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How To Waterproof A Window In A Shower

Bathtub window sealed

It has been a long day at the office and all you want is to take a hot shower. You start the water and get the shower all steamed up and step into it, only to notice some dark spots on your shower tile. Once out of the shower, you get your tile cleaner out and start to scrub the dark spots off your tile grout. As you work your way up, you begin to realize that your shower window has been exposed to the outside elements, and is causing mold growth from a water leak.

You get out of the shower as you have made your discovery after cleaning it and research the question: How to waterproof a window in a shower? Caulking and sealing the window is vital to waterproofing the shower window.

Following the steps listed below will allow you to ensure that your shower window is waterproofed. Let’s take a look.

Single window in the shower

What’s Involved

There are a few steps that you will want to follow in order to ensure that the shower window is properly sealed and waterproofed. Keep in mind, a window will always need consistent maintenance. Let’s take a look at what we can do to make this happen.

  • Make sure that your window is higher than your shower head. This prevents water from getting into the window frame and seals. If your window is below your shower head, the window will need more maintenance.
  • Choose the right window. We recommend windows with PVC trim.
  • Make sure to run your waterboard up to the jamb and properly seal it with caulk.
  • Wrap the entire waterboard and area around the window with a latex-modified thinset. The thinset is your waterproof membrane.
  • Install a window sill on a slight slant so that any condensation or water will run off the window sill and not puddle up.
  • Run your tile all of the way up to the jamb after you have installed the window sill.
  • Caulk and fill every hole and crevice.

Following these steps will allow you to ensure a secured and waterproof window in the shower.

Sealed windows in the bathroom

How Much Does It Cost to Waterproof a Window in a Shower

Believe it or not, sealing a window in the shower can be relatively inexpensive. Your national average cost is $44 to $108 per window. The materials are typically the cheaper part of the process. The labor cost is what drives the varying costs. Keep in mind, it is not the best idea to seal or reseal a window for your shower by yourself.

It might seem like an easy cost-saving project, however, having a professional contractor that knows what they are doing will save you from future headaches. Water leaking into your window, water getting into your walls, or even mold and mildew growth can happen if it is not fixed properly.

Depending on the window type and installation, you may decide to replace the window instead to prevent continuous maintenance.

Other Recommended Maintenance

If it looks like the window leaks when it rains it can be several reasons. These reasons are poor insulation, wall leaks, improper overhangs, or clogged gutters to name a few. The easiest thing to do is paint/caulk the exterior.

While you are searching for leaks within the shower window, you should also check for mold. Mold can show up in the home. Builder error, an actual window leak, or even too much humidity due to the shower can cause mold growth. Keep an eye out for it when you are checking the shower window and get rid of it as soon as possible.

Another area that you will want to check once the shower window has been inspected and repaired are your outlets. Making sure that the outlets in your bathroom are GFCI and grounded is important to avoid electrocution. It’s recommended to double-check the outlets as you are making other bathroom repairs.

Shower windows

When Do I Call A Professional

Call a professional if you have a leak and it is from the shower window or another area near there. Typically, the sealant around the window frame might be cracking or coming undone due to weathering and moisture, however, some pipes running through the walls could also be a leaking issue.

Thus, you should hire a professionally licensed contractor to check the walls and the framing around your shower window. Hopefully, it is something as simple as fixing the sealant, but it can be more than that. Also, having a professional take a look at your shower window issues is a great idea as they can be tricky to maintain and take care of and you don’t want someone who is not trained to do this. It can lead to more repairs down the road and you don’t need the headaches or the expense.


When installing or repairing shower windows, you will always want to consult a professional first. It is highly recommended that anything dealing with a window, that you utilize a home inspection service as well as a professional licensed contractor as they know the building codes for window installations in your area.  Call Waypoint Property Inspection to inspect your home in Tampa, St. Petersburg, Lakeland, Orlando, Palm Beach, Ft. Lauderdale, and surrounding areas.