Do I need to waterproof shower walls before tiling?

Table of Contents
    Add a header to begin generating the table of contents

    The majority of the time, tile can be considered waterproof. No, natural stones will not absorb water, but porcelain tiles will not absorb water for the most part. The majority of water will be shed from walls that have ceramic tiles installed on them. On the other hand, grout is a terrible material. Literally. With a few notable exceptions, such as epoxy grout and grout that does not contain sand, grout is composed of sand that has been bound together with Portland cement. Because of this, it behaves similarly to sand in that it can absorb water as it moves across the surface of the grout. This indicates that, prior to constructing your shower, you will need to give some thought to what the water will do when it travels through the grout and lands on the wall behind it.

    The average shower receives the same amount of precipitation as a standard shower head in a single year, which is the equivalent of 2,500 inches. This indicates that waterproofing a shower in the correct manner is not just a recommendation; rather, it is necessary in order to protect a residential or commercial structure from the effects that water can have. The migration of an excessive amount of water into wall cavities can result in expensive structural damage and can encourage the growth of mould, which can cause illness and create a hazardous environment.

    It is imperative that the substrate be properly prepared before even beginning the process of waterproofing the structure. First, you should check to see that the foundation is stable. Building codes require that the floor and frame be constructed properly. The placement of drains should then be carefully planned to ensure adequate water removal. In addition, make sure to check the level and the pitch to ensure adequate drainage.

    Ceramic tile and grout, on their own, are not waterproof despite the widespread belief that this is the case. It is possible for water to break through grout made of cement and make its way through the substrate. Installing a water-resistant membrane just below the tile bonding mortar and as close to the tile itself as you can gets you one step closer to solving the problem of water damage. There are two different kinds of waterproof membranes, including sheet and liquid membranes that are applied.

    Looking for the best tiling renovations? Look no further! Hitch Property Constructions has you covered.

    Tiles Floor FAQs

    Stone and porcelain tiles are the best for the shower floor. Avoid glazed ceramic tiles in this spot, as they tend to be slippery. Also, remember that non-vitreous tiles are not suitable for the shower floor. Only impervious or vitreous tiles should be used in the shower area, as they are relatively more waterproof.

    When water penetrates from tile joints, it leads to debonding of tiles and you certainly don't want that to happen. When you consider a grout there are different types of grouts which you must choose from. For instance, for areas where water is a concern, you must pick water-resistant tile grouts.

    For flooring, Vitrified tiles are the best bet since they are durable and can withstand heavy traffic. For walls, you can choose either ceramic or porcelain tiles as they are non-porous or do not absorb stains.

    Instead of choosing different tile colors, go for different shapes instead. Select two tile designs in the same color and use the grout lines to create patterns. To add more detail to the tiles, choose a grout color that contrasts with the tile. For instance, choose white subway tiles and black grout.

    A small bathroom can actually benefit from a large tile. With fewer grout lines the walls and floor are less cluttered and the room visually expands.

    Sheet Membranes

    Sheet membranes are made out of elastomeric or plastic sheets that need to be bonded to the substrate before tile can be installed on top of them. Some of the sheets come with their own adhesive backing, whereas others call for additional adhesives or cement mortar. Primers are almost always required to be applied to the substrate before pressure-sensitive adhesive-backed membranes can be installed. The drying time for the primer might be at least an hour. Other membranes have to be bonded using a cement-based thin-set mortar, which also needs time to cure completely before it can be used.

    When installing a sheet membrane, it is essential to remember to treat and seal the seams where the sheets come together so that the membrane can continue to function as intended and keep water out. If you want to create a waterproof membrane that is continuous, you need to pay careful attention to all of the transitions and changes in the plane. In most cases, installing prefabricated sheet membranes is not nearly as quick and simple as the manufacturer advertises it to be. Before beginning installation, all of the components, including the membrane, preformed corners, bonding mortar, primer, and sealant, have to be gathered together, and the sheets have to be cut. Sheet membranes are not only more expensive but also require more time and labour to instal.

    Waterproof Shower Walls Before Tiling 1

    Liquid Membranes

    The installation of prefabricated sheet membranes is made significantly simpler with the use of liquid membranes. Primers are not required, there is no need to treat seams, and there is no need to worry about transitions going up walls or through corners. The RedGard Waterproofing and Crack Prevention Membrane is an elastomeric membrane that is ready to use and is applied in the form of a liquid. It forms a continuous barrier that is waterproof and has excellent adhesion. Additionally, it can be utilised to effectively vapour-proof steam rooms as well as gang showers. Brushing, trowelling, rolling, or spraying are all valid methods. Applying a second coat on top of the first will ensure that the floor will have a continuous film that is free of voids. For optimal performance, the membrane should have a thin fibreglass mesh embedded within it to accommodate changes in plane and gaps measuring at least 1/8 inch.

    No Waterproofing: Will this cause shower leaks?

    Shower leaks.

    The last thing anyone wants when they build a new shower. And yet I hear the following questions quite often:

    • Is cement board resistant to water?
    • The majority of the water will be prevented from entering the space by the tile and grout.
    • Our shower does not have any waterproofing because the contractor who worked on it did not do it. Will there be leaks in the shower as a result?
    • We were unaware that the shower was supposed to have a moisture barrier installed in it. Should we make a fresh start?

    The fact that a member of the John Bridge forum had recently posed the question "Is a moisture barrier required?" served as the impetus for writing this post. It was a contractor that he hired to instal his shower, and the contractor advised him that there was no need for it. However, as more details were disclosed and photos were shared, it became abundantly clear that there would be some water damage caused by the showers. It is strongly recommended that you click on the link and read through the post.

    What is a moisture barrier?

    A moisture barrier is essentially a waterproof barrier. Its purpose is to keep moisture from getting through the backer board and into the wall. Acceptable forms of waterproof barriers for a shower are:

    • A sheet of plastic with a thickness of four mils placed behind the tile backer board, liquid waterproofing applied to the surface of the tile
    • backer board, and a membrane sheet that is waterproof placed on the surface of the tile backer board.

    Shower Waterproofing Crash Course

    A plastic sheet with a thickness of four mils that is adhered to backer board cannot be considered a waterproof membrane in my opinion. Why? Because you start by stapling this membrane to the studs, and then you puncture it further by nailing (or screwing) backer board in front of it. However, this method is not only acceptable but also a minimal way to prevent moisture from entering a wall cavity.

    So here's where I draw the distinction between a moisture barrier and a waterproofing membrane:

    • A moisture barrier is an essential component of waterproofing for vertical walls.
    • A waterproofing membrane is required for all horizontal surfaces, including those that slope.

    Moisture Barrier vs Waterproofing

    Now, I'm not the only one who differentiates between waterproofing vertical and horizontal surfaces, but I do think it's important to do so. On all surfaces that are intended to be waterproof, Custom Building Products mandates the application of two coats of their Redgard liquid waterproofing. On the other hand, they also have this technical bulletin that states it is only necessary to apply a single coat to the vertical surfaces of the backer board.

    Similar to the statement that all whiskeys are bourbons, but not all bourbons are whiskeys. Although a moisture barrier can also function as a waterproofing barrier, this does not mean that a waterproofing barrier must also function as a moisture barrier.

    The only thing that is required to prevent water from entering the water cavity is a moisture barrier. If you want to stop water from leaking into a shower, however, you will need to waterproof the horizontal surfaces in a more thorough manner.

    Where you are likely to have shower leaks

    The shower floor, half walls, benches, curbs, and recessed niches are some examples of the horizontal surfaces that are typically found in a shower. These require special attention in order to prevent any leaks from occuring. Two coats of liquid waterproofing, a waterproof sheet membrane, or one of the many different types of foam waterproof products that are currently on the market are all appropriate strategies for waterproofing surfaces of this type. They are responsible for the production of foam recessed niches, corner benches, floating benches, curbs, and shower pans.

    Do you need to waterproof shower walls before tiling?

    Before the year 1960, the typical family home did not have any "shower stalls," but rather bathtubs with walls surrounding them. In the same manner as the rest of the house, these walls were constructed using concrete plaster. On top of that plaster, a second layer of concrete plaster measuring half an inch thick was applied and given the name "mud bed." This was the layer in which the tiles were set, and the edges were finished off with a piece of tile referred to as a "mud cap" (hence the name).

    The disadvantage of using concrete plaster was that it absorbed moisture through the grout lines, which was a common problem. Once inside the wall, the wooden frames soaked up the moisture from the wet concrete, and because there was a lack of fresh air, the studs began to deteriorate, a process that is known as "stud rot.

    After some time, when drywall or gypsum boards were generally recognised, the plaster was eventually replaced with the so-called "green board," which offered the promise of being resistant to mould and water.

    Mold loves cellulose, so it's a good thing they didn't know (or didn't care) that the green, water-resistant paper layer is a product made of cellulose and that mould can grow on cellulose. As soon as the water broke through the coating that prevented water from getting in, the mould was able to start feeding on the gypsum and the paper without any restrictions.

    Check out our range of tiling renovations Melbourne at Hitch Property Constructions.

    Why you need to waterproof a shower for tiling

    It is our opinion and the automatic assumption of the vast majority of people that the most important building concept of any bathroom is that it does what it is designed for and keeps the water where it is meant to go and, more importantly, where it isn't meant to go. This is the most important aspect of any bathroom. This is impacted by the manner in which a bathroom shower is constructed, the materials that are utilised, and the methods that are utilised to waterproof it. Whether the walls are going to be tiled or wet panels, in a shower tray or a bath with a shower, the panels or the backer boards that the tiles adhere to need to sit on top of the edge of the bath or tray. This is true whether the walls are going to be tiled or wet panels. The panels only move downward alongside the tray and continue to the ground in exceptional circumstances such as wet rooms. In wet rooms, the gap between the wall and the floor is sealed with a specialised sealant tape, which is something I'll go over in more detail later. If you want to save money, you can avoid the expense of waterproofing a bathroom, but doing so will end up costing you significantly more money than waterproofing would have.

    Tile Backer Boards

    In the event that tiles are utilised, the appropriate backer board for them to adhere to must be present. Plasterboard is the material that is utilised the vast majority of the time, despite the availability of special tile backer boards on the market. The cost of the component materials is the reason for this. Customers frequently have a set spending limit in mind. A sheet of plasterboard measuring 1200 by 2400 millimetres. A sheet of dedicated tile backer board measures 600 by 1200 millimetres and costs twice as much as a sheet of plasterboard measuring 1200 by 2400 millimetres. This means that the dedicated tile backer board costs an average of four times as much as the plasterboard. This cost can quickly add up when remodelling an entire bathroom, which is something that prospective clients frequently do not anticipate. Plasterboard, either regular or moisture-resistant, is not an appropriate material for use in a damp environment if it is not first waterproofed. This is true whether the plasterboard is ordinary or moisture-resistant. Even if the correct techniques for installing tiles are used, tile grout and a large number of tile adhesives are not waterproof. Tiles themselves are not waterproof. Plasterboard will eventually become ruined because water will seep into it and cause it to become saturated. Installing heavy tiles while keeping in mind that plasterboard can only support 32 kilogrammes per square metre, which includes the tile, grout, and adhesive creates a situation that is just asking for an accident to happen. Imagine being in the shower and having a tile that is 300 millimetres by 600 millimetres and 10 millimetres thick fall off the wall and land on you. Before tiling, plasterboard needs to have a waterproof coating applied to it. It is not uncommon to see bathroom fitters using the green paper-faced moisture resistant plasterboard. This is a very common practise. It is water resistant, but it is not completely waterproof.

    There is no question that the tile backer boards that are specifically designed for use in moist environments are the superior products. Cement board and insulated foam board are the two most common types of materials used for tile backer board. Depending on the product offered by the various manufacturers, both types of tile backer board are able to support between 50 and 200 kilogrammes of weight depending on the material being supported.

    How to build a shower correctly.

    Now that I've discussed the various options for tile boards, I'll move on to discuss the improper way to construct a shower, which applies to showers that are tiled or wet panelled, with the exception of wetrooms. This is the most efficient method of construction. On the walls, instal the tile backer board, which can be plasterboard, cement board, or something similar. Alternatively, instal the wet wall panels. Then, either lower the bath or shower tray into position by lowering it or pushing it into position alongside the panels or boards so that they continue down to the ground. If you are determined to save money in any other way, don't even bother installing a timber frame to support the bathtub. Fill the space between the tray and the panels with silicone seal, and then tile without first applying waterproofing compound if necessary. Proceed to complete the project by grouting and siliconizing. This is doomed to fail at some point in time. In addition to the fact that the wall will be damaged if it is made of timber, you will also experience water leakage due to the wall flexing and moving. In the event that this does occur over time, you will undoubtedly experience wet rot and possibly even dry rot. Unfortunately, this is something that we see on a regular basis when we go to look at potential repair jobs, and there is not much that can be done about it other than redoing the silicone on a regular basis or ripping the entire shower area out and starting over from scratch, depending on how severe the damage is.

    The correct method to follow. If there is going to be a bathtub installed, even a steel bathtub will bend slightly under the pressure of a person plus the weight of water. The flexibility of an acrylic bathtub is significantly higher. Therefore, in order to eliminate any possibility of flexing, the timber frame must be constructed in such a way that it is completely solid. The following explains why this is the case: When everything is installed properly, the shower tray or the bathtub comes in first. After that, the tile backer boards or wet panels are attached to the wall in such a way that the bottom edge of the boards rests on the surface of the bath or shower tray. There should be about a two to three millimetre space between the bottom of the board and the top of the shower tray or bathtub. In the event that wet panels are installed, the space at the bottom will be filled with silicone seal. In order to tile, the boards must first be treated with a waterproofing agent.

    The silicone seal or the waterproofing will fail at the joint of the tray or the bath if there is any flexing of the tray or the bath at all. Because of this, the timber frame for both fittings needs to be constructed in such a way as to prevent any flexing. In most cases, shower trays are required to be firmly embedded into cement mortar or, even better, tile adhesive. If you do things in this manner, your new bathroom should be able to withstand the test of time without any issues.

    We have a wide range of Melbourne tiling renovations to help you choose in creating a new design for your house.

    How to waterproof a shower using tanking kits

    First, let me explain the distinction between tanking kits and waterproofing kits. Tanking kits are designed to prevent water from entering a tank. Tanking kits are more commonly used in the trade because they are more professional products, slightly more difficult to work with but quicker drying, and give better results in my opinion especially when waterproofing plasterboard in preparation for shower tiling. Waterproofing is the name generally used for products that are more commonly targeted at the DIY market. Tanking is the name generally used for products that are more commonly targeted at the trade.

    Before either option can be used, the necessary wall preparation must be completed. First, sweep and vacuum up any dust that may have accumulated. You will be provided with joint sealing tape from whichever manufacturer is chosen at random. Use this all over the walls, particularly in the corners and in the spaces between the board joints.

    Perform this action all the way around the tub. The tape should then be applied in such a way that the edge of one side rests no further onto the bath than the pencil line, while the other side is secured to the wall. Apply the side that will be against the bath first, then use a scraper or another tool with a flat side to force the tape into the corner between the bath and the panel to create a good 90-degree angle, and finally, fit the wall. At the point where it changes from board to bath, the tape should not have any slope in it.

    Tanking scrim tape

    Because of the messiness of these kits, I strongly recommend that you also do the following. Applying low-cost masking tape along the pencil line that runs along the perimeter of the top of the bath or shower tray and up against the edge of the jointing tape is the next step. It should rest next to it rather than on top of it, and there should be a clearance of 1 mm between the two. Obtain some plastic sheets and cover the bath or tray, then secure it with additional masking tape to keep it in place.

    After this step is finished, if the kit includes a primer, apply it to the wall and wait for it to completely dry before continuing. After that, you are able to start applying the compound. Put on some inexpensive, disposable clothing along with gloves and eye protection.

    If the bathroom is constructed out of wood, the floor must first be waterproofed before tiling can take place. This will prevent the rot that would otherwise occur in the subfloor, which is made of timber. When working on the walls surrounding the shower area, you can apply any tanking compound that has been mixed up to the floor material, regardless of whether it is timber or cement board laid on top of the timber floor. This is a frugal method of getting the job done. A decoupling membrane can also be utilised, which is an alternative method that I discussed on the page devoted to the preparation of tiling. The vast majority of them are waterproof, and if the waterproofing is required for the purpose they were designed for, then it is an added bonus that the waterproofing is already done. However, in comparison to liquid tanking, they are quite pricey, and as a result, utilising them is not the best way to complete the task if decoupling is not required. It is important for you to be aware that the manufacturers of luxury vinyl will frequently claim that their products are waterproof. They are not waterproof; water will still seep between the joints even if you seal them. However, the only way you'll be able to get significant quantities of water through these joints is if you immediately step out of the shower and flood the floor with standing water.

    It is highly likely that taking the additional time to waterproof a bathroom is the single most important factor that can result in vastly different prices being quoted for a new bathroom, and the fact that a large and well-known company is doing the job does not guarantee that they will do the work. Some companies even go so far as to provide a description of the work as well as a time frame for it, all while making the claim that they can completely transform a bathroom in just five days. Because of the additional time and money required, waterproofing will not be mentioned at all because doing so would render the quote uncompetitive. You could end up with a bathroom that, despite the fact that it will probably have a nice appearance on the surface, may only last for five years. If it is done correctly, it should last for twenty-five years.

    Scroll to Top