A. The short answer is yes. When cedar is used in a sauna or closet, it is usually left unsealed and the natural fragrance is released over time. The problem with leaving it unsealed in a bathroom is water. Getting the cedar wet will not hurt it, but it will cause discoloration. Cedar is a very soft wood and will absorb water quite readily. It also has a lot of tannin and that is where you get the discoloration. When water is splashed onto the cedar, it will tend to dissolve the tannin and when it dries, the color will be concentrated in a way that makes the wood look splotchy.

I would recommend sealing it with an oil sealer. It should be applied in a flowing coat, and allowed to soak in. If you are installing the cedar with the rough surface exposed, you can just apply the sealer and let it soak in. If you are installing with the smooth surface exposed, you should wipe off any excess that doesn’t soak in so that you have a uniform appearance. If you have some extra cedar, try out the sealer on that before you apply it to the whole installation to be certain that it will give you the look you want.