Do You Need a Waterproof Membrane in a Shower

As an Amazon Associate we earn from qualifying purchases.

Protection from water is the most important factor to consider while ensuring the integrity of your showers. According to the IRC (International Residential Code), shower walls and floors should have a nonabsorbent surface. They’ll maximize the lifespan of the shower and keep water fixtures from rotting.

One of the most effective ways to give your shower a nonabsorbent finish is to use a waterproof membrane. But is it necessary to use a waterproof membrane in the Shower? Can you complete your shower construction without it? Let’s find it out.

Do You Need a Waterproof Membrane in a Shower?

Yes, you need a waterproof membrane in your shower to protect it from water damage. While porcelain and ceramic tiles are virtually waterproof, the grout that’s used to install them on the shower floor and walls isn’t.

The use of grout or tile backer is an effective way to hold tiles in place but it doesn’t make your shower 100 percent waterproof. A waterproof membrane is made of hydrophobic material. When installed underneath tiles, it makes a protection layer and displaces water towards the drain.

Not only does it prolong the lifespan of your shower construction but it also prevents water fixtures from rotting. In addition, it also keeps moisture from producing mold underneath tiles over time.

Popular Types of Waterproof Membrane

There are different types of waterproof membranes available in the market including the following.

Foam Wallboards

The foam wallboards are usually made from extruded polystyrene foam. They’re installed in the shower as a tile backer but they also work as a waterproof membrane. In addition, they enhance the structural stability of the shower.

Foam Shower Bases

The foam shower bases are often made of the same materials as foam wallboards but they’re used to waterproof the shower curb. They’re installed between the two layers of mortar, where the bottom layer secures the foam base and the top one keeps the tiles in place.

Sheet Membranes

The sheet membranes can be made with different materials such as PVC, butyl, HDPE, or composite materials. They come in the form of rolls and are installed with the help of mortar.

They offer fully waterproof sealing but they have joints that need to be overlapped. Therefore, the finish of sheet membranes isn’t perfectly flat and it needs to be carefully covered with mortar.

Liquid Membranes

The liquid membranes, as the name implies, come in liquid form and they’re mostly rolled onto shower walls and floors. They offer a perfectly flat and jointless finish and they’re also easier to install than other types of waterproof membranes. That’s why most DIYers prefer liquid membranes.

Benefits of a Waterproof Membrane in the Shower

Here’s a list of benefits that a waterproof membrane offers.

  • A waterproof membrane keeps water from passing through small masonry lines of grouting and reaching underneath the shower. It prevents water leaks, flooding, mildew, and mold from entering the shower structure and reduces the risk of critical damage to the building.
  • It protects expensive water fixtures by keeping them from rotting and prevents tiles from coming loose and allows them to look cleaner for longer.
  • It increases the longevity and structural integrity of the shower structure and ensures that your building meets environmental safety standards.
  • With sound structural integrity, your building can perform better during environmental changes and harsh weather events. It allows you to avoid expensive repairs by using your property insurance.
  • It makes regular maintenance easy and cheap.
  • It allows you to sell out your property easily because you won’t have any water damage in the building to report.

Can You Install a Waterproof Membrane Yourself

While it’s possible to install all types of waterproof membranes yourself, we recommend you hire a professional for that purpose. That’s because it’s not easy to install a waterproof membrane, especially sheet membranes, foam shower bases, and foam wallboards.

They need to be cut to the exact size of your shower floor and walls. Additionally, they also consist of many parts, including the membrane, sealant, bonding mortar, and preformed profiles for corners.

Even a small mistake will lead to incorrect waterproofing installation, which can cause expensive water damage.

Dangers of Incorrect Waterproof Membrane Installation

Incorrect waterproof membrane installation can damage your shower in many ways, including the following.

  • Swelling in the shower floor and walls
  • Build up of mold and mildew between tiles
  • Tiles coming loose over time, increasing the risk of structural damage to your entire house
  • Termites to enter your home and damage insulation

A water leak can lead to any of these situations, even if your shower structure is brand new. As a result, you’ll need to spend a whole lot of money to get your shower repaired and make it waterproof.

That’s why it’s important to hire a professional and licensed installer to install the waterproof membrane in your shower correctly.

How to Know If Your Shower is Leaking

If you notice any of the following signs, your shower is probably leaking.

  • Cracked tiles on the shower floor, especially along the joints
  • Visible cracks and holes in the mortar or grout joining the tiles
  • Damaged silicon seals around your water fixture’s studs
  • A musty smell in your bathroom
  • Stained shower ceiling
  • Constantly damped floors

If you see any of these signs, you should call a professional plumber to get your shower inspected. If a water leak goes unnoticed, it’ll lead to the following severe issues over time.

  • Rotting water fixtures, door frames, skirtings, and floorboards around the shower
  • Visible water damage, like dark spots, on ceilings and floors in rooms adjacent to the bathroom
  • Moisture and dampness in rugs and carpets in rooms around the bathroom
  • Presence of moisture-loving pests, such as silverfish and cockroaches, in your house.
  • Sounds of running water and puddle and pooling water

Final Words

Adding a waterproof membrane to your shower before tiling is critically important. Not only does it prevent damages caused by water but it also improves the structural integrity and your property’s value.

Always hire a professional installer to ensure correct and perfectly sealed installation of waterproof membrane. It’ll allow you to prevent the dangers of incorrect waterproof membrane installation.

Allen Michael is the Founder and Editor of Home Viable, a website that he started to provide readers with tips on home efficiency and automation. He draws on his engineering background combined with his family-of-four experiences for his articles.