Best Grout for Shower: Epoxy, Urethane, and Cement Options Compared

Choosing the right grout for your shower is one of the most important decisions in a tile project. The wrong grout leads to mold, staining, cracking, and water damage behind your walls. The right grout stays clean, resists moisture, and keeps your shower looking fresh for years without constant maintenance.

This guide breaks down the three main types of shower grout — epoxy, urethane, and cement-based — so you can pick the best option for your budget, skill level, and maintenance preferences.

Why Shower Grout Matters More Than Any Other Grout

Showers are the most demanding environment for grout in your entire home. Every time you shower, the grout is exposed to hot water, steam, soap scum, body oils, shampoo chemicals, and temperature swings. Water sits in grout lines, soaks into porous materials, and creates the perfect breeding ground for mold and mildew.

Standard grout that works fine on a kitchen floor or a backsplash can fail within months in a shower. Cement grout without a sealer absorbs water like a sponge. That trapped moisture leads to mold growth inside the grout, darkening and discoloration, and eventually the grout crumbles and falls out. Once grout fails, water reaches the backer board and framing behind the tile, causing far more expensive damage.

Epoxy Grout: The Best Choice for Showers

Epoxy grout is the gold standard for shower installations. It is made from epoxy resins and a filler powder rather than Portland cement. When the two components are mixed, they undergo a chemical reaction that produces an incredibly hard, non-porous, waterproof material.

Why Epoxy Is the Best

• 100% waterproof: Epoxy does not absorb water at all. Moisture sits on the surface and runs off rather than soaking in.
• Mold and mildew resistant: Because no moisture penetrates the grout, mold has no environment to grow in.
• Stain proof: Coffee, wine, hair dye, soap scum — nothing penetrates epoxy grout. Stains wipe right off.
• No sealing required: Unlike cement grout, epoxy never needs to be sealed. It is impervious from day one.
• Extremely durable: Epoxy grout resists cracking, shrinking, and chemical damage far better than cement grout.
• Color consistency: Epoxy grout maintains its original color for the life of the installation. No fading, darkening, or discoloration.

Downsides of Epoxy Grout

• Difficult to work with: Epoxy grout sets up fast (usually 30 to 45 minutes of working time). Once it begins to harden, it becomes extremely difficult to clean off tile surfaces. You need to work in small sections and clean as you go.
• More expensive: Epoxy grout costs $5 to $12 per pound, compared to $1 to $3 per pound for cement grout. For a typical shower, expect to spend $40 to $80 on epoxy grout versus $10 to $20 on cement.
• Not beginner-friendly: The fast working time and sticky consistency make epoxy grout challenging for first-time tilers. Practice on a small section or scrap tiles before tackling your shower.
• Can look plastic: Some people dislike the slight sheen of cured epoxy grout compared to the matte look of cement grout.

Best Epoxy Grout Products

• Laticrete SpectraLOCK Pro: The industry favorite among professional installers. Excellent color selection, consistent performance, and a workable consistency.
• Starlike EVO: A high-end Italian epoxy grout known for beautiful color options, including metallic and glitter finishes. Slightly easier to work with than some competitors.
• CEG-Lite by Prism: A more budget-friendly epoxy option that is easier to work with than traditional two-part epoxies.

Urethane Grout: The Best Middle Ground

Urethane grout (also called polyurethane grout) is a premixed, single-component grout that offers many of the benefits of epoxy without the difficulty of working with a two-part system. It has gained significant popularity in recent years as a shower grout option.

Advantages of Urethane Grout

• Water resistant: Urethane grout has very low water absorption, though not quite zero like epoxy. It is far more water resistant than cement grout.
• Premixed convenience: No mixing required. Open the tub and apply. This alone makes it much easier to use than epoxy.
• Long working time: Urethane grout stays workable for hours, giving you plenty of time to apply and clean without rushing.
• Stain resistant: While not completely stain-proof like epoxy, urethane grout resists stains far better than cement.
• No sealing needed: Like epoxy, urethane grout does not require periodic sealing.
• Flexible: Urethane grout has slight flexibility, which helps it resist cracking from minor movement and settling.

Downsides of Urethane Grout

• Not fully waterproof: While highly water resistant, urethane grout does absorb a small amount of moisture over time. In a well-ventilated shower, this is rarely a problem.
• Expensive: Urethane grout costs about the same as epoxy, typically $5 to $10 per pound.
• Soft when wet: Urethane grout softens slightly when wet, making it more susceptible to damage during cleaning. Avoid abrasive scrubbing.
• Limited availability: Fewer color options compared to cement or epoxy grout, and not all home improvement stores carry it.

Best Urethane Grout Products

• Bostik TruColor: The most widely available urethane grout. Excellent color consistency and easy to apply. Comes in a range of colors suitable for most projects.
• Prism SureColor: A reliable urethane option with good stain resistance and color stability.

Cement Grout with Sealer: The Budget Option

Cement-based grout is the traditional choice and by far the most affordable. When properly sealed, it can perform adequately in a shower, though it requires more maintenance than epoxy or urethane options.

Sanded vs Unsanded Cement Grout

Sanded grout contains fine sand that adds strength and prevents shrinking in wider joints. Use sanded grout for grout lines 1/8 inch and wider, which covers most shower floor and wall tile installations.

Unsanded grout has a smooth texture and is used for grout lines narrower than 1/8 inch. It is common with tightly spaced wall tiles and mosaics. Unsanded grout is also gentler on polished marble and other soft, scratch-prone stones.

Why You Must Seal Cement Grout

Cement grout is porous. Without a penetrating sealer, it absorbs water, soap, and everything else that touches it. In a shower, unsealed cement grout will develop mold, stains, and deterioration within months.

Apply a penetrating grout sealer (not a topical sealer) 28 days after grouting, once the cement has fully cured. Reapply the sealer every 6 to 12 months. Popular sealers include Aqua Mix Sealer’s Choice Gold, StoneTech BulletProof, and Miracle Sealants 511.

Advantages of Cement Grout

• Very affordable: $1 to $3 per pound. A shower can be grouted for under $20 in materials.
• Easiest to work with: Long working time, easy to mix, forgiving to apply, and simple to clean off tile surfaces.
• Widest color selection: Dozens of colors available from every manufacturer.
• Easy to repair: Damaged cement grout can be scraped out and replaced. Epoxy and urethane repairs are much more difficult.
• Available everywhere: Every hardware and home improvement store carries cement grout.

Downsides of Cement Grout in Showers

• Requires sealing: You must seal cement grout initially and reseal it regularly. Many homeowners forget, leading to staining and mold.
• Absorbs moisture: Even sealed cement grout absorbs some water over time. Heavy shower use eventually overwhelms the sealer.
• Stains easily: Soap scum, hair dye, and body oils stain cement grout, especially if the sealer has worn off.
• Cracks and crumbles: Cement grout is rigid and brittle. Normal house settling, temperature changes, and minor movement can cause hairline cracks that allow water penetration.
• Color changes: Cement grout often darkens or becomes uneven in color over time, especially in areas with hard water.

Best Cement Grout Products for Showers

• Prism (Custom Building Products): A high-performance cement grout with added polymers for better water resistance and color consistency than standard cement grout.
• Mapei Keracolor U/S: A professional-grade cement grout with polymer modification for improved flexibility and stain resistance.
• Polyblend Plus (Custom Building Products): A solid budget option widely available at major home improvement stores.

Grout Color Selection for Showers

Color choice affects both the appearance and the maintenance of your shower grout.

Light Grout (White, Cream, Beige)

Light grout creates a clean, seamless look, especially with white or light-colored tile. However, it shows every stain, mold spot, and discoloration. If you choose light grout in a shower, epoxy or urethane is strongly recommended to maintain the color.

Medium Grout (Gray, Taupe)

Medium tones are the most practical choice for shower grout. They complement most tile colors, hide staining and minor discoloration, and still look clean and intentional. Medium gray is the most popular shower grout color for good reason.

Dark Grout (Charcoal, Black)

Dark grout creates bold contrast with light tiles and hides staining extremely well. However, dark cement grout can sometimes lighten over time due to efflorescence (mineral deposits), creating an uneven appearance. Epoxy grout maintains dark colors much better.

Matching vs Contrasting

Matching grout color to your tile creates a smooth, uniform look that makes the shower feel larger. Contrasting grout highlights the tile pattern and individual tiles. For showers, matching or close-matching grout is generally preferred because it hides any future discoloration along grout lines.

Application Tips for Shower Grout

Regardless of which grout type you choose, these tips will help you achieve a professional result.

• Wait for thin-set to cure: Let your tile adhesive cure for at least 24 hours (48 hours is better) before grouting. Grouting over wet thin-set traps moisture.
• Remove spacers first: Pull out all tile spacers before grouting. Grout over spacers creates weak spots.
• Work in small sections: Especially with epoxy, apply grout to a 3-to-4-square-foot area at a time. Clean the tile surface before moving to the next section.
• Use a grout float at 45 degrees: Hold the float at a 45-degree angle and push grout diagonally across the tile to fill joints completely. Dragging along the joint line can pull grout out.
• Pack joints fully: Press grout firmly into joints to eliminate air pockets. Incompletely filled joints crack and allow water penetration.
• Clean with minimal water: Use a barely damp sponge to clean grout haze from tiles. Excess water weakens cement grout and creates a chalky surface.
• Use silicone at corners and changes of plane: Where walls meet walls, walls meet floors, and tile meets fixtures (showerheads, faucets), use color-matched silicone caulk instead of grout. These joints need flexibility to handle movement.

Maintenance and When to Regrout

Even the best grout needs some attention over time. Here is how to maintain each type and when to consider regrouting.

Regular Maintenance

• Epoxy: Wipe down with a mild cleaner weekly. No special products needed. Epoxy grout stays clean with minimal effort.
• Urethane: Clean with a non-abrasive cleaner. Avoid harsh chemicals and stiff brushes that can damage the surface.
• Cement: Clean regularly with a pH-neutral cleaner. Reseal every 6 to 12 months. Address mold immediately with a diluted bleach solution or oxygen bleach cleaner.

Signs You Need to Regrout

• Grout is crumbling, cracking, or falling out of joints
• Persistent mold that returns within days of cleaning
• Grout has become soft or powdery
• Water is seeping behind tiles (you may notice staining or dampness on the other side of the wall)
• Grout has receded below the tile surface, creating channels where water pools

Regrouting Process

To regrout, use a grout removal tool (oscillating multi-tool with a grout blade works best) to remove old grout to a depth of at least 2/3 of the tile thickness. Vacuum out all dust and debris, then apply new grout following the manufacturer’s instructions. This is a good opportunity to upgrade from cement grout to epoxy or urethane.

Our Recommendation

For most homeowners, here is what we suggest:

• Best overall: Epoxy grout. The upfront cost and difficulty are worth the decades of zero-maintenance, waterproof performance.
• Best for DIYers: Urethane grout. Nearly as good as epoxy in a shower environment but dramatically easier to work with.
• Best on a budget: Sanded cement grout with a high-quality penetrating sealer. Plan to reseal every 6 to 12 months and address stains promptly.

If you are investing in a quality shower tile installation, spending the extra $30 to $60 on epoxy or urethane grout is one of the smartest upgrades you can make. It saves you hours of maintenance and years of frustration with stained, moldy cement grout.