Kerdi Board vs Cement Board Breakdown


Collin Fowler
Collin Fowler is an architect with extensive experience in both commercial and residential builds. He is the lead Building Product Advisor researcher on the latest and most innovative building products on the market.
If you’re looking for the right tile underlayment, it can be a project on its own. You’ll need to not only think about laying out the tile, but you’ll need to feel sure that when it comes to beginning the tiling, it’s going to be able to stay on the wall. In fact, the success of the installation is going to be heavily based on the substrate to which the tile is attached. The underlayment, whether it be the floor, wall, countertop, whatever, all needs to be just ride.
This is vital as this is going to prevent cracks from occurring in the tile itself, but also the grout. Since the underlayment matters so much, you’ll have two major options Kerdi Board vs. Cement Board. So, here is everything you need to know about the two so you can make the best decision on what you should purchase!
Kerdi Board vs. Cement Board: An Overview
Before we begin with the similarities and differences between Kerdi board vs. cement board, let’s first figure out what they both are.
What is Kerdi Board?

Kerdi board was created as a way to help mitigate some of the flaws that cement board has. This material is a multifunctional tile substrate and it is a building panel too. This often gets used for tile underlayment, plus this can be used with bonded waterproofing assemblies. It’s made out of extruded polystyrene foam. This has special reinforcement material on both of its sides. Plus, the fleece webbing within the interior allows for effective anchoring.
What is a Cement Board?

Cement board is one of the more common materials that is generally used for underlying tile. Plus this is usually inside kitchens and bathrooms, plus, this can be used for normal floors too. This is one of the more inexpensive options, which is the main reason why so many people use this.
Kerdi Board Vs. Cement Board: What’s The Difference?
While cement board may be one of the more common substrates out there, Kerdi board isn’t bad either. Let’s dive into the major differences between these two substrates.
Value for Money
A major reason why cement board is very popular is mostly due to the fact that it’s very cost-effective. You can expect Kerdi board to cost about twice as much as the cement board.
Weight
One of the main differences between the cement board vs. Kerdi board is that Kerdi board is much lighter, and therefore usually much easier to work with.
Water Resistance
Kerdi board is waterproof thanks to the ingredients it contains. However, you could technically waterproof cement board as well.
Composition
In terms of composition, a cement board is made out of cement, which has a mesh lining within the middle of it. Kerdi board, on the other hand, it made up of polystyrene. So essentially, one is made from cement while the other is made of a special type of foam.
Stability
There isn’t a major difference when it comes to Kerdi board vs. Cement board in the stability department. Cement board is slightly more durable than Kerdi board. So, if you’re planning to lay this out such as a floor, one that will receive high traffic then cement board would be the right option. However, the cement board could still potentially crack, and if it does, this is going to make a massive impact.
Ease of Application
Kerdi board is significantly lighter than cement board. This immediately means that it will be easier to install too. One person could easily install Kerdi board, while the installation of a cement board may need two people. Plus, if the installation of the cement board isn’t right, then there is a chance of it falling due to its weight.
Fire Resistance
Cement board is far more resistant to fire and combustion compared to Kerdi.
Similarities of Kerdi Board vs. Cement Board
Now that we know there are some major differences between the two, let’s dive into the similarities.
Both Offer Various Sizes
Both of these tile underlayment boards are able to come in a variety of sizes. This is it great as it can suit a variety of spatial requirements and needs.
Serve the Same Purpose
These materials offer the main purpose of functioning as a tile underlayment. These materials can also be used in floor tile underlayment, bathrooms, and kitchens.
FAQ
No, you will not need to install a vapor barrier behind Kerdi Board. This is due to Kerdi Board acting as the vapor barrier.
Kerdi Board is suitable for shower floors.
Kerdi board can act as a great alternative to cement board. However, if you’re putting this on a floor with a lot of foot traffic, then cement board may prove to be more impact resistant.
Kerdi Board vs. Cement Board: Which Should You Choose?
Hopefully, you can now clearly see the difference between Kerdi Board and Cement Board. These two products have the same functionality, but it’s their features that make them both vary. If you’re new to DIYing, then the Kerdi board may be the best choice. However, if you’ve been doing projects for a while, then maybe something as rigid as cement board would be fine. Overall, it’s all about what you’re most comfortable using for your project. These are both great products that essentially both offer the same uses.
Get Smarter About Building Products
Join 50,000+ subscribers and get our 3 min daily newsletter on what matters in the building materials industry.
You might like this

Comparing Different Flooring Options; Luxury Vinyl Plank, Tile, and Carpet
There are a multitude of factors that must be considered when choosing flooring for your living spaces, such as the type of furniture that you plan on using in the room, how the flooring will complement the atmosphere you are trying to create, and whether or not you have children and/or pets. With this in […]

Empire vs Luna Flooring: A Breakdown of Differences and Features
Empire and Luna flooring are two of the leading names in full service flooring installation. Since Empire purchased Luna in 2012, many people think that the two companies are one and the same. However, Empire operates Luna as a distinct brand, and some subtle differences remain between the two lines. Keep reading for a detailed […]

Bass Traps vs Acoustic Panels: What are the Differences?
With the advent of remote work, Zoom meetings, podcasts, and other forms of digital media creation, the need for soundproof spaces has skyrocketed in recent years. With few people able to completely remodel their homes or commercial facilities to improve acoustics, many after-market products are being added to spaces to help improve sound quality. Two […]