Are Bathroom Cabinets Waterproof? [And How To Waterproof Them Even More]

Water damage can be a considerable inconvenience to homeowners, often costing hundreds of dollars to repair. One of the most common places where the damage may occur is in the bathroom cabinets. But what's the best way to protect cabinets from water damage? We've researched some of the best methods to waterproof your bathroom cabinets. Please keep reading to learn more about them.

Here are a few methods that you can use to waterproof your bathroom cabinets:

  • Use high-gloss paint
  • Replace the cabinets with laminate
  • Apply caulk to sink area
  • Install a waterproof mat
  • Apply polyurethane
  • Install a leak alarm
  • Apply a varnish
  • Seal all under-sink pipes

It's best to look at waterproofing as a multi-pronged approach to protecting your entire bathroom. This may include using several different methods to waterproof your cabinets. Continue reading to learn common techniques that you can start using today.

Bathroom with cherry cabinet and marble tub. Are Bathroom Cabinets Waterproof [And How To Waterproof Them Even More]

Ways to Waterproof Bathroom Cabinets

Use high-gloss paint

Applying a few coats of high-gloss paint can help to protect your cabinets from water damage. The glossier the paint is, the longer water will take to penetrate the surface of the wood. Paints that are eggshell, satin, and semi-gloss may provide some waterproofing as well. However, they pale in comparison to higher gloss paint sheens. Though high gloss paint is not entirely waterproof, it will have less porosity than other paint sheens.

Bathroom interior with cheerful curtain and wooden cabinets

Check out this high-gloss paint on Amazon.

Replace the cabinets with laminate

If you're especially concerned about your bathroom cabinets becoming water-damaged, consider replacing them with laminate cabinets. These cabinets are made to stand up well to water, meaning that they won't bubble, swell, and become soggy if they become flooded with water. The price for these cabinets will range depending on their size, though they are generally less expensive than hardwood cabinets. You can also find these cabinets available in several different styles, colors, and patterns.

Apply caulk to sink area

When water damage occurs in the bathroom, it often occurs in the sink area instead of the shower. If your sink begins to drip, it can cause a lingering trickle with can eventually eat away at your cabinets. To prevent this, it's best to make sure that the area between your cabinet and the bathroom sink is completely lined with caulk. Silicone caulk works best.

It's expensive and relatively easy to install. And it's also helpful to perform a quick water test once the silicone has tried to ensure that it is completely sealed.

Learn more about silicone caulk on Amazon.

Install a waterproof mat

Another great option to waterproof your bathroom cabinets is to install a waterproof mat at the bottom of the cabinet. These cabinets go beneath the sink and work very effectively to prevent significant damage to the cabinet's interior. If you have leaky pipes or a dripping sink, it can be beneficial to place one of these mats in the cabinet to minimize damage.

The great thing about them is that they can be cut to specific sizes to match the size and shape of your cabinet. This way, you can have wall-to-wall protection on the floor of the cabinet.

Apply polyurethane

Polyurethane is one of the best waterproofing sealants that you can use on your wood cabinets. Whether you purchase a spray-on polyurethane or a liquid version and apply it with a paintbrush, it can provide protection 24/7 against water damage.

Using a high-quality poly sealer on the corners and edges of your cabinet can prevent the water from penetrating the surface of the wood--it's completely waterproof. The sealant combined with a waterproof mat can offer you superb protection against water damage. Polyurethane is fairly inexpensive and can be purchased online or at any local hardware store.

Check out this polyurethane on Amazon.

Install a leak alarm

Installing a leak or flood alarm beneath your sink can help to catch water leaks before they cause significant damage to your cabinet area. These alarms can range from $25 to upwards of $70, depending on its brand and features. If you have a costly cabinet, it's definitely worth it.

These alarms work by using a sensor to detect moisture, and when it reaches a certain level, the alarm will sound anywhere from 90 decibels or more to notify you of the leak. They pretty much work in the same way as fire alarms, but for water instead.

Learn more about this water leak alarm on Amazon.

Apply a varnish

You may hear the terms varnish and polyurethane used interchangeably. And though they are similar in many ways, they are two different products. Varnish contains oil, resins, and solvents and is commonly used in outdoor and indoor wood applications. It cures into a glassy film with a slightly yellow tint.

When you apply it to the wood, it will provide a thin film that is completely waterproof. Varnish is low in toxicity and can be easily applied using a foam roller or paintbrush. You can purchase it from any local hardware store or online, and varnish can be easily applied to most hardwood surfaces. You can also apply varnish to MDF and laminated wood surfaces.

Read more details about this varnish on Amazon.

Seal all under-sink pipes

Applying sealant to the pipes beneath your sink can be crucial to protecting your cabinets from water damage. Keep in mind that these pipes have water flowing through them daily, and if they're old or have been installed improperly, they can be at risk for a leak. Don't underestimate these pipes because of their size, as a single 1/8-inch pipe can leak over 200 gallons of water over time if it's left unnoticed.

If you notice any recurring leaks with your pipes or if they're starting to get particularly noisy, this could be a sign that it may be time to replace them. You can purchase silicone sealant, joint compound, or flex putty to seal the pipes under your sink properly.

Learn more about this pipe sealant on Amazon.

How do I protect my bathroom cabinets from water damage?

The best way to protect your bathroom cabinets from water damage is to use a varied approach for prevention and waterproofing. This includes checking for leaks, installing a water mat or leak arm, sealing the cabinetry and sink area, and applying a cured sealant to the wood itself.

Are vanity units waterproof?

It depends on what the vanity is made of. However, most vanities won't be completely waterproof as many are made of wood, wood composite, or stone, all of which have some porosity. However, if the vanity is sealed, then it can be waterproof. 

How can I waterproof my bathroom wood?

You can waterproof your bathroom wood using a sealant that is specifically made for wood. These ceilings and food polyurethane or varnish. What makes the ceiling so effective is that they are made of resin and other materials that will cure, leaving the woods with a light waterproof coping towering making them penetrable to moisture.

These sealants are relatively easy to apply and can be purchased and most hardware stores or online. It is essential to ensure that you are using a clear sealant unless you plan to change the color of the wood. While polyurethane typically goes on clear, varnish can leave a yellow or amber-colored tint to the wood.

What is the best material for a bathroom cabinet?

Yellow bright small bathroom with wooden cabinets

Most bathroom cabinets are made of wood. But what type of wood is best? Let's take a look at the most popular ones.


If you would rather not shell out the extra dollars for teak, consider Birch. Birch is a popular vanity hardwood as it is easy on the eyes and has properties similar to that of maple. It has a natural closed-grain structure naturally waterproof and is also fungus and rot-resistant, making it perfect for moisture-prone areas such as bathrooms.


Maple is another top choice for cabinetry due to its even grain and beautiful smooth finish. It's very easy to paint, is readily available, and is a relatively affordable option compared to other inexpensive wood such as cherry or walnut.


Teak wood is another great choice for bathroom cabinetry as it is incredibly durable and produces natural oils that are water-resistant. While teak may be more expensive than other hardwood options, it may be worth it if you're looking for a hardwood that is both durable and stands up well to water.

Wrapping things Up

Making sure that your bathroom cabinets are waterproof can potentially save you hundreds of dollars in repair damage. Taking preventative measures to protect them can help minimize any damage if the pipes or sink began to leak.

Before you go, be sure to check out our other posts:

Should You Have Ceiling Fan In Your Bedroom?

Nail Pops In Drywall Ceiling Or Walls – What To Do?

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