How to Retile a Bathroom: A Complete DIY Guide for Beginners

Introduction

Retiling a bathroom is one of the most transformative renovations you can undertake in your home. Tile is the dominant material in most bathrooms, covering floors, shower walls, tub surrounds, and sometimes even full wall surfaces. When tile becomes cracked, stained, dated, or simply no longer reflects your style, the entire bathroom can feel worn out regardless of how well everything else has been maintained. Learning to retile a bathroom gives you the power to completely reinvent the space without the cost of a professional full renovation.

The process of retiling a bathroom is more involved than many other DIY tasks, but it is absolutely achievable for a homeowner who is willing to invest the time in learning the correct techniques and preparing the work area properly. The most common mistakes in tiling projects — uneven surfaces, improper waterproofing, poorly mixed grout, inconsistent spacing — are all preventable with patience and attention to detail. Done correctly, a DIY retile job is indistinguishable from professional work.

This comprehensive guide walks you through the entire process of retiling a bathroom, from removing old tiles and preparing the substrate through selecting new tiles, setting them, grouting, and sealing. Whether you are retiling a shower enclosure, a bathroom floor, or both, the principles and techniques described here will give you the foundation for a successful project.

Preparation: Removing Old Tile and Preparing the Substrate

Before any new tile can go up, the existing tile must come down and the substrate must be assessed and prepared. Tile removal is physically demanding work. Begin by protecting surrounding surfaces — cover the tub or shower floor with cardboard and tape plastic sheeting over the drain to prevent debris from entering. Use a hammer and cold chisel or an oscillating multi-tool to break up and remove tiles. Work methodically from the edges inward, being careful not to damage pipes or electrical components behind the walls.

Once the old tile is removed, assess the condition of the substrate. In shower walls, you should find cement board (also called backer board or HardieBacker), which is water-resistant and the correct substrate for wet area tile. If you find drywall in a shower enclosure, it must be replaced with cement board before tiling — regular drywall, even moisture-resistant “green board,” is not appropriate for wet shower environments. On bathroom floors, cement board or an existing properly installed tile substrate are both suitable bases for new tile.

Repair any damaged areas of the substrate, fill low spots with floor levelling compound, and sand down any high spots to ensure a flat surface. The importance of a flat substrate cannot be overstated — tile laid on an uneven surface will crack at high points and fail to bond properly at low points. Use a long straightedge or level to check for flatness, aiming for no more than 1/8 inch variance over a 10-foot span. For shower walls, apply a waterproof membrane or waterproofing paint over the cement board seams and corners before tiling for an additional moisture barrier.

Choosing Tile and Planning Your Layout

Bathroom tile selection involves balancing aesthetics, functionality, and practicality. For shower walls, larger format tiles (12×24 inches or larger) are increasingly popular because they create a clean, contemporary look with fewer grout lines that can trap soap scum and mildew. Smaller mosaic tiles (1×1 or 2×2 inches) are excellent for shower floors because the increased number of grout lines provides more traction and the small size accommodates the slope toward the drain more easily.

For bathroom floors, porcelain tile is the gold standard for durability. Look for tiles with a Coefficient of Friction (COF) rating of 0.6 or higher for wet floor applications — this ensures adequate slip resistance. Matte and textured finishes are safer than highly polished tiles for bathroom floors. Large format floor tiles (18×18 or 24×24 inches) are a popular current choice that creates a spacious, uninterrupted look, particularly effective in smaller bathrooms.

Plan your layout on paper before you begin setting tile. The goal is to ensure that cut pieces are symmetrical and fall in inconspicuous locations — corners, edges behind the toilet — while full tiles are visible in the prominent centre of each surface. For shower walls, the layout typically starts from the centre of the most visible wall and works outward. For floors, establish a centre point and work outward toward the walls. Dry-lay a section of tile to visualise the finished result and make any adjustments before committing with adhesive.

Setting Tile, Grouting, and Sealing

Use the appropriate adhesive for your application. In wet areas (shower walls, tub surrounds, bathroom floors), use a polymer-modified thin-set mortar rather than mastic adhesive, which is not suitable for wet environments. Mix the thin-set to a smooth, peanut butter consistency and apply it to the substrate using a notched trowel appropriate for your tile size. Back-butter large tiles (apply a thin coat of thin-set to the back of the tile as well as the wall) to ensure complete coverage and eliminate hollow spots.

Use tile spacers to maintain consistent grout joint width — 1/16 inch for rectified tile with tight joints, 1/8 inch for standard joints, or larger for a more rustic look. Check each tile for level and plumb as you work, and use a rubber mallet and beating block to gently tap tiles into full contact with the adhesive. Periodically remove a tile and check the back — you should see approximately 95 percent adhesive coverage on the tile back for wall tiles and 80 percent for floor tiles. Allow the adhesive to cure for 24 to 48 hours before grouting.

Grout selection for bathrooms should prioritise stain and moisture resistance. Epoxy grout is the gold standard for showers and wet areas — it is virtually non-porous, highly stain-resistant, and does not require sealing. Standard cement-based grout requires sealing after installation and periodic resealing. Apply grout with a rubber float, working at a 45-degree angle across the tiles, pressing firmly into all joints. Remove excess grout with a damp sponge, then buff away the remaining haze with a dry cloth after 24 hours. Seal grout and any natural stone tile as the final step.

Frequently Asked Questions About Retiling a Bathroom

How long does it take to retile a bathroom?

A complete bathroom retile (floor and shower walls) is typically a 3 to 5 day project for a DIYer working on weekends. Day one is demolition and substrate preparation. Day two is tiling the shower walls. Day three is tiling the floor. Days four and five allow for adhesive curing, grouting, and sealing. The actual elapsed time from start to finish is usually 7 to 10 days when you account for curing times and the fact that most people work on weekends. Smaller projects like retiling just the floor can be accomplished in a single weekend.

Do I need cement board in a shower?

Yes, cement board (or an equivalent waterproof tile substrate) is required in shower enclosures and tub surrounds. Regular drywall and even moisture-resistant drywall are not appropriate substrates for tiled wet areas because they can absorb moisture over time and fail, leading to mould, structural damage, and tile detachment. Cement board combined with a waterproof membrane at seams and corners provides the appropriate foundation for a long-lasting, watertight tile installation.

What size tile is best for a bathroom?

There is no single best size — it depends on the size of your bathroom and your aesthetic preferences. Larger tiles (12×24 or larger) work well in larger bathrooms and on shower walls, creating a spacious, contemporary feel. Smaller tiles (4×4, 6×6, or mosaic) can work well in smaller spaces and on curved surfaces. For bathroom floors, avoid very large tiles if the room is small, as oversized tiles can make a small room feel disproportionate. A general guideline is that the tile should not be larger than half the smallest dimension of the room.

How do I prevent mould in the grout?

Preventing mould requires both good installation practices and good maintenance habits. Use epoxy grout or thoroughly seal cement grout to prevent moisture absorption. Ensure adequate ventilation — a bathroom exhaust fan that runs during and for 30 minutes after every shower dramatically reduces humidity levels that promote mould growth. Clean grout lines regularly with a pH-neutral cleaner and reapply grout sealer annually. Fix any caulk cracks around the tub, shower pan, and fixtures promptly, as these are entry points for moisture behind the tile.

Can I tile over existing bathroom tile?

Tiling over existing tile is technically possible if the existing tile is well-adhered, flat, and in good structural condition. However, the added height can cause problems with thresholds, door clearances, and fixtures. The additional weight may be a concern depending on your floor structure. In wet areas like shower walls, tiling over existing tile without addressing potential moisture damage behind the original tile can create long-term problems. For most bathroom retiling projects, removing the old tile and starting fresh provides a better, longer-lasting result.

Final Thoughts

Retiling a bathroom is a challenging but deeply rewarding DIY project that can completely transform the look and feel of your home. The key to success lies in thorough preparation, using the right materials for wet environments, maintaining consistent spacing and level throughout the installation, and allowing adequate cure time at each stage. Rushing any step of the process is the most common cause of tiling failures.

Approach the project methodically, invest in quality materials (particularly in wet areas where cutting corners creates long-term moisture problems), and take the time to learn the techniques before you begin. The result will be a beautiful, professionally finished bathroom that you will enjoy for many years to come.

Sources & Further Reading

• The Tile Council of North America — tcnatile.com
• John Bridge Tile Forum — ceramic-tile-advice.com
• Fine Homebuilding: Bathroom Tiling Guides — finehomebuilding.com