How To Waterproof A Shower

Water is an essential part of life, but when it comes to water damage, it’s a pain, and downright unsafe for your home. Unfortunately, some builders don’t feel the same way, so many homes are left without proper waterproofing in the wettest place of the home: the bathroom.

If you’re doing a bathroom renovation, the most important thing is to waterproof your shower. Without doing this, you’re leaving your home in danger of water damage caused by constant splashing water and steam.

While it’s a labor-intensive task, waterproofing your shower is vital to keeping your bathroom and the rest of your home safe and even adds equity to the house itself. Keep reading to learn why you should be waterproofing your bathroom and how to waterproof a shower with or without a renovation. 

How To Waterproof A Shower

Is Waterproofing A Shower Mandatory?

Unfortunately, waterproofing isn’t required in every country’s building codes. While it isn’t mandatory, it’s strongly recommended that your waterproof the area around your shower, at the very least.

 Of all of the places in your entire home, your bathroom, particularly your shower must be waterproofed. This is necessary to protect your walls from water damage that penetrates right through walls and can cause mold, mildew, and wood rot, which will spread throughout the entire home. 

Plus, it may surprise you, but your bathroom tiles and the grout that holds the tiles together aren’t waterproof either. They make look like it, but over time, the grout will start to lose resistance to water and will eventually let it seep right into the walls behind.

How To Waterproof A Shower During A Renovation

Waterproofing a shower while your bathroom is already torn apart is much easier and truly more effective than doing it after all of the walls have been put in. Here’s how to waterproof a shower during a renovation:

Schluter Systems Kerdi Board Waterproof Shower Kit

Schluter Systems Kerdi Board Waterproof Shower Kit

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Install A Waterproof Membrane Overtop of The Backing Wall

If you’re installing a new shower or have the ability to get to the walls behind, take this opportunity to fortify the concrete backing wall by adding a waterproof membrane. Concrete may be strong, but it can still be victim to water damage, which is why the concrete backing wall and subfloors of your shower need to be fitted with a membrane to protect it.

Sheet membranes are more expensive and take much more work to install than a liquid membrane, except for the Kerdi Board Kit that comes with all of the adhesives and precut pieces. The benefit is that they can act as subflooring when installed over the shower’s substrate.

Liquid membranes like Liquid Rubber are inexpensive, easily applied, and are more flexible than sheet membranes. They’re easier because it applies on like paint, rather than having to be adhered or screwed on like some sheet membranes. 

Filling In The Cracks

This step requires the most detail of the whole process. After your shower has been installed, you will have to seal all cracks and openings that may be left. This should be done with waterproof caulking like DAP Kwik Seal Plus or Gorilla Glue.

Any cracks or spaces must be sealed off so there’s no chance of moisture penetration. If you’ve used a sheet membrane, you will have to seal in the screw holes and join the walls and floors as well.

Additionally, using the right caulk to seal those spaces will make or break the level of water resistance. Silicone or acrylic caulk is typically more moisture-proof than latex. Over time, latex caulk will start to peel, which can expose cracks and allow water to seep in. Instead, use acrylic or 100% silicone caulk to seal everything off for good.

How To Waterproof A Shower

Waterproofing a Built-In Shower-Tub

If your shower is a shower-tub combination, waterproofing will only involve caulking where the tub connects to the walls and around the base of the tub. However, you can also take some of the additional tips below to improve the water-resistance of your whole bathroom.

Unfortunately, showers in clawfoot tubs don’t apply to any of these methods. So, in this case, the walls should definitely be waterproofed with a tile sealer like epoxy or Liquid Rubber.

They’re beautiful and deep, but clawfoot tubs are more hassle than they’re worth. It’s easier, cleaner, and much safer to have a stand-up shower or a tub that’s build right into the wall.

Other Tips To Waterproof A Shower

Beyond the waterproofing process on the actual shower, there are some other steps you can make to better waterproof your whole bathroom, especially the area around your shower. Again, clawfoot tub showers can’t be waterproofed, since they’re not attached to the wall, so take some of these tips to

Don’t Forget The Ceiling

One of the first places a home will see peeling paint is in the bathroom. Before the paint starts to peel on your porch, after all of that weather, it will peel off your bathroom ceiling, just above the showerhead. This is more common in tub-shower combos than in walk-in showers with prefabricated tops.

Peeling paint is the start of the water damage caused by steam and it’s one of the first signs that you should waterproof the ceilings as well. A clear sealant like Liquid Rubber can be applied onto the ceiling and will never peel from steam.

Prevent Flooding With Better Shower Drainage

Part of waterproofing a shower is preventing floods. From clogged pipes to broken pumps, your shower drainage is solely reliant on the wellbeing of your plumbing. Make sure that your drainage system is in good condition to prevent backed-up plumbing and flooding shower drains.

Provide An Extra Layer By Waterproofing Your Wall Tiles

As we mentioned, tiles and grout are not waterproofed. If you want to give your bathroom walls an extra dose of water resistance, consider applying a clear epoxy sealant or clear liquid membrane over top to completely seal off the walls from all kinds of moisture from water to steam. This also makes cleaning the walls a much simpler task, since it’s a smoother surface.

Gorilla White 100 Percent Silicone Sealant Caulk

Gorilla White 100 Percent Silicone Sealant Caulk

  • 30 Minute Rain-Ready
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  • Won’t Yellow Over Time

Best silicon sealant I’ve ever used (I’m female) — had to re-set and re-balance a toilet, and this is perfection for that. I had to shim the toilet base in several spots, and this covered those little shims completely.