How to Install Cement Board for Tile

Installing cement board is a key step in any tile project, especially in moisture-prone areas like bathrooms or kitchens. It provides a sturdy, water-resistant base that ensures your tiles stay in place and looking great for years. Unlike wood or drywall, cement board won’t warp or mold, making it essential for long-lasting, professional tile installations.

That said, installing cement board takes more than just placing it down. You’ll need the right tools, like a utility knife, cement board screws, mesh tape, and a clear understanding of how to cut, place, and secure it correctly. Mistakes here can lead to uneven tiles, cracked grout, or water damage over time.

This guide will walk you through the entire process, step by step. Whether you're a DIY beginner or an experienced renovator, you’ll find everything you need to confidently tackle any cement board installation and create a strong foundation for your tile work.

Tools Required

Utility knife

Jigsaw

Stapler

Cordless Drill

Taping knife

Trowel

Materials Required

Cement board sheets

Thin-set mortar

Cement board screws

Cement board or fiberglass mesh tape

2 x 4s

Installing Cement Board For Tile – A Step-By-Step Guide

Are you planning to install cement board to support a new tile surface in your home? Whether you’re remodeling a bathroom, upgrading a kitchen, or preparing a laundry room, laying cement board is a crucial first step that provides a stable, moisture-resistant foundation. With the right materials, some planning, and careful attention to detail, this is a project you can tackle yourself. Below, we’ll walk you through the initial steps to set your project up for success.

Buy Your Materials And Tools

Before you begin installation, it’s essential to gather all the necessary supplies and ensure you have the right tools on hand. Starting with cement board, this is your main material and is available in different thicknesses and sizes. The most commonly used and readily available size is 3 x 5 feet with a 1/2-inch thickness, which typically works well for both walls and floors. However, for specific project requirements, such as tight spaces or areas with unique dimensions, you might need smaller or thinner boards. In that case, be prepared to shop around or consider placing a special order through a local supplier or online retailer.

In addition to cement board, you'll need a high-quality thin-set mortar to bond the board to the substrate, cement board screws to fasten the board securely, and alkali-resistant fiberglass mesh tape for sealing joints. For cutting the boards, a scoring knife or utility knife will work for straight cuts, while a jigsaw fitted with a carbide-tipped blade is ideal for cutting curves or holes around fixtures like pipes or outlets. You’ll also need a notched trowel to spread the mortar evenly, and a drill or screw gun to insert fasteners cleanly and quickly.

Some projects might also benefit from additional framing materials, like 2 x 4s, to reinforce weak areas or to provide backing in spots where the cement board needs extra support. Think through your entire project before buying supplies so you don’t end up running to the store mid-installation. If you're unfamiliar with any tools, especially power tools, take the time to review how to use them safely and confidently before beginning your project. A little preparation goes a long way toward making your work cleaner, safer, and more efficient.

Prepare The Space

Once you’ve gathered your tools and materials, it's time to prepare the installation area. This step is just as important as the installation itself. Begin by ensuring the surface is completely dry, clean, and free of debris. Even a small amount of dust, grease, or moisture can interfere with the adhesion of the mortar and compromise the longevity of your tile installation. Use a broom or vacuum to remove dust, and wipe the surface down with a clean cloth or sponge if needed. If there are any spills or residue, make sure to remove them thoroughly.

Next, inspect the surface where you’ll be installing the cement board. Look for cracks, low spots, raised edges, or other irregularities. Any major issues should be repaired before proceeding. For example, in flooring applications, dips in the subfloor should be filled with leveling compound, and any soft or damaged wood should be replaced. On walls, be sure that the studs are level and plumb, a bowed or uneven wall can lead to uneven tile work later on. Use a long level or straight edge to check for inconsistencies and shim or sand down studs as needed.

If you're installing around plumbing fixtures, make sure all pipes are secured and won’t shift during installation. This is also the time to double-check your measurements and layout plan, ensuring any necessary cutouts in the cement board, like for electrical boxes, faucets, or drains, are marked. Proper preparation will not only make installation easier but also improve the strength and durability of your entire tile system. Taking your time now will pay off later with fewer problems and a professional-looking result.

Make Any Interior Adjustments

Before installing cement board, especially during a renovation in a bathroom or laundry room, it’s essential to make all necessary interior adjustments to the space. If you’re placing cement board over existing drywall, such as during a bathroom upgrade, start by removing any fixtures that could obstruct the installation. This includes sinks, vanities, toilets, bathtubs, and even wall-mounted accessories like towel bars or mirrors. Removing these elements gives you unobstructed access to the walls or floors, ensuring a more efficient and precise installation process.

In addition to fixture removal, it’s a good opportunity to make functional upgrades behind the scenes. If your walls are open, consider adding extra insulation for better thermal and sound control, especially in shared walls or exterior-facing bathrooms. You may also want to install additional blocking between wall studs to create better anchor points for securing the edges of the cement board. This small step can greatly improve the board’s stability, especially in corners and around openings. If you plan to replace plumbing fixtures like shower valves or faucets, now is the time to make those changes. Installing cement board around outdated hardware could lead to inaccuracies and extra work later, so it's best to complete those upgrades first.

Keep in mind that installations in specific areas, such as showers or custom-built tubs, will vary depending on the exact placement and size of elements like the faucet, showerhead, or floor drain. If you’re replacing these fixtures later, avoid cutting holes in the cement board based on old measurements that won’t apply anymore. Finalize your plumbing configuration before taking measurements, so your cuts are accurate and your installation aligns perfectly with your new setup.

Waterproof If Needed

While cement board is moisture-resistant, it’s not completely waterproof. That means in wet areas like showers, tub surrounds, or bathroom floors, an additional waterproofing layer is often necessary to protect your tile installation from long-term water damage. If you’re installing cement board over existing drywall, particularly in areas exposed to direct water contact, it’s critical to apply a waterproofing barrier before you begin placing the cement board.

One of the most commonly used waterproofing options is a plastic sheet or moisture barrier, which acts as a physical layer between your wall and the cement board. If you're using plastic sheeting, try to use one continuous piece to reduce the risk of leaks at seams. Staple the sheet directly into the wall studs, keeping it snug and neatly folded into all corners and crevices. This will help prevent tearing when the cement board is installed on top. Pay close attention to the fit in tricky areas, like corners, edges, or around plumbing fixtures, where loose or bunched plastic could result in vulnerabilities later on.

Alternatively, some renovators choose to apply a liquid waterproofing membrane or roll-on sealant directly onto the cement board after it's installed. This method is often used in high-moisture areas like steam showers, as it creates a fully sealed surface when properly applied. Either method, plastic sheeting or liquid membrane, offers valuable protection against water seepage that can lead to tile failure, mold, or structural damage. Choosing the right waterproofing method for your space depends on the layout, your experience level, and how much moisture the area is likely to face. Taking the time to waterproof correctly will go a long way in preserving your tile installation for years to come.

Cut And Prepare The Cement Board

Once your space is properly cleaned, prepped, and any necessary interior adjustments are complete, the next major step is to cut and prepare your cement board sheets for installation. This step marks the final phase of your prep work before securing the boards to the wall or floor. Fortunately, while cement board is durable and rugged, it’s not as difficult to cut as actual cement tile or ceramic tile. With the right tools and a little patience, you can shape it to fit your space accurately and cleanly.

To begin, measure your walls or floor carefully and mark where each sheet will go. If you're working around fixed features like bathtubs, toilets, cabinets, or vanities, be sure to account for these in your measurements. Use a jigsaw with a carbide-grit blade to make any necessary custom cuts, such as notches along irregular wall edges or openings for plumbing fixtures like sink pipes or faucets. Jigsaws are especially useful for rounded or detailed cuts, allowing you to maneuver easily around obstructions while keeping control of your cut lines.

For straight cuts, especially when trimming full panels to size, you can use a utility knife and straightedge. Score the board along the cut line using firm pressure, then snap the board at the scored line for a clean break. Repeat the scoring process on both sides for a thicker cement board to ensure a smooth separation. After cutting, be sure to sand down any rough edges with a sanding block or file. Smoothing these areas will help the panels fit together more seamlessly and reduce the risk of snagging or chipping during installation.

Accuracy is key when cutting cement board. Ensure that each piece fits snugly into its designated area, with minimal gaps between sheets. Tight seams help prevent moisture from penetrating the underlayment and reduce the need for excessive taping or mortar during the finishing stage. This is especially important in wet zones like bathrooms or laundry rooms, where moisture protection is critical.

Once all your pieces are cut and smoothed, lay them out in the space dry (without adhesive) to double-check your measurements. This “dry fit” lets you confirm that every panel fits perfectly, lines up with your fixtures, and follows the room’s layout as planned. Making adjustments at this stage is much easier than after the adhesive is applied. When you're satisfied with the arrangement and cuts, you're ready to move on to installing the cement board securely in place.

Apply And Secure Cement Boards

Once all your cement board panels are measured and cut to fit your space, it’s time to move into the installation phase and begin securing them to your walls or floors. The method you use to secure your boards will depend on the surface, whether you’re applying the cement board to a flat floor area or mounting it vertically on walls. Regardless of where the board is going, the goal is to create a strong, even, and secure base that won’t shift under pressure or break down over time, especially in high-moisture areas like bathrooms and laundry rooms.

If you're installing cement board on the floor, begin by applying a layer of thin-set mortar to the subfloor. Use a notched trowel or tiling sponge to spread the mortar evenly across a section large enough to place one full cement board sheet. It’s important to work in manageable sections so the mortar doesn’t begin to dry before you’ve had a chance to set the board. Press the cement board firmly into the thin-set, using a slight rocking motion to ensure full contact between the cement board and the mortar bed. For added strength and stability, apply a bit of thin-set to the edges of the board before placing it next to another panel, this helps to minimize movement and gaps at the seams.

Once the board is placed onto the mortar, you’ll need to secure it further using cement board screws, specifically designed to penetrate and anchor the board without cracking it. Drive screws around the edges and across the surface, making sure the screw heads sit flush with or slightly below the board’s surface, never raised above it. Screws should be spaced about 6 to 8 inches apart and positioned about an inch from the edge. This ensures a firm hold without compromising the integrity of the board.

For vertical applications like walls, the process is a bit different. You won’t use mortar behind the boards, instead, use a cordless drill with cement board screws to fasten the panels directly into wall studs. Start by holding each panel tightly against the wall frame, making sure it’s aligned correctly and flush with adjacent boards. Insert screws in a similar pattern, no more than 6 inches apart, and ensure they don’t break through the surface. Use a level as you go to check that your boards remain straight and square. Making adjustments early will save you from problems later when it's time to install tile.

Tape Up And Apply Mortar To The Seams

Once all your cement board panels are attached securely, you’ll need to seal the seams between them to create a strong, continuous surface. This step is crucial to preventing moisture from seeping into the gaps, which could compromise both the cement board and your tile installation over time. Use alkali-resistant fiberglass mesh tape specifically made for cement board. Begin by pressing the tape directly over the seams where two or more boards meet.

Next, apply a layer of thin-set mortar over the taped seams using a taping knife or flat trowel. Start with a thin, even layer to help the tape adhere, and then press the tape firmly into the mortar. Follow that by applying another layer of mortar over the tape, smoothing it out so it’s level with the rest of the board surface. This creates a seamless transition between boards and strengthens the connection to withstand movement and moisture. Be sure to feather out the edges of the mortar so there are no raised ridges that could affect tile placement.

After taping and mortaring all seams, allow the surface to dry completely as recommended by your mortar manufacturer. At this point, your base is solid, moisture-resistant, and ready for tile. Whether you're creating a cozy backsplash, a high-end shower surround, or a durable tiled floor, you're now fully prepped to move on to the exciting part, laying your tile. For a flawless finish that lasts for years, install durable and stylish LiLi Tile products. With their wide range of colors, patterns, and finishes, LiLi Tile is the perfect choice to bring beauty, character, and long-lasting performance to your newly prepared surface.