Best Cement Boards for the Shower


When remodeling or building a shower, selecting the right backer board is one of the most important decisions you’ll make. Cement backer boards provide a stable, waterproof substrate for shower walls and floors. They prevent moisture from seeping into the framing and drywall behind shower tiles.

There are several cement board brands on the market, each with their own advantages. In this comprehensive guide, we’ll discuss the top-rated cement boards for showers. We’ll compare the leading brands on performance, durability, mold resistance, ease of installation, and cost.

We’ll also provide tips for choosing the right cement backer board for your shower project. With the right information, you can select a top-performing cement board that will provide a stable, long-lasting foundation for stunning shower tiles.

What is Cement Board?

Cement board, also known as cement backer board or wonderboard, is a construction material made of cement reinforced with fiberglass mesh. It is commonly used as a tile backing board for wet areas like showers.

Cement board is made of an extruded cement composite reinforced with embedded fiberglass mesh. This makes it highly water-resistant and durable. It’s able to withstand prolonged moisture exposure without deteriorating.

Tile installed over cement board is less likely to crack or detach, even with regular water exposure. Cement boards provide a stable foundation that resists shifting and expansion better than drywall alone.

Cement backer boards are available in a variety of sizes and thicknesses. Thicker boards provide more durability for floor installations. Boards are installed over a water-resistant substrate like a vapor barrier or existing tile.

When installed and sealed properly, cement backer boards are highly waterproof. They prevent moisture from seeping through to walls or subfloors behind shower tiles. Cement boards won’t promote mold growth either.

Compared to substrates like greenboard drywall, cement backer boards are clearly the superior option for wet areas. Let’s look at why you should choose cement board for your next shower installation.

Benefits of Cement Board for Showers

Installing cement backer board for your shower walls and floors provides a number of advantages over other substrate options:

  • Waterproof – Cement board is highly water-resistant and won’t break down when exposed to regular moisture. This prevents water damage to structural walls behind tiles.
  • Mold resistant – Cement boards won’t promote mold growth, which can be a problem with moisture-sensitive substrates.
  • Durable – Cement board is a tougher, more rigid substrate than materials like drywall. It better resists damage from impacts.
  • Stable – Cement boards provide a stable, crack-resistant substrate for shower tiles. The material resists expansion and contraction.
  • Level surface – Cement board creates a flat, level surface for achieving uniform tile layouts. Joints can be taped and mudded.
  • Fire resistant – Cement board is non-combustible and fire resistant.
  • Codes approved – Cement backer board meets IRC and IBC standards for use as a shower substrate.

When installed properly on walls and floors, cement board checks all the boxes for an ideal shower tile underlayment. It provides the most reliable backing for a waterproof, durable shower with beautiful tile aesthetics.

Best Cement Board Brands for Showers

There are many cement backer board manufacturers to choose from. The top brands include:

1. James Hardie HardieBacker Cement Board

James Hardie HardieBacker is one of the most popular and widely available cement board brands. The original cement backer board, HardieBacker consists of a cement composite reinforced with fiberglass mesh.

HardieBacker comes in 1/4” and 1/2” thicknesses for walls and floors. It can be cut easily with carbide tipped scoring knives. The boards feature tapered edges to help conceal seams.

HardieBacker boards have excellent ratings for mold resistance and fire resistance. Installation is straightforward, either with mesh tape and thinset, or fiberglass drywall tape and modified drywall compound.

Overall, HardieBacker cement board provides great performance at a reasonable price point. It’s one of the top-rated backer board solutions for shower installations.

2. USG Durock Cement Board

Durock is USG’s brand of cement backer board. It’s considered the main competition to HardieBacker cement boards.

Durock is made from a cement composite reinforced with a fiberglass scrim instead of mesh. It comes in the same 1/4” and 1/2” thicknesses.

Performance-wise, Durock offers the same advantages as HardieBacker. It has similar ratings for durability, mold resistance and fire resistance.

Installation is pretty much identical as well. Professionals often report good experiences with both Durock and HardieBacker cement boards.

3. Permabase Cement Backerboard

Permabase cement backer boards are produced by National Gypsum and offer another good fiber cement board option.

Permabase is available in 1/4” and 1/2” thicknesses for wall and floor installations. It can be cut easily with a utility knife or scored and snapped after cutting the mesh.

According to National Gypsum, Permabase has one of the highest mold resistance ratings among cement boards. It also offers great fire resistance properties.

Overall, Permabase boards provide similar performance to Hardiebacker and Durock. Some people find Permabase boards easier to cut and install. It’s another top cement board choice for shower installations.

4. Fiberboard Underlayments

In addition to traditional fiber cement boards, you can also use fiberboard underlayments like Schluter’s Ditra and USG’s Fiberock.

These products combine the moisture resistance properties of cement board with the lightweight versatility of plywood. Fiberboards install just like traditional cement backer boards.

Performance-wise, fiberboard underlayments offer improved flexibility and ease of installation compared to fiber cement. They can only be used for flooring applications.

Overall fiberboard underlayments are great for shower pan floor installations. They provide similar performance to cement board with lighter weight.

Choosing the Best Cement Board for Your Shower

With all the cement board options out there, it can be tricky to select the right product for your shower installation. Here are some tips for choosing the best cement backer board:

  • Select a 1⁄2” thick board for shower flooring. Go with 1⁄4” boards on walls.
  • Make sure the board offers excellent mold resistance and waterproof properties.
  • Choose a brand that’s widely available and popular with tilers.
  • Consider fiberboard underlayment for easier flooring installation.
  • Look for boards that are easy to cut and install. Perforated boards are ideal.
  • Compare prices – cement boards are all similarly priced from the major brands.
  • Check that the board meets ANSI standards for cement board performance.

Taking the time to research and compare cement backer board brands will ensure you select the right product for your specific needs. A top quality cement board will provide the stable, waterproof backing you need for a durable and beautiful shower installation.

How to Install Cement Board for Showers

Installing cement board properly is critical for getting optimum performance as a shower substrate. Here is a step-by-step overview of how to install cement backer boards for shower walls and floors:

Gather Materials

  • Cement backer board
  • Fiberglass mesh tape
  • Thinset mortar
  • Modified thinset (for floors)
  • Cement board screws
  • Foam backer rod (for seams)
  • Utility knife/carbide scorer

Prep the Framing

  • Ensure framing is in good condition, well supported, and spaced 16″ o.c.
  • Install water-resistant barrier like tar paper over wood framing.

Cut Cement Board to Size

  • Measure the shower area and cut boards to fit using a straight edge and utility knife or carbide tip scorer.
  • Place pieces with tapered edges along the perimeter.

Fasten Boards to Studs

  • Place boards over framing and fasten with cement board screws every 8″ along studs and edges.
  • Offset seams between rows.

Tape and Mud Seams

  • Fill gaps and seams wider than 1/16” with foam backer rod.
  • Apply fiberglass mesh tape over all seams and corners.
  • Spread thinset over tape with a trowel to embed.

Prepare for Waterproofing

  • Seal all board penetrations with silicone.
  • Install cement board around the shower threshold.
  • Let mortar fully cure before applying waterproofing.

That covers the basics of securely installing cement backer board for your shower. Be sure to carefully waterproof and flash corners once the board is in place.

Waterproofing Cement Board Showers

Waterproofing over cement board is an extremely important step. Sealing the seams and junctions helps prevent moisture penetration behind shower tiles.

There are two main methods for waterproofing cement board showers:

Liquid Membrane

Apply a liquid waterproofing compound intended for wet areas, like RedGard. Use a paint roller to apply two coats over all cement board surfaces. Extend it several inches outside the shower.

Ensure you seal corners, seams, and floor/wall joints thoroughly. Let the membrane cure fully before tiling.

Cement Board Membranes

Self-adhesive, thin sheet membranes like Schluter Kerdi are embedded into thinset over cement boards. After applying thinset to the board, roll the membrane on from top to bottom.

Seal all seams and shower niche edges with special tape. Apply the membrane onto wall/floor corners to connect them.

Either method creates a seamless water barrier when installed correctly. This keeps the structure behind cement boards 100% protected from moisture damage.

Now let’s look at some frequently asked questions about installing Best Cement Boards for the Shower.

FAQs about Best Cement Boards for the Shower

Should I use cement board or drywall for shower walls?

Cement backer board is far superior to drywall for shower walls. Drywall facing regular moisture will break down quickly. It also promotes mold growth. Cement board is waterproof and provides a durable surface for shower tiles.

What thickness of cement board should be used for a shower?

Use 1/2-inch thick cement board for shower pan flooring. This provides maximum durability and support. Go with 1/4-inch boards on shower walls which don’t require as much rigidity.

Can I install tiles directly onto cement board?

Cement board should not be tiled directly onto. Make sure to apply a waterproof surface membrane or vapor barrier first. This seals the cement board surface to prevent moisture from penetrating the seams.

How do you prepare cement board for tile?

After mounting the boards, fill any gaps and seams with thinset mortar. Then apply fiberglass mesh tape and more mortar to fully embed the tape. Apply your waterproofing membrane once the thinset has fully cured.

Can I install cement board over drywall?

It’s not recommended to install cement board over existing drywall. The irregular surface makes it difficult to adhere and seal the cement board properly. It’s best to remove existing drywall completely before installing new backer board.

How long does cement board last in a shower?

When properly installed and sealed, cement backer board can last the lifetime of the shower or over 50 years. Maintaining solid waterproofing is key to get the most out of cement board. Regularly inspect grout and caulk for deterioration.

Tips for Installing Best Cement Boards for the Shower

Here are some additional tips to ensure your Best Cement Boards for the Shower installation goes smoothly:

  • Carefully plan the layout to minimize seams that require taping/mudding.
  • Use foam backer rod to fill gaps larger than 1/16″ for the best backing.
  • Always use modified thinset mortar for floor applications. It offers better adhesion and support.
  • Be sure to seal around penetrations like shower valves with silicone.
  • Allow thinset mortar to fully cure before applying waterproofing or tiles.
  • Use cement board screws specifically designed for fastening to studs.
  • Buy slightly wider boards and rip them to size to optimize layouts.
  • Apply waterproofing or vapor barrier over the subfloor/framing first.
  • Make sure the framing is in good condition and meets support requirements.
  • Watch manufacturer instructional videos for cutting and installation tips.

Taking the time to properly install your cement backer boards ensures your shower will have a rock-solid foundation for years to come.


Installing the best cement backer boards for your shower provides huge benefits over alternative substrates. Cement board’s waterproof, mold-resistant, and highly durable properties keep shower walls protected from moisture damage.

Top brands like James Hardie HardieBacker, USG Durock, and Permabase provide excellent quality fiber cement boards. They are all great options for achieving professional shower tile installations.

Make sure to carefully seal and waterproof cement board seams for optimal performance. Your thoroughly installed cement backer board will provide the ideal foundation for stunning shower tiles that last for decades.