How to Fix Grout That Is Stained (Restore It Without Regrouting)

Stained grout is one of the most frustrating tile problems — it makes an otherwise clean floor look dirty no matter how much you mop. The good news: you don't always need to regrout to fix stained grout. Depending on how deep the staining goes, you can restore your grout to like-new condition with the right cleaner or a grout color pen.

This guide covers both approaches so you can choose the right fix for your situation.

Why Does Grout Get Stained?

• Dirt and grime buildup — grout is porous and absorbs dirt, especially in high-traffic areas
• Mop water — dirty mop water pushed into grout lines is one of the most common causes of grey or brown staining
• Food and drink spills — coffee, wine, and cooking oils can permanently stain unsealed grout
• Hard water — mineral deposits leave white or yellow staining on grout
• Rust — metal furniture legs or pipes can leave orange-brown rust stains
• Mold and mildew — black or green staining in wet areas is usually mold (see our mold guide for this specific issue)

Method 1: Deep Clean the Grout First

Before reaching for a color pen, try a deep clean — many stains that look permanent will come out with the right cleaner and some scrubbing.

What you'll need:

• Black Diamond Ultimate Grout Cleaner
• Stiff grout brush
• Warm water

Step 1: Apply the grout cleaner directly to the stained grout lines. Allow it to sit for 5–10 minutes to penetrate the stain.

Step 2: Scrub firmly with a stiff grout brush, working along the grout line.

Step 3: Rinse thoroughly with clean water and allow to dry completely.

Step 4: Repeat if needed for stubborn stains.

Method 2: Use a Grout Color Pen (Best for Permanent Staining)

If deep cleaning doesn't fully restore the grout color, a grout color pen is the fastest and most effective solution. It coats the grout surface with a new color layer that covers staining and refreshes the look of the entire floor.

What you'll need:

• Grout Renew Pen (White)
• Clean cloth
• Painter's tape (optional)

Step 1: Clean the grout first.
Even if you're using a color pen, clean the grout thoroughly before applying. The pen bonds better to clean grout and the color will be more even.

Step 2: Apply the color pen.
Run the tip of the grout renew pen along the grout line with steady, even pressure. The pen deposits a thin layer of color-matched coating over the grout surface.

Step 3: Wipe excess off tiles immediately.
Use a clean cloth or damp sponge to wipe any color that gets onto the tile surface before it dries. Work one section at a time.

Step 4: Allow to dry.
Let the coating dry for 1–2 hours before foot traffic. Avoid getting it wet for 24 hours.

Method 3: Regrout (For Deeply Stained or Damaged Grout)

If the staining has penetrated deep into the grout and cleaning or color pens don't give satisfactory results, regrouting is the most thorough solution. See our full guide: How to Regrout Tile Floor.

How to Prevent Grout Staining

• Seal grout after installation and annually in high-traffic or wet areas
• Clean spills immediately — the longer a spill sits on unsealed grout, the deeper it penetrates
• Use a clean mop — dirty mop water is a major source of grout staining
• Choose darker grout colors in high-traffic areas — they show staining far less than white or light grey grout

Frequently Asked Questions

Can stained grout be restored without replacing it?
Yes — in most cases, a combination of deep cleaning and a grout color pen can restore stained grout to like-new condition without regrouting.

How long does a grout color pen last?
A grout color pen coating typically lasts 1–3 years depending on traffic and cleaning frequency. It can be reapplied easily when it starts to wear.

What's the best cleaner for stained grout?
An alkaline grout cleaner like Black Diamond Ultimate Grout Cleaner is effective for most organic stains (dirt, food, mop residue). For rust or mineral stains, use a specific rust or hard water remover.

Will bleach fix stained grout?
Bleach can lighten some stains but used repeatedly it degrades grout over time. It's better to use a dedicated grout cleaner for regular stain removal.