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Moldy Ceilings, how to treat it once its there.

Repaint Pro - Painters Gold Coast


Moldy Ceilings, how to treat it once its there.

Can you paint over moldy ceilings. Here on the Gold Coast, painting ceilings has always been an issue in wet areas like bathrooms.

For years we have only ever used very high quality low sheen paints or semi gloss in these kind of high moisture areas. The thing is, builders have never really stipulated the use of anything other than ceiling paint in bathrooms which due to its flat appearance soaks in moisture like chalk, hence all the trouble we now with mould, flakey paint and staining. Mold and the discoloration it causes as it eats through porous painted surfaces. Mildew can show up in patches of green, brown, or black, and it can appear fuzzy, slimy, or even powdery. As mildew eats through the painted surface, it destroys the integrity of the paint film, allowing moisture to enter.

In some cases, mold can be difficult to discern from simple dirt. The easiest way to test a surface is to place a drop of common household bleach (5% sodium hypochlorite) on the suspect area. If the black stain starts to disappear it is mould, dirty marks will remain black.

Painting over mildew is only a temporary fix to an ongoing problem. The mold will continue to live and spread beneath the paint, and the mildew will eventually just bleed through. Some paints are formulated with mildew inhibitors, but an inhibitor is just that, it’s not a mould killer! The mould needs to be dealt with 100% first.

Warning: Do not add household cleaner or any other product with ammonia to the solution. Mixing chlorine bleach with ammonia will release toxic gases.

Mold Removal with Vinegar

Vinegar is a mild acid which can kill 82% of mold species. However it also has the advantages of being natural and safe. Vinegar is non-toxic and doesn’t give off dangerous fumes like bleach does.

How to Kill Mold with Vinegar

To kill mold with vinegar, use white distilled vinegar which you can buy cheaply from the supermarket.

  • Pour some vinegar into a spray bottle without watering it down.
  • Spray the vinegar onto the moldy surface and leave it to sit for an hour.
  • Wipe clean the area with water and allow the surface to dry. Any smell from the vinegar should clear within a few hours.

If you want to use vinegar to prevent mold growing on surfaces just spray vinegar on the surface and leave it. Repeat this every few days to ensure the surface will stay mold-free.

You can even mop your tiled bathroom floor or other hard non-porous floors with vinegar if you are worried about mold growing on them.

Once the mildew is gone, you can paint the area. To prevent a recurrence, you may want to select paint with a mould inhibitor. Paint made with zinc oxide is more resistant to mildew than paint with titanium dioxide.

Please, don’t paint over mould to hide it. In the short term and long term your causing yourself more work, more cost and wasted time.


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Stephen Lockyer

Professional painters and Decorators on the Gold Coast. Serving all your interior and exterior painting needs.

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