GBA Logo horizontal Facebook LinkedIn Email Pinterest Twitter Instagram YouTube Icon Navigation Search Icon Main Search Icon Video Play Icon Plus Icon Minus Icon Picture icon Hamburger Icon Close Icon Sorted

Community and Q&A

Wood floor in bathroom

user-5378275 | Posted in General Questions on

I’m installing a new rift and quarter sawn white oak 3″ floor in my new home and I’m going to use wood for bathroom floor as well. i was planing on using same flooring in bath with no seams and pre seal t&g,bottom and end grain before install and a couple extra coats on top. an option would be to use maranti mahogany instead but i would rather stick with the oak. any thoughts? thanks.

GBA Prime

Join the leading community of building science experts

Become a GBA Prime member and get instant access to the latest developments in green building, research, and reports from the field.


  1. GBA Editor
    Martin Holladay | | #1

    You can install oak in your bathroom if you want. I've installed hardwood in bathrooms before. After 20 years, you might regret it.

    In my own home, I installed a cherry floor in my bathroom. After 15 years or so, I replaced it with tile, when I began to see signs of flooring rot near the toilet and at the edge of the bathtub, where my kids let the water slosh over.

  2. charlie_sullivan | | #2

    Wood expands and contracts with humidity, and standard wood floors can be expected to have fine cracks between the boards when humidity is low. Narrow boards make these cracks small, and it works fine for most rooms. But I don't know of a way to prevent water from getting in those cracks in a room where water sloshes on the floor. So I think Martin's experience is not surprising.

    Just for fun, here a brainstorm about a way to avoid the problem. I make no claims that this is practical--I hope people enjoy pointing out why it is not.

    Build the wood floor like a tabletop, with the boards glued together tightly, but not anchored to the sub-floor, so that the whole thing can expand and contract together. Put cleats on the bottom, anchored in a way they can slide, like on a tabletop, to keep it from bowing. Recess the cleats into the sub-floor. One of the problems with this design is that there will be more movement at the edges than you'd expect in a standard wood floor, so that will provide good opportunities for water to get in there. I suppose you could then mount the baseboards to the floor and not to the wall, and then put a Z flashing over the top of the baseboards to hie the crack and prevent water getting behind them. How would brass Z flashing go with your decor?

  3. user-5378275 | | #3

    thanks guys, love you're idea charlie but i'm not going to spend the time. i think i might fab a copper pan with1/2" lip to go under toilet and 1/2" x 1/2" track at tub to catch water. poly caulk track to tub and floor, and hope seal don't break during expansion contraction......????

  4. STEPHEN SHEEHY | | #4

    Maybe tile under toilet and along tub edge, with the oak everywhere else.

  5. user-5378275 | | #5

    thanks stephen, but then you still have seams that can leak if caulk fails. pan under toilet would be on top of flooring, simple and effective with caulk under perimeter to stop floor moisture from getting in between. and track at tub also on top of flooring with poly back caulk first tub to flooring then track caulked to tub and flooring under track, i think it will be quick and effective and hopefully look ok. ?????

  6. user-5378275 | | #6

    the wife is saying no track and no pan, so back to the drawing board, does anybody know which moves more, rift and quartered white oak or maranti mahogany?

  7. charlie_sullivan | | #7

    I don't know for sure about oak vs. maranti mahogany, but I do know for sure that rift/quartersawn will help so I'd go with that.

  8. user-5378275 | | #8

    right, and white oak doesn't blacken, used on boats and such.

  9. STEPHEN SHEEHY | | #9

    Ben- I was thinking of a single piece of stone under the toilet, maybe a scrap from a countertop fabricator, set in the same plane as the oak floor. If you go with just oak, run hot water to the toilet to temper the water temp and avoid sweating.

    We put in a prefinished bamboo floor in the bathroom in our old house, including under the toilet, and after ten years had no problems at all.

    Is it too late to install a wall-hung toilet?

Log in or create an account to post an answer.


Recent Questions and Replies

  • |
  • |
  • |
  • |