How to Fill a Hole in The Ceiling Plaster? (Light Fixtures, Exhaust Vents)

follow on 06/05/2023 - 16:01

I have a few holes in the ceiling I've been putting off repairing.
What product should I use for large (150mm, 200mm) holes?
How about when you cut the hole a little too big? Should you put new plaster in, then cut a new hole?

I've found Spakfilla Heavy Duty, Gyprock Rapid Plaster Repair Kit from Bunnings

From YouTube, I've seen that wood backing is used on behind the new plaster. I plan on reusing that area again so a wood backing will restrict me.

Is there a way to fill large holes without wood backing? Will those products I mentioned to the trick?

Any advice is greatly appreciated.

Home & Garden

Comments

  • AngoraFish on 06/05/2023 - 16:29
    +3

    Cut a square section of plasterboard bigger than the hole. Trace the shape of your precut piece of plaster on the ceiling around the existing hole you want to patch and cut it out. Insert your pre-cut piece into the perfectly sized hole for it. Support the new piece of plasterboard by screwing it to something behind.

    Normally the support piece behind would be timber, as you say, but at a push you could use another longer plasterboard piece in the ceiling to glue to instead of timber, but it will not be as strong.

    Plasterboard jointing tape will help, and you should use it anyway, but the structural benefits will be marginal. Tape will typically not be enough to hold the plasterboard piece in place on its own in the absence of additional support from having the plasterboard piece screwed to something.

    No wet application products will fill a 200mm hole in the ceiling, they'll all drip out even if you try to trowel wet filler through jointing tape

    The plaster repair kit will work, but that's got a sheet of plasterboard in it for the processes above, so doesn't address your issue.

    What are you planning on reusing the area for?

    • follow on 06/05/2023 - 17:02

      My current bathroom exhaust fan is sagging:
      https://ibb.co/Jz8wBMt
      I thought I might patch that area up and move it a little so that it is directly above the shower.
      I wanted to keep that area available in case I don't like the new exhaust fan placement.

      Second one is in my kitchen.
      I installed a new rangehood. The hole for the duct is not completely covered by the flue cover:
      https://ibb.co/s9BZDBP
      https://ibb.co/ssRfTYn
      https://ibb.co/qRWzDyr
      I thought I'd patch that area and move the hole inward

      • dominator293 on 06/05/2023 - 17:19
        +1

        For the excess hole sticking out in the kitchen above the range hood, just use some plaster to fill it. Let it dry and sand it back. You'll never see it and don't need plaster board.

        In regards to the bathroom, just install the new fan and if you like the new location, patch up the old hole properly with some timber backing.

        • fantombloo on 06/05/2023 - 17:42
          +1

          For the excess hole sticking out in the kitchen above the range hood, just use some plaster to fill it. Let it dry and sand it back.

          No way. That ducting is flexible, not designed to be an attractive outer piece. It needs a surround / cover of some sort to hide it. It's an incomplete job.

          • dominator293 on 06/05/2023 - 17:46

            @fantombloo: Did you see the pic of the flue cover that goes all the way to the ceiling? Only a little bit is sticking past the cover so of course you can fill it with plaster.

        • follow on 06/05/2023 - 18:09

          by plaster you mean like spakfilla?

      • AngoraFish on 06/05/2023 - 17:31
        +1

        The sagging is mostly a fan problem, probably one of the brackets has putted through the plaster. Rotating the fan might help. If not, a short metal plate above the plaster in the ceiling at the point of the break might be enough to set the fan bracket on. Looks like this is kind of what someone has tried to achieve with tape previously. Would help to know what's going on in the ceiling.

        If you're making lots of holes that size you're probably better off just buying a full sized Gyprock sheet and fixing it direct to the existing ceiling joists. Make sure the sheet extends well beyond the area you're playing with.

        Before moving the fan make sure that the power cable is lose enough to ensure you can move it around, otherwise you might find yourself having to recable, at which point you may as well just pay an electrician to do it properly. Indeed, can guarantee that moving the fan will be a lot more complicated than it looks. For that stuff, personally, I'd be bringing in an electrician and letting them sort it out. One mistake and you're back where you were with the first fan hole.

        For the duct, I'd just use masking tape around the duct, apply filler to the gap and paint. Having said that, I have exactly the same issue, but care factor is low - it's going to be a fiddly job and you'll have to be careful not to move the duct while filling or you just get a mess.

        • follow on 06/05/2023 - 18:13

          Cheers. Yes, the main issue with bathroom exhaust is the the place where the clip should go chipped off while removing the old one.
          Think I might just go with timber backing and move the exhaust fan to the new area

        • hoey888 on 06/05/2023 - 22:21

          Had very similar bathroom fan issue. Replaced exhaust fan with new one from Bunnings. Had to use old original plastic clips (rotated slightly) as the plaster was damaged.

          If time permits, would probably also paint the bathroom ceiling. Remember to do the prep work before painting (cleaning/disinfecting/sanding).

  • Jimothy Wongingtons on 06/05/2023 - 16:58

    If you mean you’re reusing it again, to put in a smaller downlight you can just use a conversion plate (deta has some), and pretty much every other lighting supplier has some too.

    It covers a big hole but reduces it down to a standard 70 or 90 mm downlight.

    Looks a bit funny but neatest and easiest without messing around with plastering

    SAL and a few others also do larger trim downlights that can be knocked down in output as required without a dimmer , to fill in large cutout traditional downlights

    • follow on 06/05/2023 - 18:06

      tried to find 200mm ones but can't seem to

  • bmxr on 06/05/2023 - 17:38
    +1

    Cornice cement can also help for patching areas that may not have a support to screw new plasterboard in to. We've used it to patch a 100mm x 50mm area around our new bathroom exhaust fan. Just some cardboard to serve as a bit of a backing to the roof void, slather it on with a plaster knife, let it dry, sand it flat and paint to match.

    • follow on 06/05/2023 - 18:06

      does it not sag or look off at all?

      • bmxr on 06/05/2023 - 18:06
        +2

        It's a sticky cement that dries to be almost identical to a sheet of plasterboard

  • MS Paint on 06/05/2023 - 17:41
    +1

    Looks like the shower exhaust fan isn't doing its job with all that mould on your ceiling. Check the supporting clips first as suggested above. Maybe upgrade to a more powerful unit.

    You can get flue extension covers to hide the ugly flue in your kitchen. Most decent rangehoods come with an extendable cover. Look up your manufacturers website to see if they sell extensions. It would look a whole lot better.

    • follow on 06/05/2023 - 17:55

      That was due from a decade of not having a working exhaust fan. 😂
      The mould stopped I was thinking of painting over it but might need to Google if it's safe to do so or if it needs to be "treated".
      Put this one in recently and did a terrible job removing the old one which lead me to this issue.

      Is the flue ugly? I thought it looked standard?
      It does extend to the ceiling but I'm having the issue of the hole for the duct sticks further than the flue cover

      • MS Paint on 06/05/2023 - 18:19
        +1

        This makes more sense now. Cheers.

        I wouldn't bother with the gap around the flue and just trim the plaster to all allow you to just extend the flue cover to the ceiling for aesthetics.

      • bmerigan on 06/05/2023 - 22:02
        +1

        There's an undercoat paint you can get at Bunnings that can cover and seal the mould stains.

  • follow on 06/05/2023 - 18:18

    Thanks everyone.

    For the bathroom, I think it might be easier and less headache to just patch that area up with plasterboard and give it a timber backing. I'll move the exhaust fan to a different area. Might repaint the ceiling as well….

    For the kitchen, thinking I patch that original hole and put the new hole more inward so it sits completely within the exhaust flue.

    I've been quoted around $200 for someone to do it. Tossing up whether I should just get someone in or do it myself for the learning experience.

  • Euphemistic on 06/05/2023 - 19:32

    This is a question best answered by making up your own mind on the preferred method based on the range of methods you find on a video sharing platform

    TLDR: search YouTube.

  • AngoraFish on 06/05/2023 - 21:20
    +1

    Thinking about this some more, I also had the exact same issue with the fan. Instead of relocating the first fan I bought a new one to go over the shower, had an electrician run electricity off the first fan to the new fan, and now both run at the same time off the same switch. Can't say that it's completely removed the mold building up, but I now have twice the suction I used to have and it's certainly improved things.

    • follow on 06/05/2023 - 22:21

      The noise would be killer 😂

  • bmerigan on 06/05/2023 - 22:03
    +1

    Note that the timber backing doesn't have to cover the entire hole, just enough for the new plaster to be screwed to, like a strip across each corner or edge.

    • follow on 06/05/2023 - 22:14

      good point. might make a larger cut to an area I'm unlikely to install something in

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