Home » How To Waterproof A Shower Floor Before Tiling? (Easy Ways For Beginners)

How To Waterproof A Shower Floor Before Tiling? (Easy Ways For Beginners)

Tile floors are the most popular option for bathrooms. In part, this preference is due to the fact that tiles are considered to be impervious to the water and steam to which they will be exposed in the bathroom.

This belief is partially true since they are very effective in combating water and humidity, they are also easy to clean but they are not 100% waterproof.

The grout that surrounds them is a porous material that will allow water penetration into the subfloor. You can treat the joints with a permanent sealer, this will not prevent water from seeping in, it will only slow down the process.

But do not worry. In this guide, we are going to share with you all the secrets of waterproofing tiles so that you can have maximum efficiency when implementing your bathroom.

Importance of Waterproofing Shower Tiles

Tiles will always be the most resistant option against water and humidity for shower floors, bathtub surrounds, or bathroom floors.

But water vapor is an invisible and implacable enemy that will gradually seep through the pores of the tiles. In addition, a humid environment conducive to mold and mildew will be generated.

You should also take into account that water leaks will cause water vapor to gradually seep through the walls.

It is a very common mistake not to take the necessary care in isolating water when we install our tiles.

It is a big mistake that the tiles will be completely waterproof. You must be meticulous and do whatever it takes to run every isolation system within your reach.

If you don’t, humidity sooner or later will win the battle, and repairing water leaks will be more expensive than waterproofing systems with which you can save not only money but also many headaches and worries.

The Problems That Humidity Brings

The problems that humidity brings
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Mold on The Tiles

Mold on bathroom tiles is the most common problem we have to deal with. Mold is the cause of many ills, such as respiratory problems, sinus infections, dermatitis, allergies, and greatly complicates the situation of people who suffer from asthma at home.

Insects And Pests

Another of the big problems due to humidity in bathrooms is insects and pests. Carpenter ants or termites are a great threat to structural parts of the house. They may be insignificant in size, but uncontrolled insect infestations can cost you huge amounts of money.

Damage to The House

The best thing to prevent insects and mildew is to seal your tiles as soon as possible, but most people dismiss this measure or leave it for later and never get to seal the bathroom floors and walls.

The humidity will slowly eat away at the structure of the door frames, and it will settle in the beams and central parts of the house. You won’t have how to anticipate it if you don’t execute a moisture seal beforehand. The water will filter little by little and will end up rotting the wood and even seeping through the cement.

The damage is so severe that it can affect the entire level of your home. When the tiles are not sealed, the water passes through the substrate, accumulating in the substructure of the house. All the material in your house will start to crack and when you notice that the bathroom floor is moving, or cracks appear in the plaster seams, it will be too late.

It is true that there is a solution for everything, but it is always best to prevent evils instead of finding a remedy for them. That is why the correct sealing of the tiles in your home is a necessary measure that should not be neglected or underestimated.

Methods to Insulate And Waterproof Bathroom Tiles

Methods to Insulate And Waterproof Bathroom Tiles
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There are four most popular methods to protect the walls of your house and its structure against humidity. Here we will talk about each of them.

Method 1: Shower Pan liner

Liners for shower trays are the best-known option to prevent water from accumulating on the subfloor of your shower and bathroom.

The shower floor is constantly exposed to water and it is impossible for it not to seep in and rot the structure of the floor. That is why you should use a shower tray.

The shower trays contain the water that comes through the cement. The method consists of installing a mortar bed on the subsoil. Installs at an angle so you can drill holes in the drain.

At the same time, a waterproofing layer is placed on top of the slope and attached to the drain. Typically these pan liners are made of PVC, copper, lead, or chlorinated polyethylene.

You cannot apply the tiles directly to the tray liner, so a mortar bed needs to be installed for proper load distribution. Tiles must be installed with a thin-set mortar.

This is the most common method but not necessarily the most effective, as water can penetrate through and around the base of the mortar. If the amount of filtered water is not significant, you won’t have a problem, but sooner or later all that moisture will end up breaking down the mortar.

Method 2: Hot Mop

The waterproofing process by means of a mixture of cement, felt, asphalt, and fiberglass mesh is called hot mopping. This mixture is used to create a liner in the shower tray.

The asphalt must be heated in order to later join layers of tar paper with which the surface of the tray will be covered. After finishing the hot mopping process, the tiles are installed with the same thin-set mortar as the interior technique.

This is still an old technique that has been used for decades but at the same time has lost its validity thanks to the technological advances and materials that we now have.

However, we must say that it is a very practical method since the process is fast and very economical. Being a method that is applied in a liquid way, it has no limitations in terms of the size and shape of the pan.

Method 3: Liquid Waterproofing Membranes

Liquid waterproofing membranes
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A liquid membrane is a liquid product that serves to waterproof the area where it is applied. In general, more than one layer has to be applied and its thickness will depend on the material you want to waterproof.

The method is similar to when we have to apply a coat of paint or sealer to the paint. It is always necessary to wait for the first coat to dry before applying a second coat.

This product is not just for the shower floor. It can also be used on walls, in the corner of the bathtub, and even in bathroom elements such as walls, niches, shelves, and even in the cracks that form between the grout if several layers are applied. You can apply it with a roller or brushes.

It is the simplest and most economical option among the modern options that we have today.

Method 4: Sheet Membranes

Laminar membranes are made of plastic or elastomeric. It is attached to the substrate with some adhesive or a thin-bed mortar. These sheet membranes must be laid before you install your bathroom tiles.

These sheets are very practical since they must be placed to measure and fit perfectly with the tiles. It is a delicate job and takes some time, but the result is perfect since you will not leave a single space without protection.

These sheet membranes not only cover bathroom floors but can also be placed on bathroom walls and exterior parts of other rooms. It will slow the advance of humidity in any room.

Many people also use them as a sound insulator, since the material they are made of is perfect for soundproofing a room.

With this material, you can place co-mural walls without fearing that the humidity in your room will end up destroying the decorative paper that you would like to have so much.

You should keep in mind that the term “waterproofing membrane” should not be taken literally, since there is no element that is 100% waterproof. Steam will go through any material, but what these sheets do is slow the passage of steam.

There are 3 levels of vapor retarders. Most waterproof membranes are level 2, although we will also find some level 3 materials.

The most popular and effective waterproof membranes are tile foam backer boards and waterproof foam shower liners.


Putting an end to water leaks and the constant humidity generated by the bathroom and other areas of the house may seem like a daunting and even impossible task. But the truth is that there are several methods to combat humidity and put an end to those peeling walls or leaks. unwanted through the walls.

You can resort to traditional methods, but we advise you to make use of new advances in construction and decoration materials. With elements such as liquid membranes or sheet membranes, you can feel safe and even more creative when decorating the bathroom, without the fear that in the near future, you will have to deal with the damage generated by humidity.

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