How to Replace Grout Around a Tub
Learn to replace grout around a tub with practical steps, tools, and safety tips from Grout Maintenance. This guide covers prep, removal, mixing, application, curing, sealing, and maintenance for durable, mildew-resistant grout.
Goal: replace grout around tub to restore water resistance, prevent mold, and refresh the look. You’ll assess damage, gather the right tools, remove old grout, mix and apply new grout, and allow curing before sealing. The guide covers cementitious vs epoxy options, color matching, and ongoing maintenance. Plan for several hours of work plus drying time and proper ventilation.
Why replacing grout around tub matters
Water exposure is constant around tubs. Over time, grout can crack, crumble, or lose its seal, allowing water to wick behind tiles and promote mold growth. Replacing grout around tub helps restore a watertight barrier and keeps your bathroom looking fresh. According to Grout Maintenance, a proactive grout replacement not only improves appearance but also reduces long-term maintenance costs by preventing damage that might require costly tile repairs later. When grout remains intact, it resists staining and simplifies cleaning, creating a hygienic surface for daily use. In addition, selecting the right grout type and color can help blend with existing tile and extend the life of your installation. The key is to plan for proper curing and sealing, especially in high-moisture zones such as tub surrounds. Throughout this article, you’ll see practical steps, tool recommendations, and safety tips that help homeowners tackle this task confidently without professional help unless needed.
Assessing grout condition around the tub
Start by visually inspecting the grout lines around the tub. Look for cracks, missing grout, powdery or crumbling texture, and darkened areas that indicate moisture intrusion. If you can pinch or press a section of grout and it flakes away, that area should be replaced. Keep an eye on color changes, which may signal mildew growth beneath the surface. In high-moisture zones, even small defects can escalate into bigger issues over time. If you notice recurrent mold, musty odors, or loose tiles, plan to replace the grout and reseal the area to restore both appearance and function. Document problem spots with photos to guide your material choice and color matching before you start.
Materials and color planning
Choosing the right grout type is foundational for tub surrounds. Cementitious grout offers ease of use and broad color options, but epoxy grout provides superior stain and moisture resistance—often worth the added effort for tub environments. Consider color matching to minimize contrast with your tile, or opt for a slightly lighter shade to help hide any minor imperfections during the finish. Don’t forget grout additives or sealers that improve water resistance. If you’re renewing a shower-tub combo, consider grout color and sealer compatibility with your tile glaze. Grout Maintenance recommends testing a color sample on a spare area to ensure you’re satisfied with shade in both daylight and artificial light. Color-fast options tend to stay truer in damp spaces over time.
Surface preparation and safety
Before you begin, turn off any nearby water control and remove items from the tub edge. Protect surrounding surfaces with painter’s tape and drop cloths to catch debris. Ensure the bathroom is well-ventilated; open a window or run a fan to minimize dust and fumes, especially if you’re using epoxy grout or strong sealers. Put on safety glasses, gloves, and a dust mask to guard against grout dust and sharp tools. Thorough ventilation reduces inhalation risk and helps the area dry more quickly after cleaning. Clear a dedicated workspace with good lighting so you can see the grout lines clearly as you work. A clean, dust-free surface improves adhesive bonding and final appearance.
Removing old grout around tub
Carefully cut and remove the old grout using a grout saw or oscillating tool with a grout-removal blade. Work slowly along each line to avoid chipping tile edges. Remove as much of the old grout as possible, then sweep or vacuum the joints to remove dust and debris. For stubborn areas, re-cut along the line and gently pry out remaining fragments with a putty knife. After grout removal, wipe the tile faces with a damp cloth to capture fine dust, then let the area dry completely. Proper removal is critical for new grout to bond properly and prevent future gaps.
Cleaning and drying the joints
Once the old grout is removed, thoroughly clean the joints and surrounding tile. Use a mild tile cleaner to remove any soap scum or mineral deposits, then rinse and dry with a clean towel. Allow the joints to dry completely; moisture trapped in the pores will impede grout adhesion. If you see lingering moisture after several hours, wait longer before mixing the new grout. A dry, dust-free surface ensures a stronger bond and a smoother finish.
Mixing grout and color matching
Follow the manufacturer’s directions for mixing grout. Whether you choose cementitious or epoxy grout, achieve a consistency similar to peanut butter—neither too stiff nor too runny. If you’re using cementitious grout, you’ll generally mix with clean water; if epoxy, mix two parts with a resin hardener according to the package. Prepare enough grout for a few minutes of work to prevent setting in the bowl. Test color on a small tile edge before full application to ensure the shade matches your tile and looks right in your bathroom lighting. Consistency and color uniformity matter for a professional-looking finish.
Applying grout around tub
Load grout into a rubber grout float and hold it at a 45-degree angle to push it into the joints with even pressure. Work in small sections to keep the grout from skinning over in the joints. Remove excess grout from the tile surface by sliding the float diagonally across the face, then wipe the tiles with a damp sponge to reveal clean joints. Rinse the sponge frequently to avoid gray haze on the tiles. In corner areas, use a corner float or a pointed tool to ensure grout fully fills tight spaces without leaving voids.
Finishing and shaping joints
After initial set, shape the joints with a finger or rounded-edged tool to create a consistent, smooth profile. If you’re using cementitious grout, wipe the joints with a damp cloth to remove surface haze and even out the surface. For epoxy grout, you may need to polish the joints lightly after the product cures to achieve a uniform shine. Allow the grout to cure according to the product instructions; curing times vary, and early water exposure can compromise the final result. Keep the area dry and avoid heavy use during this period.
Sealing and curing considerations
Sealing is typically recommended for cementitious grout around tubs to boost moisture resistance, while epoxy grout commonly doesn’t require sealing. If you seal, apply a penetrating grout sealer after the grout has cured fully, following the manufacturer’s guidance. Ventilation remains important during curing to reduce humidity. Inspect for any gaps or darkened spots during the curing window and repair promptly if needed. Maintain a routine of gentle cleaning with a pH-balanced cleaner to protect the grout and tile.
Troubleshooting common issues
If you notice grout haze on tile faces, wipe with a damp sponge and clean water. If joints crack after sealing, check for under-mowed prep work, insufficient curing time, or movement in the substrate. Uneven color can come from moisture during curing or insufficient mixing; reseal or regrout only as needed. For persistent mold or mildew growth, consider a dedicated grout cleaner or a new epoxy grout solution for maximum moisture resistance. Always follow the product instructions closely to avoid compromising the finish.
Long-term maintenance and inspection
Periodic inspection of tub grout helps catch issues early. Clean with a soft brush and non-abrasive cleaner to prevent surface wear. Reapply sealants as recommended by the grout manufacturer, typically every few years for cementitious grout in bathrooms. Keep humidity levels in check with proper ventilation, and address any leaks promptly to protect the substrate. With proper maintenance, you’ll extend the life of the grout and preserve a clean, water-resistant tub surround.
Tools & Materials
- Grout removal tools (grout saw or oscillating tool with grout-removal blade)(4-6 inch blade; use light pressure near tile edges)
- Putty knife(For prying and scraping stubborn bits)
- Vacuum or stiff brush(Keep joints clean of dust and debris)
- Rubber grout float(Even pressure to pack grout into joints)
- Grout mixing bowl and paddle(Large enough for the batch you’ll use in one session)
- Sponge and clean water(Fresh water for rinsing to avoid haze)
- Tile cleaner or mild detergent(Remove soap scum prior to grouting)
- Safety gear (gloves, goggles, mask)(Protection against dust and chemical exposure)
- Sealer compatible with grout type(Use if recommended for cementitious grout)
- Painter’s tape and drop cloths(Protect surrounding surfaces)
- Measuring cup and mixing paddle(Accurate ratio for cementitious grout; epoxy uses different kit)
Steps
Estimated time: 4-6 hours (excluding curing time)
- 1
Prep and safety
Set up a clean work zone with towels and protective coverings. Turn off nearby water lines and remove items from the tub edge. Ventilate the room and put on safety gear. This prepares you for a safer, cleaner job and reduces cleanup later.
Tip: Lay down a plastic sheet to catch debris and protect adjacent fixtures. - 2
Remove old grout
Gently slice along grout lines with a grout removal tool to detach old grout. Work gradually to avoid tile chipping and keep the joints open for new grout to bond. Vacuum the joint area to remove dust after finishing.
Tip: Take your time near tile edges to prevent damage; steady, controlled movements yield the best results. - 3
Clean and dry
Wipe down the tile faces with a mild cleaner, rinse, and dry thoroughly. Let the area dry completely to maximize adhesion. If moisture is still present after a few hours, wait longer before proceeding.
Tip: Dry joints with a clean microfiber towel to speed up the curing process. - 4
Mix grout and prepare color
Mix grout according to the product instructions to the correct consistency. If using cementitious grout, add water gradually and aim for a peanut-butter texture. Test a color sample on a spare tile edge before full application.
Tip: Only mix what you can use in the working time to avoid waste. - 5
Apply grout
Spread grout over joints with the float, holding at a 45-degree angle. Press firmly to fill the joint completely and remove excess from the tile surface. Work in small sections to maintain consistency across all joints.
Tip: Keep grout lines straight and uniform; consistent pressure yields even results. - 6
Finish and wipe haze
Once the grout begins to stiffen, wipe the tile faces with a damp sponge to remove surface haze. Rinse and refill water as needed to avoid dragging color. Let the grout set according to the product instructions before final curing.
Tip: Rinse your sponge often; dirty water can cause hazing on the tile. - 7
Seal and cure
If using cementitious grout, apply a suitable sealer after the grout has cured fully. Follow the manufacturer’s curing times and apply in a well-ventilated space. Avoid water exposure during the initial cure period to prevent staining or weakening.
Tip: Apply sealant in thin, even coats and wipe off excess promptly. - 8
Inspect and maintain
Check joints for gaps and re-seal as needed. Regular cleaning with a pH-balanced cleaner helps prolong color and durability. Keep humidity in check with ventilation to prevent mildew growth.
Tip: Schedule periodic inspections to catch minor issues before they become problems.
Got Questions?
Do I need to remove all old grout before replacing around the tub?
Yes. Removing old grout ensures the new grout bonds properly to clean surfaces and prevents gaps where moisture can hide. Only replace sections with visible damage for efficiency, but complete removal provides the best long-term result.
Yes. Remove all old grout so the new grout bonds to clean surfaces and prevents hidden moisture gaps. You can replace damaged sections if the rest is in good shape.
What is the difference between cementitious grout and epoxy grout for tub surrounds?
Cementitious grout is easier to work with and available in many colors, but it may require sealing in wet areas. Epoxy grout is more resistant to stains and moisture but requires careful mixing and curing. Choose based on moisture exposure and comfort level.
Cementitious grout is simple and colorful but may need sealing. Epoxy grout is tougher against moisture and staining but a bit trickier to work with.
How long does grout cure before sealing?
Cementitious grout typically requires several hours to dry before sealing, but curing can extend for 24-72 hours depending on product and humidity. Always follow the manufacturer's guidelines for your specific grout.
Cementitious grout needs several hours to dry before sealing, but curing can take 1-3 days depending on humidity. Check your product's directions.
Can I replace grout around tub without removing tiles?
In most cases, you can replace grout without removing tiles if the grout is cracked or deteriorated. If tiles are loose or you notice significant substrate damage, you may need professional help and possible tile removal.
Usually you don’t need to remove tiles, but if tiles are loose or the substrate is damaged, you may need professional help.
What safety precautions should I take?
Wear protective glasses, gloves, and a mask for dust and chemical exposure. Ensure good ventilation, and keep children and pets away from the work area. Follow manufacturer instructions for all products to minimize risks.
Wear eye and hand protection, use a mask, and keep the area ventilated. Read product directions for safety tips.
How do I prevent mold after grout replacement?
Choose a grout type with moisture resistance, seal cementitious grout if recommended, and maintain airflow in the bathroom. Clean regularly with a mild cleaner and dry the area after showers to reduce moisture buildup.
Use mold-resistant grout, seal if needed, and keep the space dry and ventilated. Clean regularly and dry the area after use.
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The Essentials
- Assess tub grout condition before starting work.
- Choose the right grout type for moisture exposure.
- Prepare and protect the area to ensure clean results.
- Seal (if needed) after curing for long-term durability.
