How to Clean Grout: Why Vinegar Can Damage It

The short answer from the Tile Council of North America (TCNA): clean cement-based grout with an alkaline or tile-and-grout cleaner rather than an acid, rinse it well, and consider sealing it. Acids, including vinegar, attack the cement that holds grout together. This guide covers the steps, mould, sealing, and what to do when grout still will not come clean.

We sell the Eco All Purpose Spray and the Eco Bathroom Cleaner, so read the product notes with that in mind. Where a point comes from our product pages rather than TCNA or Health Canada, the guide says so. Our bathroom cleaning guide covers the rest of the room.

What Should You Know Before You Clean Grout?

Know what your grout is made of. The Tile Council of North America says cementitious grout is based mainly on cement and sand, is porous, and can absorb a stain.

• Cement grout is porous: TCNA says that under a microscope it has a large surface area that can take up stains, which is why many owners seal it.
• Cement reacts with acids: Sand is unaffected by most cleaners, but TCNA says cement is alkaline and is dissolved by acids.
• Epoxy grout is different: TCNA says epoxy grout is virtually as stain-proof as the tile. Its guidance on this page is for cement grout, so check the maker's instructions if yours is epoxy.
• Check the tile too: Natural stone has its own limits. The Natural Stone Institute says products with lemon, vinegar or other acids may dull or etch calcareous stone.

Is Vinegar Safe to Use on Grout?

Generally not on cement grout. TCNA says grout and vinegar react the way baking soda and vinegar do, and that it is better to clean grout with an alkaline cleaner than an acid-based one.

• Why acid still comes up: TCNA says some installers remove very stubborn stains by dissolving the top layer of grout. Grout manufacturers do not recommend it, and TCNA says regrouting is sometimes the result.
• Never mix it with bleach: Health Canada's bleach alert says bleach reacts with any cleaner containing ammonia or an acid, including vinegar, and can release toxic gases.
• Our acid-based cleaner: The Eco Bathroom Cleaner uses citric and lactic acid. Given TCNA's advice, we do not suggest it on cement grout lines, and we found no test of it on grout.

How Do You Clean Grout Step by Step?

Apply a suitable cleaner, scrub, then lift the dirty water and rinse. Step 1 follows Health Canada; steps 2, 4 and 5 follow TCNA; steps 3 and 6 are general practice, not a cited standard.

1. Ventilate and glove up. Open a window or run the fan and wear gloves. Health Canada's household chemical safety page says to follow the label and ventilate during and after use.
2. Pick the right cleaner. TCNA names alkaline household cleaners, specialty tile-and-grout cleaners and enzyme cleaners, and says to avoid oil- or wax-based cleaners, which leave a film in the grout. It adds that tile itself can often be cleaned with water.
3. Apply and scrub. Apply the cleaner to the joints and work it in with a soft brush, following the label for how long to leave it. A soft brush is general practice.
4. Vacuum up the dirty water. TCNA calls this the absolute best way to clean grout: after applying the cleaner, vacuum up the dirty water with a shop vac to lift the dirt off the joint.
5. Rinse and vacuum again. TCNA says even good alkaline cleaners leave a sticky soap film if they are not rinsed properly, and that film tends to attract dirt. Apply rinse water and vacuum it up.
6. Let it dry. Leave the area ventilated until the grout is dry. That is general practice.

Can You Use Eco All Purpose Spray on Grout?

Our product page does not mention grout, and we have not tested it on grout. What we can say is what the page lists, so you can compare it with TCNA's advice.

• Ingredients: The page lists seven named ingredients, including sodium carbonate and sodium hydroxide, which are alkaline, plus a chelating agent and surfactants. It is sold unscented.
• Stated surfaces: The page names plastics, ceramics, painted walls, sealed countertops, glass, stainless and general hard surfaces.
• Test first: Try it on a hidden joint, then rinse and vacuum as in steps 4 and 5, since TCNA warns that unrinsed alkaline cleaners leave a sticky film.
• A specialty product is a fair choice: TCNA says specialty tile-and-grout cleaners exist for exactly this job. If you prefer one, follow its label.

How Do You Clean Mould or Mildew From Grout?

For a small or medium area, Health Canada's mould page says you can generally clean it yourself with water and dish detergent, and that there is no need to use bleach.

• Protect yourself: It says to wear safety glasses or goggles, a disposable N95 respirator and household disposable gloves.
• Know the size: It calls 1 to 3 patches, each under 1 square metre, small, and more than 3 patches or patches up to 3 square metres medium. Above 3 square metres is extensive.
• When to call someone: It advises considering a professional for extensive mould, or if the mould keeps coming back after you clean it.
• Fix the cause: It says to fix the underlying cause, such as water damage, too much humidity or not enough ventilation, and to keep humidity between 30% and 50%.

Should You Seal Grout?

For cement grout, TCNA says sealer is generally a very good idea. Epoxy grout is not the cement grout it is talking about.

• Two kinds of sealer: TCNA says penetrating sealers bond with the grout and repel water and water-based stains, while topical sealers coat the surface and repel almost everything until foot traffic wears them off.
• Cost and look: It says topical sealers are generally less expensive but give grout a plastic appearance, while penetrating sealers cost more and are more durable.
• Follow the tile maker: For unglazed tile, TCNA says sealers are generally recommended, but to follow the tile manufacturer's recommendations.

What if Grout Still Won't Come Clean?

TCNA lists steam first, then regrouting as a last resort. A white powdery film is a different problem, and TCNA covers it separately.

• Try steam: TCNA says some stains that do not respond to conventional cleaners come clean with pressurized steam.
• Regrout last: It says some installers cut out the grout and regrout, with care not to damage or loosen the tile, and that new grout generally cannot go directly over old grout.
• The white film: TCNA says this efflorescence is generally removed with acid, but that grout manufacturers do not advocate acids because they attack the cement. It can only return if moisture is getting in.
• Ask a pro: Because acids call for extreme care, a tile retailer or installer can advise on the product for your grout and tile.

Frequently Asked Questions

Can I clean grout with vinegar and baking soda?

TCNA says grout reacts with vinegar the way baking soda does, because cement is dissolved by acids, and that an alkaline cleaner is the better choice.

Can I use bleach on grout?

Health Canada says bleach is not needed for small or medium mould patches, and never to mix it with ammonia or acids such as vinegar, because the mixtures can produce toxic gases.

What is the best way to clean grout?

TCNA says to apply the cleaner, vacuum up the dirty water with a shop vac, apply rinse water and vacuum that up too, which lifts dirt and soap film off the joint.

Should I seal my grout?

TCNA says sealer is generally a very good idea for cement grout, not epoxy. Penetrating sealers cost more but are more durable; topical ones are cheaper but look plastic.

Is Eco All Purpose Spray made for grout?

Its product page does not mention grout and we have not tested it there. Try a hidden joint first, rinse well and vacuum up the water, as TCNA advises for any cleaner.

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