Waterproofing behind and underneath Vanity Cabinet in The Bathroom?

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  akyeeeahdude on 13/12/2021 - 19:43

  Waterproofing standards vary slightly from state to state so if you could confirm your state, that would be useful.

  Unless it's changed over the past few years, I'm not aware of any state that mandates behind a vanity is tiled in residential homes. It's generally just a portion above the vanity/sink needs to be tiled.

  • 

    shouchan85 on 13/12/2021 - 20:06

    Thanks, I live in NSW

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  bobbified on 13/12/2021 - 20:26

  I'm in Victoria and when I look underneath the vanity unit (floating, wall mounted as opposed to free-standing), there's nothing. It's all hollow and I can see the beams. That's how the apartment came and the others are the same. There's no waterproofing at all.

  There's no reason the water from the taps should be able to get behind the unit. If the taps leak, it'll be on the floor.

  • 

    AndyC1 on 13/12/2021 - 20:30

    So where does the water pipes go then? Out the front of the unit? If they go out the back of the unit then water can flow down the pipes and into the gap.

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      bobbified on 13/12/2021 - 20:40

      I can actually look down and see where the copper water pipes come out of the "wall". The flexible, braided pipes then screw into the copper pipes. The other end of the flexible pipes attaches to the mixer underneath the sink. There's not much else.

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        AndyC1 on 13/12/2021 - 20:41

        So if the flexible pipes leak and I have seen them leak where will the water go?

        • 

          bobbified on 13/12/2021 - 20:44

          @AndyC1: If there's a leak at the join between the copper pipes and the flexible hoses, it'll leak on the floor (the copper pipes stick out a few centimetres from the wall). If there's a leak where the hose joins the mixer, it'll probably run down the hose and land on the floor too.

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  AndyC1 on 13/12/2021 - 20:28

  +3

  Bunnings sell a 4L waterpoofing paint for $72.30 and they have a 1L for $24.80:

  https://www.bunnings.com.au/crommelin-4l-shower-waterproofin…

  I would buy it and DIY then once it's done tile over it. Allot cheaper than the $850.

  I would waterproof anything in a bathroom you can as water can seep into anything and cause paint to peel on the other side of the wall or cause other issues. For peice of mind the $72.30 it is cheap and it not take too long to do as it's only a small area.

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    shouchan85 on 14/12/2021 - 08:42

    Thanks thats good suggestion!

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  akyeeeahdude on 13/12/2021 - 22:28

  Hmm - remember when you install a vanity, you silicon the gaps where the vanity sits against the wall. No water is getting through this - there's absolutely no need to waterproof or tile behind your vanity for this reason. You could if you want though - your wallet will just be lighter.

  • 

    shouchan85 on 14/12/2021 - 08:45

    Thanks, I thought so too but thought may be wrong, thanks for the confidence boost

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  weezlebub on 14/12/2021 - 11:22

  waterproofing is easy, just paint it on … yourself, straight onto the concrete or whatever's underneath …

  it's not going to do much anyway, it's meant to be a layer, so unless you want to remove all of the tiles and start fresh, you should probably just tile it and forget you never saw it

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  shouchan85 on 16/12/2021 - 11:34

  Thanks all for sharing your knowledge. I'm surprised by the quick response from everyone and how active the community is. Much appreciated.