How to Seal Your Steam Shower Windows

Imagine that the personal steam spa sanctuary you have in mind is one where the outdoors seems to be one with indoors. Expansive windows bring sunlight and greenery inside. As you step into your glass enclosed steam shower, and billowy steam fills the space, you bask in the sunny green-tinted mist and feel the weight of the world leave your shoulders…

That vision is totally doable as long as you – or rather your installation professional – properly seal your steam shower windows and doors.

So, let’s talk about it.

Why is sealing steam shower windows and doors so important?

Sealed windows and doors mean that your steam shower will do what it’s supposed to do: provide you with a steam room experience in an enclosure where steam doesn’t escape and drafts can’t get you.

There are two aspects to ensuring that perfect steam shower experience:

• Windows in your steam shower enclosure that face and may open to the outside
• The glass windows, panels and doors around your steam shower enclosure

Let’s explore both and how to ensure each is properly sealed.

How to Seal an Exterior Window in a Steam Shower

A poorly insulated window anywhere in your home is problematic. Even more when you have an exterior window in your steam sanctuary. Not only can it lead to energy loss, but also to uncomfortable drafts that completely take away from your relaxing SteamTherapy wellness session.

An exterior window connects the inside of your home to the outside; it visually brings the natural world into your home. However, since it interacts with the outdoors, it also has to deal with temperature changes that can stress the window materials through expansion and contraction.

Furthermore, according to the Second Law of Thermodynamics, heat naturally moves toward cold surfaces. If your exterior steam shower window isn’t properly sealed, that steamy vapor will escape outdoors or penetrate the window itself. 

Advice on Sealing Your Steam Shower Exterior Windows

So you can experience the outdoors in your steam room on your terms only (i.e., the steam stays in and the cold air stays out), here is advice for dealing with those exterior windows.

Kris Lee, MrSteam Regional Sales Manager who started out in technical support, explains that for maximum protection you should ensure that your external window is composed of double paned glass to prevent any heat or cold from coming in or going out.

The editors at Fine Homebuilding magazine encourage the use of vinyl-clad windows housed in a wooden jamb, cement backer board, a waterproof membrane, and a good quality silicone caulk. About the window, they explain,

“The vinyl provides maintenance-free protection from moisture for the window itself. The all-wood jamb provides a flat and sound base. Make sure that you locate the window outside the range of the spray from the showerhead.”

And,

‘When the tile is complete and the grout is sealed, use a good silicone caulk where any two planes come together, like where the window meets the newly tiled jamb.’

They also recommend checking every year to anticipate cracked joints that you might caulk or grout if necessary.

If you want to review the topic with your steam shower installation professional, we recommend reviewing Waterproofing a Window in a Tiled Shower as well as the Tile Council of North America (TCNA) Frequently Asked Questions about Showers and Steam Rooms.

How to Seal the Glass Windows, Panels and Doors Around Your Steam Spa for the Best Puffy White Steam 

Next is sealing the glass windows, large glass doors and side panels that face inside your home and allow even more light into your steam shower.

Your personal steam shower needs to be enclosed and insulated to keep the soothing steam in place. It should be equipped with a water-tight shower door, too. And although the shower space needs to be water-tight, it does not have to be air-tight.

>> See 15 Tips to Consider Before Installing a Home Steam Shower

In fact, some air infiltration, especially around the shower door, allows you to see the steam form.  “When your shower is completely water-tight, you get that puffy white vapor that is integral to the steam experience,” says Lee. "Create a water-tight seal steam shower door seal--rather than just an air-tight one--to get the best puffy white steam."

>> See How To Design a Steam Shower Bathroom: Corey S. Klassen Explains

Advice on Sealing Glass Windows, Panels and Doors

According to Lee, it’s best to seal doors and glass panels with a glazing gasket or strips. These gaskets or strips are made of rubber; they go on each side of the glass, holding it in place while keeping moisture in the shower area.

Similarly, add a silicone weather strip at the bottom of the glass door for a better seal.

The editors of Buildipedia say the key to successfully installing waterproof glass panels is to lay down a thick bead of silicone caulk on shower curbs and side rails, as well as any joints where the frames meet the walls.

>> See How to Install a Glass Shower Enclosure for more tips.

Bonus Tip: How to Ventilate Your Sealed Steam Shower

So you’ve taken care of properly sealing all your windows, glass panels and doors, and can go about regularly enjoying all of your steam shower’s steamy goodness. Here’s how to easily let that steam out when you’re done:

1. Turn on your shower to condense the remaining steam in the enclosure before stepping out. 
2. Use an exhaust fan. Standard exhaust fans (located outside of your steam shower) will remove the moist air from your bathroom. 
3. Install a louver. When opened, a louver will let air out of your steam shower so the exhaust fan can take care of it.

Reminder: No heating, venting or air conditioning devices should be installed inside the steam room!

>> See Best Practices for Using and Ventilating Your Steam Shower

In short, if you do have windows in your steam shower, you don’t need to worry. As long as they are properly sealed, they won't in any way detract from your steam room experience. 

What Other Steam Shower Questions Can We Help You With?

At MrSteam, we’re dedicated to answering all of your questions regarding steam room installation and design. If you have questions about steam, let us know in the comments. We want you to fully enjoy the health and wellness benefits of steam. 

For more information on anything steamy, please visit www.mrsteam.com.

 Note: this article was originally published on 07/08/2015 and has been updated.