Spetz Specs No. 4474: step-by-step surface & covering guide

Tile Grout Refinishing: Cleaning, Painting, and Sealing

The complete step-by-step guide made from Kathartic Studios's YouTube video, free on Spetz. For the video, a step-by-step player and answers to your questions, see the Tile Grout Refinishing: Cleaning, Painting, and Sealing project page.

4 steps, 9 tools, 4 materials

Overview

Finished size: Main floor mudroom, kitchen, and dining room

The surface and covering

• Restore stained sand-and-cement floor grout between smooth printed tiles.
• Deep-clean joints, brush on two coats of grout colorant, and seal.
• Colorant locks in an even shade, hiding permanent dark stains.

Why do it yourself

• Squeeze-bottle colorant and a toothbrush replace messy grout removal.
• Dried sections blend without a wet edge for short work sessions.
• Excess colorant shears off smooth tiles with a rubber caulking tool.

What it takes

• Plan on multi-day, hands-and-knees scrubbing, brushing, and scraping.
• Let rinse water dry several hours; wait 24 hours before scraping.
• Wear a respirator and open windows when spraying aerosol topcoat.

What decides success

• Strip grease and cleaner residue so colorant bonds to bare grout.
• Brush on thin, even coats; keep colorant off porous or textured tiles.

Layout at a glance

• Laid on: 30-year-old sand and cement grout between large-format smooth printed tiles
• Start: Test the colorant in an inconspicuous spot first, then work in small sections across the floor; a wet edge is not required between sessions
• Bond: Two thin coats of grout colorant squeezed from the bottle nozzle and brushed into deep-cleaned grout lines with a toothbrush, cured 24 hours, and finished with one coat of spray-on grout sealer.
• Baseboards: Mask baseboards with painter's tape before applying grout colorant, as dried colorant is harder to remove from trim than from smooth tile.
• Smooth tile edges along grout lines: Let the colorant dry for at least 24 hours, then pull a rubber caulking tool along both sides of the grout line to cleanly shear and flake excess paint off the tile.
• Textured slate-like transition tiles between rooms: Keep colorant strictly inside the grout joint or mask tile edges with painter's tape; if overpaint occurs, scrub the tile with soapy water and touch up the grout line.
• Tile chips and cracks: Dab matching grout colorant directly into small chips or cracks on the tile surface to conceal damage.

Health and safety

Bleach Cleaner Handling

• Wear rubber gloves and eye protection when applying and scrubbing the clinging bleach gel to prevent chemical burns and splashes.
• Never mix the bleach toilet bowl cleaner with ammonia or acid products, as this releases toxic gas.
• Scrub carefully with the brush and toothbrush so bleach gel does not splatter onto your skin or eyes.

Aerosol Sealer and Fumes

• Wear a respirator when applying the 511 spray-on aerosol grout sealer so you never inhale strong fumes.
• Open windows and doors to establish cross-ventilation before applying the bleach cleaner or spraying the aerosol sealer.
• Keep the aerosol grout sealer away from open flames and heat sources during application and storage.

Safe Cleanup and Wet Floors

• Never rinse chemical-soaked cloths, scrub brushes, or buckets in a kitchen sink to prevent food contamination.
• Step carefully on wet tiles while rinsing bleach gel and mopping with water to avoid slipping.
• Wash your hands thoroughly with water after removing your rubber gloves and handling the grout colorant.

The surface & its prep

• Substrate: 30-year-old porous sand-and-cement grout between smooth printed tiles.
• Deep-clean grout lines and rinse twice with clean water to remove all bleach.
• Let cleaned grout dry several hours until trapped moisture evaporates.
• Test colorant on a hidden grout line first; bottle labels do not match dried color.
• Mask baseboards and porous slate transition tiles with tape before applying colorant.

Tools

• Scrub Brush
• Bucket (optional)
• Cloth
• Toothbrush
• Caulking Tool (Rubber scraper)
• Broom and Dustpan (optional)
• Flat Mop (Swiffer-style, Swiffer) (optional)
• Respirator (optional)
• Gloves (Rubber)

Materials

• Toilet Bowl Cleaner (Clinging Bleach Gel, Clorox)
• Grout Refresh Colorant and Sealer (Grout Refresh, Mapei, Straw)
• Spray-On Grout Sealer (Aerosol, Miracle Sealants, 511)
• Water

Finishes & supplies, in the order they go on

Before you start

Protect and clear

• Clear furniture and rugs from mudroom, kitchen, and dining floors.
• Vacuum or sweep loose grit from grout joints.
• Mask baseboards and textured transition tiles along grout edges.

Tool set-up

• Fill a bucket with clean rinse water; keep it out of the kitchen sink.
• Get a stiff scrub brush, cloths, old toothbrush, and rubber caulking tool.
• Test grout colorant in a hidden corner to check the dried shade.

Step by step

Step 1: Deep Clean the Grout

Grout joints are deep-cleaned, rinsed free of chemical residue, and dry.

Watch this step (0:46)

You'll need: Scrub Brush, Bucket, Cloth, Gloves, Toilet Bowl Cleaner, Water

1. 1.1 Apply Cleaner and Wait
   • Wear rubber gloves before opening the toilet bowl cleaner.
   • Squeeze a continuous bead of clinging bleach gel along each grout line.
   • Let gel sit 1 to 3 hours to break down embedded stains.
2. 1.2 Scrub the Grout Lines
   • Run a stiff scrub brush back and forth along each grout joint.
   • Scrub dark patches until loosened grime lifts into the gel.
3. 1.3 Wipe and Rinse the Floor
   • Wipe up dirty gel with a damp cloth, wringing it into a bucket.
   • Change bucket water every 10 sq ft so you do not spread residue.
   • Mop again with plain water to remove bleach.
   • Wait several hours until porous grout dries completely before painting.

Key measurements

• Cleaner dwell time on heavy stains: 1 to 3 hours
• Change rinse water: every 10 sq ft of floor

• Tip: Clean large floors in daily sections, not all at once.
• Tip: Use a steam cleaner, dedicated grout cleaner, or peroxide and baking soda if preferred.
• Heads up: Harsh toilet bowl cleaner wears cement grout over time: use it once for prep and never leave it on longer than 3 hours.
• Heads up: Avoid dyed toilet bowl cleaners; they stain light grout.
• Heads up: Never rinse chemical-soaked cloths in a kitchen sink.

Before you move on: Feel several lines: grout must be bone dry with no soapy or slick bleach residue.

Step 2: Paint the Grout

Two thin, opaque grout colorant coats cover every joint and surface chip.

Watch this step (3:13)

You'll need: Toothbrush, Grout Refresh Colorant and Sealer

1. 2.1 Apply Paint to Grout Lines
   • Shake the bottle; squeeze a narrow colorant bead onto the grout line.
   • Apply sparingly; a small bead stretches far.
2. 2.2 Spread Paint with a Toothbrush
   • Work the bead into the joint with short toothbrush strokes.
   • Spread a thin layer that fills every pinhole without pooling.
   • Dab colorant on small tile chips or cracks to hide damage.
   • Stop and restart anywhere; dried edges blend seamlessly.
3. 2.3 Apply a Second Coat
   • Check the dry first coat for translucent spots or dark bleed-through.
   • Squeeze and brush on a second thin coat for solid opacity.
   • Cure the final coat at least 24 hours before scraping smooth tiles.

Key measurements

• Colorant coats: 2 thin coats for full opacity
• Cure time before dry scraping: at least 24 hours
• Textured-tile working time: wipe excess within 20 to 30 minutes

• Tip: Use an angled chisel-point brush instead of a toothbrush on narrow lines.
• Tip: Try Haystack or Driftwood if Straw dries lighter than your tile.
• Heads up: Do not cure colorant 24 hours on slate or textured tile, or it locks into the pores.

Before you move on: After the second coat dries, check for uniform, opaque color with no bare grey patches.

Step 3: Scrape Excess Paint

Overpaint is sheared clean from tile faces, leaving crisp grout lines.

Watch this step (5:30)

You'll need: Caulking Tool, Broom and Dustpan, Scrub Brush, Grout Refresh Colorant and Sealer, Water

1. 3.1 Scrape Paint from Tiles
   • Wait at least 24 hours until the colorant cures.
   • Press a rubber caulking tool edge against the tile beside the joint.
   • Pull the tool along both sides of the line to shear off overpaint.
   • Scrub textured transition tiles with soapy water and a brush if overpaint stuck.
   • Fingertip-dab fresh colorant onto joints where paint lifted.
2. 3.2 Clean Up Paint Flakes
   • Sweep up dried paint flakes with a broom and dustpan.
   • Check every intersection and scrape off remaining paint specks.

Key measurements

• Dry time before scraping smooth tile: minimum 24 hours

• Tip: On textured non-glass tile, wipe overpaint after 20 to 30 minutes with a damp sponge and diagonal 80-grit sanded sponge strokes, then buff with microfiber.
• Heads up: Scrubbing textured tile after paint cures can peel colorant from the joint.

Before you move on: Run a finger along the tile edges to verify no dried paint ridges remain on the tile surface and no bare spots show in the grout.

Step 4: Seal the Floor

An even, puddle-free protective sealer coat covers the refinished grout.

Watch this step (8:11)

You'll need: Flat Mop, Respirator, Spray-On Grout Sealer

1. 4.1 Spray the Sealer
   • Open windows; wear a respirator before spraying.
   • Hold the aerosol sealer can 6 inches above the floor.
   • Sweep narrow fan spray along grout lines in small sections.
2. 4.2 Spread the Sealer Evenly
   • Run a clean, dry flat mop over it immediately.
   • Buff excess off tile faces, leaving sealer in recessed joints.
   • Let the floor dry undisturbed for at least 1 hour.

Key measurements

• Spray distance: 6 inches above the floor
• Sealer dry time: at least 1 hour before foot traffic

• Tip: Skip if desired; the grout colorant has a built-in sealer.
• Heads up: Never inhale aerosol sealer fumes: cross-ventilate and wear a respirator.
• Heads up: Wipe excess aerosol sealer off painted grout immediately so it does not cure into a sticky surface residue.

Before you move on: Under angled light, check tile faces have no puddles or hazy sealer streaks.

Finishing

Touch-ups and trim

• Peel painter's tape off baseboards and transition strips after scraping.
• Scrape stray colorant drops off baseboards before they harden.

Cure and traffic

• Keep pets and foot traffic off the floor at least 1 hour after sealing.

Care

• Vacuum tile regularly instead of wet-mopping with harsh chemicals.
• Spot-clean spills with a damp grout sponge and cold water, then towel dry.
• Mist hard-surface cleaner on a microfiber pad instead of flooding the floor.

Alternatives

• Leave low-traffic floors unsealed, relying on the colorant's built-in sealer.
• Wipe smooth tiles with paper towels as you paint to skip dry scraping.

Check before you call it done

These Specs are built from Kathartic Studios's video “Tile Grout Refinishing: Cleaning, Painting, and Sealing”. Open the Tile Grout Refinishing: Cleaning, Painting, and Sealing project page.