extreme reaction to moisture in a hardwood floor. Buckling occurs when the wood flooring actually pulls up from the subfloor, lifting several inches in one or more places. … Floor buckling happens most often after a floor has been flooded for an extended period of time.

Does baking soda absorb moisture from wood?

Liberally sprinkle baking soda inside the furniture to help absorb the moisture from the wood. … Use a fan to blow air over the piece, or place furniture in a bathroom with a dehumidifier.

Is it okay to mop hardwood floors?

A regular once-over with a broom or dust mop will do wonders for cleaning hardwood floors. … For a quick clean, dust wood floors with a mop that has been treated with a dusting agent to pick up dust, dirt, and pet hair that might scratch the floor surface.

Will a dehumidifier remove water from floor?

Dehumidifiers work by removing moisture from the air and replacing it with dry air. Used in conjunction with fans and heaters they can speed up drying out a floor. The problem with using a dehumidifier to dry out a floor is that it will collect moisture from the entire room not just the wet surface.

Why are my floorboards moving?

More often than not, the reason for the moving and shifting of your laminate floorboards is because it may not have been installed properly. … In many other cases, the moisture content present in the wood is also one of the major reasons behind the moving and shifting of the laminate floorboards.

How do you fix a hump on the floor?

1. Cut the subfloor. Use a circular saw to remove the subfloor to expose the high joist.
2. Look at the joist. The joist underneath the hump may appear thicker than the joist on either side of it because of moisture.
3. Shave down the higher joist. …
4. Install the subfloor. …
5. Mount the new floor over the subfloor.

Why does my wood floor buckle in the summer?

During the summer, all wood floors tend to expand because wood reacts to moisture. Air with a high moisture content (MC) or high relative humidity (RH) causes wood to gain moisture. Extreme moisture can cause cupping (when the edges raise higher than the middle of the wood planks) or even buckling.