Asked on Jul 31, 2019

How can I replace missing grout on tile kitchen counters?

Valaria Seamans
by Valaria Seamans

I have moved into an older home with beautiful tile kitchen counter tops and back spashes. Some areas of the grout look almost black due to no grout. Some of the grout has worn out over the years. How can I replace these spots where grout is missing without a complete make over, and little fumes.

  5 answers
  • You may need to re-grout the entire counter depending on the color, but they do sell premixed grout, here's my affiliate link.


    https://homedepot.sjv.io/JAJX2

  • Lifestyles Homes Lifestyles Homes on Jul 31, 2019

    As you’ve observed, that is mold in the grout.

    Now is the time to address this, as it is bad for your health and bad for what’s left of your grout.

    If you patch in new grout (water-based formula, no fumes) then the mold spores will grow in the brand new grout 🙄


    Adding new grout is easy and you’ll need a non-sanded latex or acrylic additive grout. It’s powdered & mix it up like pancake mix. More on that later...


    To treat this moldy grout situation first you’ll need to kill and bleach the mold with a food-Grade hydrogen peroxide. It can be bought at health food stores.


    Caution! At 7-15% strength (it depends on where you buy it, as to the strength) it will be caustic. So you must wear long rubber gloves when working with this product, old long sleeved shirt and rinse off the outside of the closed bottle, before putting it in the fridge.


    In a 2-cup Pyrex glass, dilute the hydrogen peroxide to a 7% strength with distilled water. Paint it over all the grout with a dollar store 1” chip brush.

    Let it bubble away for 30 minutes. When you take off your gloves, rinse the gloves a lot first & wipe off the faucet handle with a paper towel. You can’t see the hydrogen peroxide residue.


    After 30 minutes, put the gloves back on, take clean t-shirt rags & mop up the hydrogen peroxide. Throw away the rags. Q-tip the cracks in the counter top, gloves on.


    If the black mold is still black and not lightened, then look and see if there’s old grout sealer or grease build up. Take a nylon scrub pad and scrub the black grout, gloves on, with a clear detergent, rinse & dry w/ clean rags or paper towels.

    Apply more hydrogen peroxide mix, gloves on.


    While waiting that next 30 minutes, check for loose tiles & get out the shop vac. With a small screwdriver or ice pick, pop out the loose grout, wear eye protection and those rinsed off gloves.


    When all grout crumbs are vac’d up, it’s tome to wipe down the counter with clean water & more clean rags. This is assuming the mold is dead & bleached. Throw away the rags.


    Make sure the bottle of peroxide is rinsed & dried before storing in a cool dark place, like the fridge. If you’ve kids, put a big red X on it, and tell them not to touch it.


    Finally grout time! Yay. Mix up the grout in small batches in a plastic container, use a plastic spatula, blob it over the cracks and smoosh it in the cracks and smooth it with the spatula. Do a small section at a time.

    Clean it off the tile faces, as you go. Clean up the joints as you go- you’ll need a big bucket of very mild soapy water & 2 types of old sponges & dry rags.

    Make sure no bubbles are stuck in there. Might get out that tiny clean screwdriver again.

    As the grout dries, it will form a haze on the tiles that weren’t cleaned well enough & that’s a warning sign to get that off of here now.

    Let it dry for 6 hours or overnight & check on it, to make sure no more haze has shown up.

    Getting grout off of tile faces can be difficult if left too long.


    I recommended a penetrating non-yellowing grout sealer, after it has cured 48 hours.

    FYI,

    Tile countertops are not considered “sanitary” by the Health Codes for all restaurants because of the grout and therefore not allowed in their food prep areas.

    Therefore, seal the grout & re-seal it, annually.


  • Be sure to grind out/remove the old grout first as new won’t stick to old. Be sure to use a grout sealer when you’re done too.

  • Kmdreamer Kmdreamer on Aug 05, 2019

    Get the same color grout and mix some then put in cracks with a sponge push in bast you could let dry 35 min then wipe away but don’t wipe grout were you added