How to Make Wood Waterproof for the Bathroom

Wood is a natural material that becomes mildewed or odorous when exposed to water. Although it resists most liquids, there are certain ways you can protect your wood against moisture damage. The following information will help highlight some techniques for making wood waterproof for the bathroom.

Keeing these things in mind, we came up with different ideas on how to make wood waterproof for the bathroom.

What Constitutes a Moisture Problem?

Many wood species will develop a white, powdery substance on the surface when they are exposed to excess moisture or humidity. This is not a moisture problem per se, but it indicates that the wood has been affected by water somehow. Excess moisture can cause warping, cupping, and splitting in dry woods like cedar and redwood. But even in an area with low humidity, these woods may warp slightly during extended periods of rain or snow. It is best to avoid using these types of wood in areas where they will be exposed to moisture. For most other types of dry hardwoods, you can wipe up any liquid spills with clean water rather than allowing them to soak into the wood.

You should also be aware that some woods can absorb more water than others. For example, redwood is highly absorbent compared to other types of wood. Because these materials are softer than cedar or redwood, you must take extra care not to let the wood stay wet for an extended period.

Some woods like solid maple or cherry are fairly resistant to water damage, but they will stain if you allow any liquid to stand on them for long periods. Keep in mind that these stains may not be removable after they have had a chance to set into the wood surface. There is no way to make your bathroom floor waterproof other than sealing it with multiple coats of polyurethane varnish, which will affect the color and luster of your flooring. The best method for making wooden floors moisture-resistant is applying a light coating of wax or polyurethane finish.

5 Methods – How to Make Wood Waterproof for the Bathroom

how to make wood waterproof for the bathroom

1. Using Oil to Protect the Wood

The easiest way to make wooden bathroom floors, cabinets, and woodwork waterproof for the bathroom is by applying a protective coat of oil.

First, clean the surface with naphtha or turpentine. Allow enough time for the residue from these solvents to evaporate before completely applying a coat of oil.

Next, mix a small amount of boiled linseed oil with equal mineral spirits (paint thinner).

Apply this mixture onto the dry surface using natural bristle brushes or synthetic ones (the type used for exterior painting jobs). You can also apply this oil mixture with rags or lint-free cloths.

Allow it to stand overnight before wiping off any excess material using clean water.

Repeat these steps until you have applied three coats of the oil mixture to your wood surface.

You can then use a lightweight paste wax or oil finish on top of the dried, slippery surface for added protection against water damage.

2. Making Wooden Floors Waterproof Using Polyurethane Varnish

You can waterproof wooden floors using polyurethane varnish in much the same way that you would apply any other type of flooring material. Because these surfaces need to be completely smooth and level, it is best if they are either prefinished (using an adhesive) or oriented strand board (OSB).

First, cover all electrical outlets and switches with masking tape and paper to prevent them from getting stuck with the varnish.

Use 8-ft.-long 2″ x 6″ planks to create a temporary wall around the base of your work area to contain any splashes or drips. Ideally, you should use an airless sprayer (purchased at hardware stores) to coat the surface evenly; however, you can also apply this material with brushes or natural bristle rollers. These rollers are not ideal because they may leave streaks if not used correctly.

When applying polyurethane, begin in one corner and move steadily towards another while slightly overlapping each pass. Ensure that you allow enough time for drying between these coats; otherwise, jagged lines will form on your floor from the repeated passes of your brush or roller.

To ensure you get a smooth, even coating of varnish, allow a drying time of at least 24 hours before applying more coats. Usually, three coats are enough to protect wood surfaces against water damage; however, you can add a fourth one if necessary for added protection against scratches and moisture absorption.

3. Applying Wax

One method for protecting wood surfaces against water damage is by using wax. These products are available in either paste form, which you should apply with a natural bristle brush, or liquid form, which you can spray onto your work area either manually or via an airless sprayer. The latter option will ensure the evenest coat of product onto your surface while also saving time and effort compared to applying coating material with a brush.

Both types of finish must be applied to dry surfaces only completely! Allow adequate drying times before walking on them as well as before adding more coats. Two coats should be enough to protect wooden floors against water damage, but if you want the best protection possible, it is recommended that you add a third coat.

4. Using Water Repellent Wood Stain and Protector

Another option for protecting wood surfaces against water damage is to use a water-repellent wood stain and protector product. These materials give your flooring surface an even color while providing excellent protection against water damage. This treatment also features low-maintenance requirements; however, it will wear off over time (usually within 12 to 18 months).

The first step of this process is simple: Thoroughly clean the area around which you will apply these materials using terry rags or lint-free cloths that have been dipped into mineral spirits (paint thinner) then wrung out completely. You can then apply the material by wiping it onto the surfaces or spraying it evenly using an airless sprayer.

It is important to note that the color of these materials will not be even after you have applied them. Instead, they will look blotchy, with lighter and darker areas throughout their surface.

Fortunately, these inconsistencies are usually corrected after several days when this material dries completely. Eventually, your flooring surface should become glossy, which indicates that its protective properties are finally active.

Some water-repellent wood stain and protector products need to be reapplied every six months to maintain top-quality protection against water damage; however, most brands offer a self-polishing finish that eliminates this step for at least 12 months of excellent protection against water damage.

5. Using Penetrating Oils and Waxes

Last but not least, the use of penetrating oils and wax will protect wood surfaces against water damage.

To apply these materials, you should first clean your flooring surface using terry rags or lint-free cloths that have been dipped into mineral spirits (paint thinner) then wrung out completely.

Afterward, you should wipe away any residue using a rag dampened with turpentine.

Then you can start applying one of the following materials: Raw linseed oil, tung oil, boiled linseed oil, or carnauba wax. Each material has its specific application method; however, it is recommended that you read the instructions on each container before starting this process to ensure success.


Wood surfaces are vulnerable to the water damage caused by exposure to liquids which cause swelling, staining, and warping as water is absorbed into its grain. Moisture also tends to attract mold and bugs that infest wood fibers. Fortunately, applying the right protective measures before any damage occurs will make it much easier for you to protect your hardwood floors from going under.

Thank you for reading. Have a nice day.

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