How to Repair Water Damaged Bathroom Vanity

Look closely at the vanity to inspect how damaged it is. Check for signs of water damage. For example, swollen wood, peeling veneer, mold or mildew. Make sure the structural elements are intact and not extremely damaged. 

Before repairing, the vanity needs to be completely dry. Leave it in a dry place for at least 24 hours. You can also set up a humidifier or fans to speed up the drying process.

If your vanity is made of solid wood, use sandpaper with medium grit. Keep sanding and any swollen or damaged wood until you can see the solid and undamaged wood. Then, switch to fine-grit sandpaper to smooth the surface. 

On the other hand, for composite or veneer surfaces, gently sand only if necessary. Try not to damage the veneer or surface layer.

If you are treating mold or mildew in solid wood, mix 1 part bleach with 3 parts water and clean it. For composite surfaces, bleach can be too harsh. Instead, mix 1 tablespoon of mild detergent with 4 cups of warm water ​to clean mold and mildew. It will help clean the area without damaging the surface. Make sure the area is well-ventilated when using bleach. Then, let the vanity dry completely. 

If there are holes or gaps in your vanity, fill them. For wooden vanity, you can use a wood filler or epoxy wood repair compound. And, for composite material, you can use epoxy putty. Spread it with a putty knife. Make sure it is smooth and on the same level as the surrounding area. Then, allow it to dry for 15 to 25 minutes.

Once the wood filler has dried up, sand the filled areas with fine-grit sandpaper. It will give a smooth and even surface. Get rid of all traces of dust with a damp cloth. But, for composite surfaces, avoid sanding if the surface is intact.

​Peel away any damaged veneer or laminate with a putty knife or flat scraper. Cut a new piece after measuring it to replace the surface. Use contact cement for both the new veneer/laminate and the substrate. Carefully set and press it firmly in place. Use clamps to hold it until it sets well.

Apply a mold-resistant primer that is marked suitable for bathrooms. Match the color to the existing vanity finish and apply a coat of paint or stain. Apply at least two coats of stain or paint for a smooth finish. Let each coat dry completely before applying the next. For composite surfaces, consider using a veneer repair kit or touch-up paint to match the existing finish. 

Carefully place the sink and countertop back into the base of your vanity. Position it against the wall and secure it with screws. Make sure it is attached properly. Reconnect the water supply line to the sink and turn the water valves on again. Double check for water leakage.