what happens to wood when it gets wet
Kristina Davis

What happens to wood when it gets wet? I’ve certainly experienced some wet wood disasters over the years.

However, in almost every case, I could have prevented long-term damage if I had known what was happening.

A little bit of prevention could have saved me from ruined furniture surfaces, warped wooden floors, and even costly termite damage.

It turns out that some wood is more porous than others or more rot resistant. 

Plus, there are plenty of ways to keep wood dry to prevent damage. You just have to be diligent and notice the environment around wood before the damage happens.

We’ll explore how the wood absorbs water and how to prevent wood damage.

Then, we’ll dive into the types of damage that can happen if you don’t protect your wood from wetness. 

Wet wood damage includes warping, splitting, discoloration, mold, rot, and attracting pests.

How Wood Absorbs Water

how absorbs water

While a tree is alive, it has bark, waxy coatings, or resin that keeps water out when it rains.

Wood you use in your home has been cut, sanded, processed, and doesn’t have the same protection from water as a tree does. Thus, it absorbs water instead of repelling it.

So, while a tree can endure decades or even centuries of rain and moisture, cut wood cannot.

Did you know that wood cells absorb water both in their liquid form and as water vapor in the air?

As a result, you have to think about protecting wood from spills, wet environments, and humid environments. 

The Porosity of Different Woods 

porosity of wood

Different types of wood have different pore sizes, which affects how well they absorb liquids.

If you spill water on wood with bigger pores, the wood is more likely to absorb water or other liquids. On the other hand, non-porous woods won’t absorb as much water.

So, if you’re picking out furniture for a damp room or if you’re a clumsy water spiller like me, the type of wood you choose may matter.

Open-Grain Woods

Open-grain woods have the biggest pores and absorb liquid the easiest.

Thus, you may want to steer clear of open-grain woods for wet environments and places you expect spills and dampness. 

Open-grain woods include:

  • Oak
  • Ash
  • Hickory
  • Maple

Close-Grained Wood

closed grains

Close-grained woods don’t absorb water and moisture as easily as open-grain woods.

So, they’re less likely to become damaged from a water spill or moist environment.

Choose close-grained woods for outdoor projects or for furniture that is more spill-resistant.

I’ve often marveled that Japanese bathrooms contain so much wood that stays in good shape.

It turns out that their secret is that they use close-grained woods like hinoki cypress.

Close-grained woods include:

  • Pine
  • Cherry
  • Walnut
  • Cypress
  • Cedar

Preventing Water Damage to Wood

preventing water damage

What happens when wood furniture gets wet? Since wood is porous, it can become oversaturated and damaged by water.

Since you know that wood absorbs water, you have to do what you can to keep water and moisture at bay.

Keeping Wood Dry

The most obvious way to protect the wood from moisture damage is to keep wood dry.

If you have a wooden floor, you’ll want to wipe up spills immediately.

Placing rugs in areas that are more likely to become wet can help.

I have one in front of my refrigerator because my ice maker likes to throw ice all over the wooden floor. If you spill something onto wood, pat it dry immediately.

Tip: Move wet furniture to a well-ventilated area, and apply baking soda to draw out any remaining moisture.

Checking Regularly for Damage

check regularly

Inspect wooden furniture, floors, and fixtures regularly for damage.

If you notice a problem early, you have a bigger chance of being able to fix it or prevent further damage.

Monitor Humidity Levels

Another way to protect wood is to monitor humidity levels. Humidity is the measure of how much moisture is in the air.

You can use a dehumidifier in rooms like bathrooms that stay damp. Fans and open windows can also help water in humid areas evaporate.

Water Sealants and Waxes

water sealant

A water sealant or wax provides wood with protection from water absorption.

Consider using a sealant or wax to create a barrier from water in moist environments.

After all, a living tree trunk produces waxes and resins to protect itself from rain.

Sealants tend to last longer than waxes. However, you will need to reapply both eventually to continue to provide water protection.

What Happens to Wood When It Gets Wet?

So, What happens to wood when it gets wet?

When wood absorbs water, it can warp, swell, crack, rot, discolor, grow mold, or collect pests.

Warping

warping of wood

Warping happens when the moisture level in a piece of wood changes unevenly. One area dries and shrinks faster than others, causing warping.

Tip: It may be possible to apply moisture and heat to the other side of the wood to unwarp wood.

Splitting and Cracking

If your wood gets wet and then shrinks as it dries, it may split and crack.

Unfortunately, once the wood has split and cracked, there’s not anything you can do to repair it beyond filling in the cracks.

Tip: A sealant, varnish, or wax can help prevent cracking.

Discoloration

We’ve all experienced putting a glass of liquid down on a wooden surface and lifting it to uncover a ring.

Discoloration of a wood’s surface may be temporary until the water evaporates.

the discolorations

However, there’s always the chance it could be permanent, especially on stained wood.

Tip: Merrymaids suggest removing water discoloration by placing a dry cloth over the wet area and ironing the area in 30-second increments.

Mold

Wet wood is also a breeding ground for mold. Fungi love damp environments, so if mold or mildew spores have made their way to your wet wood, they’re going to thrive.

You’re most likely to see mold in the bathroom, but it could occur elsewhere, too.

According to the Environmental Protection Agency (EPA), it’s impossible to get rid of all mold spores indoors.

Therefore, prevention and control are key. Reducing condensation and keeping indoor humidity below 60% is also vital to prevent mold.

Tip: If you clean up a wet area within 24-48 hours after a spill, mold shouldn’t grow even if there are mold spores present.

Rot

The type of fungi that causes wood to rot is saprophytic, which means that it eats decayed material.

Decay fungi need water to survive and are active at 77°F to 90°F.

So, if their spores are present in your wood when it’s wet and warm, they’re going to chow down.

wood rot

Luckily, there are several rot-resistant woods that you can choose if you want to add wooden furniture to a warm and damp area:

  • Teak
  • Rosewood
  • Oak
  • Redwood
  • Cedar
Tip: Using dehumidifiers and fans can help prevent wood rot in damp areas.

Pests

There are plenty of pests that like to dine on wood, especially when it becomes damp and soft from rot.

Unfortunately, they can invade furniture as well as walls. And, once they’ve set up house in your house, your wood will only deteriorate more. 

Termites are the most well-known insect that enjoys rotten wood.

wood pests

According to Orkin, if they make their home in your home, you can expect to spend an average of $3000 to repair the damage.

Carpenter ants and bees also seek out rotten wood.

Because they love decaying and moist wood, you’re even more likely to find them in damp areas of your home like in the bathroom or around your sink or dishwasher.

Final Thoughts on Wood Getting Wet

What happens when wood gets wet? Wet wood is prone to warping, splitting, discoloration, mold, rot, and pests.

Sometimes, these disasters occur in dark, damp areas while we’re not watching.

However, sometimes we can do something to prevent these problems by being more vigilant.

Keeping wood dry and humidity low is key to keeping wood in good shape.

Additionally, choosing close-grained and rot-resistant wood can keep your wooden furniture, floors, and fixtures looking nice for years to come.