Replace Tub with Walk In Shower

This tub is being replaced with a walk-in shower. What’s the best thing to do about the stained-glass window? Photo Credit: Robin Pattison

DEAR TIM: We are about to remodel our master bath and have a round stained glass window over the current tub. We want to remove the tub and have a large shower put in it's place. I would love to keep the stained glass but, as it is not energy efficient, would like to have an insulated window put in it's place. At your website, I read your past article regarding placing a stained glass panel in front of an existing window. I was not sure if this could be done in a shower or if the stained-glass window can be removed without damage. What are your thoughts on this issue? What other tips do you have about this big project? Robin P., Carrolton, TX

DEAR ROBIN: I’m about to embark on my own bathroom remodel project, but I don’t have to solve a window problem like you do. My challenge is to fix all the wasted space in my basement bathroom that was caused by poor planning on the part of the homeowner and architect that built the home I live in. In my case, I’m taping a huge video series about my project and intend to put all of the videos up on my AsktheBuilder YouTube channel so folks like you don’t ever make mistakes in your bathroom projects.

The photo (see above) you sent of your current bathroom with the stained-glass window over the tub is stunning! This window is going to provide you with more than one challenge and you’ve got lots to think about before making your final decision.

Over the years, I remodeled many a home that had a window in a tub / shower area. I can tell you that I discovered problems in all of the houses that were wood framed. Leaks and condensation wreaked havoc inside the walls around and below the windows. The only houses that were immune to damage were ones that were solid masonry and it didn’t matter if water splashed onto the window and / or condensation dripped down the window seeping into the wall cavity.

I can tell you what I’d do just for starters and I want you to chew on this idea. There are any number of tile manufacturers that can take a high-resolution photo of anything and put that image on any number of ceramic tiles much like you see how jigsaw puzzles are made. Doing this you could create the illusion of that gorgeous stained glass window inside your new shower, but it wouldn’t be a real window.

You have so much natural light coming in from your overhead skylight that’s immediately adjacent to the shower area, that it may fool some into thinking the image on the tile is real!

If you were bound and determined to keep the window in your new shower, you’re going to need an expert involved in the project who can create a special leak-proof flashing that will conform to the circular opening you have. The entire wall will need to have a flashing, or high-performance vapor barrier that collects and diverts any water back to the shower base where the water would eventually get to the plumbing drain.

Don’t underestimate the complexity of all of this working together. If you make one mistake with one part, you’ll have a leak down the road. It will be very expensive to fix the problem especially if the defect creates a latent defect where the damage doesn’t show up for years.

No matter what you decide to do, here are a few tips to help you have a shower that will not leak. First and foremost, understand you need to control both liquid water and water vapor. This means you must not allow water vapor into your wall cavity on the exterior wall. Cross-laminated vapor barriers offer, in my opinion, the best protection.

If you have a wood subfloor under your current tub, then consider cleaning it well after the demolition and coating it with two or three coats of clear urethane. Do the same with the wall studs. This may seem crazy, but anything you can do to slow or stop water from soaking into the wood in case of a leak will help prevent rot.

Before coating the wood with urethane, I’d spray on two coats of a borate solution and allow that to dry. Borates are great products to prevent wood rot, but they’re water soluble. The urethane will lock in the borate into the wood for many years.

Think about water that might get behind the finished wall of your new shower. What can be done to FORCE that water into the shower pan so it ends up in the shower drain? Make your contractor do that. Do not listen to his reply that caulk will stop these pesky leaks. You want a permanent solution that’s hidden behind the walls.

Do whatever you have to do to install a traditional access panel on the other side of the wall where your new shower faucet will be. You want to be able to have full access to your shower valve in the future. Don’t allow the contractor to talk you out of this. Access panels to tub and shower plumbing were standard equipment in just about every old house I ever worked on, including the one I grew up in.

Read the installation instructions yourself that come with the new shower. If you’re installing one that’s preformed acrylic, be sure the base is supported so it will not flex and oilcan as you stand in the shower. This movement causes cracks and leaks down the road.