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Kerdi board is a very commonly used building material, although it does only have a few specific uses. What we want to do today is to take a much closer look at Kerdi Board to figure out exactly what it is.
Once we know what it is, we’re then going to take a look at some of the best alternatives that you can use. So, let’s figure out what you could possibly use instead of Kerdi Board.
What Is Kerdi Board?
Before we start talking about the possible alternatives to Kerdi Board, let’s first figure out what it is. So, Kerdi Board is a very special type of extruded polystyrene foam panel, very similar to something like Styrofoam. These foam panels all have a reinforcement material on both of the face sides and feature fleece webbing.
This fleece webbing allows it to be easily anchored into thin-set mortar, with the reinforcement material making it much stronger. What is very beneficial is that these foam Kerdi Board panels are extremely lightweight, surprisingly durable seeing as they are made of foam, and totally waterproof too.
Kerdi boards are generally used as building panels, and as a multifunctional tile substrate. Simply put, Kerdi Board is generally used to underlay tiles in kitchens and bathrooms.
The main benefit that you get with Kerdi Board, besides creating a waterproof barrier between tiles and walls or floors underneath, is that tiles are very easy to attach to it. That said, this is strictly an underlayment material and it’s not something that you would use for any kind of visible application.
6 Alternatives to Kerdi Board
Now that we know what Kerdi Board is, let’s talk about some of the alternatives that you can use instead of it.
One of the alternatives at your disposal is drywall, which is a common building material that may also be referred to as a gypsum panel, sheetrock, or plasterboard. This is a specific type of panel that is made out of calcium sulfate dihydrate.
This material is a gypsum panel, with a gypsum slurry being formed into a flat sheet and laid in between sheets of backer and facer paper.
In other words, it’s a layer of plaster squeezed in between two sheets of specialty paper. Drywall is most often used to build interior walls and ceilings, as it is fairly cost-effective and easy to work with, plus it looks alright and is also very easy to paint and sand.
Just be aware that, unlike Kerdi Board drywall does not make a good backer for tiles. Kerdi board is a tile underlayment option, whereas drywall is designed to make walls and ceilings that are visually appealing.
Learn more about how Kerdi Board and drywall compare
2. Green Board
We then have green board, which is a commonly used term for a very special type of drywall that is made to be water-resistant. Unlike normal drywall, green board has a much thicker coating of that backer and facer paper on the outside and is also made with an exterior layer of water-resistant wax.
What is interesting to note is that unlike normal drywall, which cannot be used to underlay tiles in kitchens and bathrooms, green board actually can be.
Green board is much more durable than normal drywall and will not start to decay or crumble due to moisture. It’s not the most durable option around in terms of impact resistance, but it does work well for moisture resistance.
With that being said, when compared to Kerdi Board, it’s not quite as resistant to moisture or as durable, and it’s also not quite as easy to work with, especially in terms of setting it in mortar or attaching it to tiles. That said, this material does tend to be a bit more cost-effective than Kerdi Board.
We then have what is known as Schluter-Ditra. This is a special type of underlayment system used for underlying tiles. Keep in mind here that Ditra is the product, whereas Schluter is actually the brand name.
What needs to be said here is that this particular tile underlayment system is specifically designed for use with ceramic and stone tiles, for both kitchens and bathrooms, and more.
These are relatively thin panels that are also flexible and soft, as they are made out of polyethylene, a very special type of plastic. These panels act as both a waterproofing layer between tile and substrate below, as well as the basic underlayment system.
This type of panel is extremely lightweight and easy to work with, and it also comes with free space under the panels to help route excess moisture and vapor away from tiles. It then also comes complete with square cut-back cavities and a grid structure, along with anchoring fleece that is laminated to the bottom, which can then be bonded to the substrate.
In terms of an effective tile underlayment system for high-moisture and high-traffic areas, this is likely one of the best, although it is also very expensive.
4. Cement Board
We then have what is known as cement board, which is a very durable and hard material. This material is made with a cement slurry that is then reinforced with a fiberglass mesh. Therefore, this is an extremely dense, hard, durable, and water-resistant material.
Because it does not contain any organic materials, cement board is very resistant to any sort of direct moisture, rotting, and decay. It also has great weight-bearing capabilities and impact resistance. That said, due to all of these benefits, this material also tends to be rather expensive.
With that being said, it’s also not very easy to install, as it’s very heavy and cumbersome. However, when it comes to moisture-related purposes, such as being used as a tile underlayment for bathtubs and showers, it is one of the better options to consider.
Learn more about how Kerdi Board and cement board compare
Another option that you have at your disposal for simple tile underlayment, especially in areas that don’t see too much moisture, is plywood.
However, if you plan on using plywood as a tile underlayment system in bathrooms and kitchens that see a lot of moisture, it does need to be very high-grade plywood that is rated for moisture resistance.
This material is quite durable, can handle a lot of weight, and is flexible too, so it does work well for high-traffic areas. That said, as far as moisture resistance goes, it’s not quite as good as some of the other options on the list today.
One of the other options that you have at your disposal here is simple concrete. If you are underlaying ceramic tiles, a very flat layer of concrete is a good option to consider, although it does have to be extremely flat and even.
Just keep in mind that although concrete is extremely hard and durable, and features great weight-bearing capabilities, it’s not quite as resistant to water over a prolonged period of time as some of the other materials listed above.
Should You Use a Kerdi Board or One of the Alternatives?
Generally speaking, due to its moderate cost, strength, flexibility, ease of use, and great moisture-sealing properties, Kerdi Board is often considered to be one of the best options for tile underlayment.
That said, if you need something even more durable and moisture-resistant, using Schluter-Ditra – which in fact is made by the same company as Kerdi Board – could be a good choice.
Now that you know what Kerdi Board is and what it is used for, as well as what the alternatives to it are, particularly for underlaying tile, you can make an informed decision between all of the options.