Regrouting to Prevent Mould in The Bathroom and Kitchen Sink

• 

  brendanm on 29/03/2023 - 14:39

  I've just done white epoxy grout for the shower floor in one of my bathrooms. It was a horrible job. Meant to be much better than standard grout though, haven't had it long enough to report on yellowing, though if it does, I imagine it would have to have a lot of direct sunlight.

• 

  JimB on 29/03/2023 - 14:51

  -1

  What have you tried so far?

  What about scrubbing clean, then bleaching it with thick domestos type bleach. And they soaking it in vinegar for good measure.

  • 

    jjjaar on 29/03/2023 - 15:33

    +1

    Bleach and vinegar are not good for grout as they weaken it, causing it to erode. This can result in water getting into the eroded areas and under tiles, making it more susceptible to growing mould.

    It’s likely that use of bleach (even those marketed for bathrooms and kitchens) is part of the cause for this in the first place.

  • 

    Starlight8 on 29/03/2023 - 16:06

    My grout acutally doesnt have many problems but its the silicone applied near the kitchen sink, bathtub area and bathroom sink where mould has appeared.

    I've tried vinegar, 30 second shower cleaner and selleys mould remover :(

    • 

      jjjaar on 30/03/2023 - 00:54

      Silicone will get mould every 2-5 years, depending on how well ventilated the room is (/how humid it is) and how meticulous you are at wiping it down so water doesn’t pool. It’s not uncommon. Just remove and re-silicone it.

      • 

        Starlight8 on 30/03/2023 - 14:44

        Oh wow, i didnt know mould grows on grout - yup definitely been 5 years if not longer!

        Would you by chance know if mould resistant silicone work? Selleys 290ml No Mould Resistant Silicone Sealant ?

        I was thinking an easy fix was to replace it with epoxy grout.

        • 

          jjjaar on 30/03/2023 - 14:50

          @Starlight8: Anything that claims it is mould resistant will likely have specific caveats like “wipe dry after every shower”, or something that’s just never gonna happen.

          I’m sure it’ll work just as fine as the other ones, but will still likely need to be replaced again in 2-5 years.

          Just make sure whatever you use, you follow the instructions and let it cure properly before using the space again (sometimes up to 48 hours).

          I’ve not worked with epoxy grout, so can’t comment on it at all let alone in comparison to silicone. Hopefully some others can provide help.

• 

  redforever on 29/03/2023 - 15:20

  Have you tried grout pen?

  • 

    Starlight8 on 30/03/2023 - 14:56

    Hi, thanks for your suggestion - i wasnt actually clear about the problem.

    Mould is growing on the silicone near my bathtub, kitchen sink and bathroom sink - thinking of fixing the problem by replacing whole bathroom by epoxy grout.

• 

  cashless on 29/03/2023 - 15:51

  -1

  anyone can shred some light

  Probably not a good idea to shred lights in the bathroom

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  sam-1966 on 29/03/2023 - 16:12

  +1

  Shannon Lush (used to be on ABC radio) recommends oil of cloves for mould and says it is the only thing that will actually kill the spores. You might be able to find the instructions on line.

  I remember that after the 2011 floods in Brisbane, it was almost impossible to buy - sold out everywhere.

  • 

    MS Paint on 29/03/2023 - 16:25

    She is the rudest radio guest I've ever heard. She acts like some sort of cleaning goddess and everyone elseis as thick as bricks. I always changed channels when Shannon Lush came on.

    • 

      sam-1966 on 29/03/2023 - 17:41

      But she had some great ideas! My kids would bitten by insects at school everyday - then I tried her suggestion of lavender oil and water in a spray bottle. Sprayed them head to foot every morning, no more bites.

      And her suggestion re bleeding noses - get a teabag (ordinary black tea), dampen it and sniff - brilliant.

      She could be kind of kooky, I agree - but loved her ideas.

  • 

    Starlight8 on 02/04/2023 - 23:01

    +1

    Thanks for the tip :)

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  Bargainitis on 29/03/2023 - 16:57

  -1

  If your existing grout has darkened or have some mold, toilet bleach does wonders. Generously pour it on the grout and leave it for a 30 mins - most stains will come out.

  Otherwise, regrouting (not re-siliconing though your post talks about both?) is messy work. You will need to remove the existing grout (I have used a high speed disc to grind it out). Inserting fresh grout is not difficult though.

  • 

    jjjaar on 30/03/2023 - 00:58

    No to any form of bleach, it is not an actual fix. It simply makes it look like it’s gone, but it comes back quicker and worse

• 

  ChocStrawberries on 29/03/2023 - 17:08

  -1

  Try soaking paper towels in vinegar and leaving on the problem areas overnight. If that doesn't work, try a mould remover spray (lots of it) or bleach instead of the vinegar. A friend swore by this when doing an end of lease clean recently. YMMV.

  ETA - it was the paper towels that did the trick, something about it not being able to dry out as quickly.

  • 

    jjjaar on 30/03/2023 - 00:56

    -2

    A friend swore by this when doing an end of lease clean recently

    I’m sure the new owners would have loved that.

    Bleach or vinegar only seemingly remove it, but actually degrade the grout and make mould more likely to come back quicker.

    • 

      ChocStrawberries on 30/03/2023 - 10:56

      -1

      The OP was talking about silicone, which is what I was referring to.

      • 

        jjjaar on 30/03/2023 - 14:46

        -1

        Bleaching silicone has the same effect, it can compromise the structure, or erode it completely. Silicone is not just used to make things look pretty, but rather prevent water from pooling in corners, so to erode the silicone with bleach, the water pools and mould grows in/on and underneath.

        • 

          Starlight8 on 02/04/2023 - 23:00

          @jjjaar: Thanks for the reply and advice.

          It seems like the consensus is to now remove the silicone and replace it :)

          I just need to find a tradie who can do this for me now :)

          • 

            jjjaar on 03/04/2023 - 09:37

            @Starlight8: How much is there to do? It’s relatively easy to do yourself. You just need a caulking gun and the right silicone.

• 

  jizmo on 29/03/2023 - 18:07

  Grab one of these little suckers.

  • 

    Starlight8 on 02/04/2023 - 22:58

    Thanks for the tip, I will definitely get one once i get it all resolve - for future cleaning :)

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  Transient on 29/03/2023 - 19:13

  1. I think so. Replaced shower grout with epoxy grout. Still can go mouldy but easier IMO to remove mould and did not stain unlike cement grout.
  2. Don't buy the white Dunlop epoxy grout from Bunnings. Not white to begin with. Fixed it with grout pen. Touch up every one to two years
  3. I think easier to clean. With cement grout the grout was stained dark grey after mould removal with exit mould. Could never get it white. Epoxy grout still can go mouldy but the mould does not stain the grout as non porous.
  4. I did it myself. Harder to apply and remove than cement grout but I think worth it. You need to make sure you get white grout, eg MAPI. Applied it >5 years ago. Only need to clean the shower once a month. Used a sandy beige colour for the floor tiles and it looks good.
  • 

    Starlight8 on 02/04/2023 - 22:57

    Thanks so much for the indepth reply, i much appreciate it :)

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  Euphemistic on 30/03/2023 - 08:37

  So it’s not really the grout?

  Sounds like you need to remove the silicone, clean the mould then reapply the silicone. Leave the grout alone if it isn’t mouldy.

  • 

    Starlight8 on 30/03/2023 - 14:42

    Hi there,

    Thanks for the reply.

    Sorry i probably should've explained that the wet areas in my bathroom (ie. sink, bath tub and kitchen sink) have been filled with silicone and mould has grown on it and i cant get it out.

    I was thinking perhaps epoxy grout would fix the problem?

    • 

      Euphemistic on 30/03/2023 - 15:52

      Silicone is usually in areas where you need flexibility due to movement in joints.

      • 

        Starlight8 on 02/04/2023 - 22:56

        Thanks for the reply, if i cant DIY - who can I hire do this?

• 

  wobblydrow on 03/04/2023 - 16:04

  +1

  HI

  I used to be technical manager for the largest silicone supplier in the market. The reason silicone goes mouldy is not the silicone itself, but soap scum and other build up that mould can grow on, which then can penetrate the silicone (or grout surface). The epoxy grouts are good as the hardness and strength resist the mould penetration better, however, as mentioned they are more difficult to apply and make more mess. i would not do an epoxy job without some experience as the material has a pot life and once it starts to cure its difficult to correct errors.

  Cement grouts are fine where areas wont move, such as between fully bonded tiles, but for areas subject to movement stress, such as a vertical surface meeting a horizontal one, a silicone is better as they have a minimum 25% movement capability, so will take up deformation, whereas cement will crack. Epoxy grouts tend not to crack, but are so strong can rip off one side of a joint and allowing water to penetrate….so the moral is understand the products and where each should be used

  • 

    Public21 on 04/04/2023 - 09:57

    So if you spray on something that gets rid of soap scum, will that help? Or- will it also damage the silicone?

  • 

    Starlight8 on 13/04/2023 - 16:55

    Hi there,
    Thanks for your suggestion,
    Yup i think i have learnt that where there is silcone, i will just get it replaced.
    May I ask if you have a suggestion on which silicone is most mould resistant? Thanks!