Understanding how to waterproof your bathroom cabinets helps maintain their longevity and ensure they remain free from damage caused by moisture, dampness, and mold.
Bathrooms are naturally humid environments, depending on your bathroom’s ventilation and humidity levels, moisture can wreak havoc on materials like wood.
Wood cabinets, in particular, are susceptible to swelling, rot, and mold if they are not properly treated to be waterproof. Here are some steps that you can follow to protect your bathroom cabinets from moisture damage and ensure they last for years to come.
What Are Most Bathroom Cabinets Made From?
Most bathroom cabinets are constructed with a laminate finish that is both waterproof and durable. Laminate surfaces are nonporous, allowing moisture to be wiped off easily without absorbing the material.
On the other hand, wood is porous, which means it can absorb moisture if not adequately treated. When exposed to high humidity or direct water, wood can swell, rot, or even develop mold over time. Therefore, it is essential to ensure that any wood surfaces in your bathroom are properly sealed and waterproofed to avoid potential damage.
Damp, Mold, and Moisture
Moist bathroom surfaces create the perfect environment for mold spores to thrive. Black mold, in particular, is notoriously difficult to remove once it takes hold and poses significant health risks. This makes it imperative to waterproof not just your cabinets, but also other bathroom surfaces that are prone to moisture exposure.
Steamy showers and baths increase humidity in your bathroom, which is often a smaller, enclosed space. This can lead to condensation forming on surfaces. To check if your cabinets are already suffering from moisture damage, ask yourself the following questions:
- Do the drawers in your cabinets open smoothly?
- Do the doors close easily?
Before you begin sealing and waterproofing your wooden bathroom cabinets, it’s crucial to check if they have already been damaged by water. At the same time, you should evaluate whether your current cabinets offer enough storage to meet your needs. There are many strategies to optimize storage space in your bathroom.
How to Waterproof Your Bathroom Cabinets
There are a few expert methods, you can use to protect your wood cabinets and shelving from moisture. Creating a waterproof seal is essential, but the method you choose should depend on the type of wood grain in your cabinets. Some effective methods include:
- Hand-rubbing with linseed or tung oil
- Sealing with polyurethane, varnish, or lacquer
- Using a stain-sealant combination
Each of these methods provides an extra layer of moisture protection, helping to extend the life of your bathroom cabinets.
Similar: How to Waterproof Bathroom Vanity Cabinet
Tools and Materials
Keep in mind that bathrooms are typically smaller, enclosed spaces, so any paints, varnishes, or sealants you apply will release chemicals into the air. Make sure to open any available windows and carefully read the caution warnings on the products you use.
If possible, you may want to remove your bathroom cabinets entirely and work in a larger, better-ventilated space. Here are the tools and materials you will need:
- Linseed oil, mineral spirits, and polyurethane (if you plan to make your oil mixture)
- Natural bristle paintbrush
- Rags
- Fine-grit sandpaper
- Polyurethane sealant, wood varnish, lacquer, or wood stain
Oil Rub Finish
This method is especially suitable for dark-grained woods like walnut and mahogany.
Mixing oils with mineral spirits and polyurethane reduces stickiness and helps the finish dry faster.
This traditional method has been used for centuries to waterproof wood.
However, if your bathroom cabinets are made from lighter-colored woods like pine or ash, avoid hand-rubbed oils as they can cause the wood to yellow over time. You can either purchase pre-blended oils or make your own by combining one part linseed or tung oil, one part mineral spirits, and one part polyurethane.
Caution: Oil Rags Can Spontaneously Ignite
As oil dries on a rag, it generates heat, which can cause the rag to ignite even if it’s not near a flame. To minimize the risk of fire, follow these safety tips:
- Keep a bucket of water nearby.
- When a rag becomes saturated with oil, drop it in the water and use a new one.
- Hang rags separately to dry.
- Discard and never reuse old oil-soaked rags.
Using Sealants
Sealants are relatively simple to apply and provide excellent waterproofing protection for your cabinets. You can either brush or spray on polyurethane, varnish, or lacquer after thoroughly cleaning and sanding the wood.
We used sealant to waterproof our cabinet, and you can use it to make your bathroom cabinet waterproof as well.
Sealants are very useful for filling tile gaps in walls, toilet and floor joints, doors, cabinets and many furniture items.
Keep in mind that when applying sealant to your bathroom cabinet, after the first coat dries, you’ll need to lightly sand the surface again before applying additional coats.
What is the Difference Between Sealants?
Each type of sealant offers unique properties:
- Lacquer creates a hard, scratch-resistant finish.
- Polyurethane sealants contain acrylic and polyurethane resins, and they are available in finishes ranging from high-gloss to soft sheen.
- Varnish is composed of resin, solvent, and drying oil, offering both waterproof and scratch-resistant protection. Polyurethane varnish is the best option for waterproofing wood surfaces in your bathroom.
Pro Tips
To achieve the best results, apply sealants and varnishes at room temperature. While many sealants dry quickly (some within 15 minutes), it’s essential to be cautious when working with sticky varnishes or paints. Here are a few tips to keep in mind:
- Work on one side of the cabinet at a time.
- Ensure the sides are dry or place the cabinets in a safe, designated area to dry.
- Avoid stirring the sealant or varnish, as this can create bubbles that will remain even when the product is dry.
When setting up your workspace, make sure to take safety precautions by using fans for extra ventilation. Waterproofing your bathroom cabinets is a key step in maintaining the wood’s integrity and ensuring that your bathroom stays functional and beautiful.
If you’re looking for a pre-made bathroom cabinet, The best options are below
Conclusion
Waterproofing your bathroom cabinets is not just an aesthetic improvement, but also a necessary step in protecting your investment from moisture-related damage. By selecting the right waterproofing method, using high-quality sealants or oil finishes, and maintaining proper ventilation in your bathroom, you can extend the life of your cabinets and prevent mold, rot, and other moisture-induced issues. With the right tools and techniques, your bathroom cabinets will remain in excellent condition for years, even in the face of constant humidity and water exposure. Proper waterproofing will keep your bathroom stylish, functional, and free from damage.