The best way to care for your bamboo shower bench is to let it dry out completely after use. If water pools on the surface of your bench when you shower, use a squeegee or other tool to fully take the water off. Once it's dry, mix a solution of vinegar and water and wipe it clean once a week. This should prevent any mold or mildew from building up on the surface.
Do not use bleach on your bamboo bench, though. This could lead to it drying out prematurely and cracking. The cracks will allow the infiltration of water into the bench's interior, which makes it more prone to molding.
Though bamboo shower in the case of bamboo be naturally water-resistant, there may come a time you need more. As water and weather affect your bench, it may start to show signs of age and wear. You can give it a little help with waterproofing.
Once your bench is totally dry, give it a light sanding. Then, using a durable matte finish polyurethane, give it one coat of finish. This should help protect your bench against any further wear.
Any wooden shower benches can get moldy over time, though. You can help prevent this by squeegeeing the bench after each shower and removing any standing water. Another helpful tip is to keep your shower fan running until the moisture post-shower is dried up. Bleach won't kill mold that's infiltrated the surface. The best advice is to dry out the bench entirely, then use a commercial product to get rid of the mold.
