Do I Have to Put a Waterproof Membrane on Shower Walls?

Shower leaks are practically the last thing you want to have in your property, especially when the shower is the one you are building new. Despite that, questions like the one in the title keep popping up. While the importance of a moisture barrier in the shower is often questioned, contractors often fail to do their part in informing their clients. 

The wide availability of great products like the Laticrete 9235 waterproofing membraneand the hydro ban waterproofing membrane have done good in opening eyes to the necessity of their use. 

Should You Use a Waterproof Membrane?

Well, to answer the question above and all versions of it, yes, you definitely want to install productslike the 9235 waterproofing membraneon your shower walls for the reasons of shower leak. But don’t take my word for it. 

Here are two things that should be gotten out in the open in support of this recommendation.

First off, cement boards, hardibacker, tile and grout, none of those are waterproof. You may argue by saying that cement boards are hardly known to fall apart in exposure to water. Well no, it won’t. What it would do instead is soak up all the water that reaches it. It will take a while before it dries up but until then it will remain wet.

Is It Absolutely Required?

Waterproofing is required in showers. It is not optional. The waterproof membrane lies right behind the ceramic tile proofing the layers behind it from moisture. This is important because the layers that come after it are backer board and wood or metal framing. Concrete may not be susceptible to moisture but metal and wood framings are. With slow and regular slippage of water, those two layers can grow weak and even rot over a period time. 

This not only weakens the whole infrastructure, but it also leads to significant leaks. What’s worse, you will not have an earthly clue of what’s going on in those layers until the leak has happened and then you will have no choice but to spend money unplanned in fixing your shower wall.

The Possible Scenarios ofNot Using Water Proofing Membranes

There are many types of water membranes in the market today that can be installed with professional tile installation tools, all of which are formulated to prevent water penetration. Now older homes that were built early in the last century were very forgiving to water penetration, but not the houses of today. Being drafty, those houses let the water leaked inside to change into vapor and escape causing no significant damage to the house. 

Hence supposing that you don’t have a waterproof membrane installed under your shower wall tiles, what happens then? There is a number of possible scenarios in which it can end. Shower leakage is the most probable of them. But not having waterproof membrane in the shower walls can also lead to bad mold growth. It can cause dry rot which can compromise the structure of the house. Last but not the least, it can contribute to toxic air being trapped in.