How to remove black mould on Colorbond roof?

[Cranswick]

Hi l got a small section on my colorbond roof from top to bottom of steaks of what looks like black moud or fungus , l am not able to climb on the roof but was thinking of spaying it with either bleach or cleaning vinegar , which is more effective and can either damage or stain the coating of the colorbond roof

[MitchellMc]

Hi @Cranswick,

Maintenance washing of the Colorbond sheeting should be as follows:

• Wash the surface with a mild solution of pure soap or mild non-abrasive kitchen detergent in warm water.

• Application should be with a sponge, soft cloth or soft bristle nylon brush, and should be gentle to prevent shiny spots.

• The COLORBOND® steel and ZINCALUME® steel should be thoroughly rinsed with clean water immediately after cleaning to remove traces of detergent.

Never use abrasive or solvent type cleaners (turps, petrol,kerosene, paint thinners) on COLORBOND® steel and ZINCALUME® steel.

I am unable to confirm whether bleach or cleaning vinegar would work, as they are not listed as suitable under the cleaning guide.

If you are not able to access the roof, it might be worth enlisting the services of a professional who is knowledgeable about cleaning Colorbond.

Please let me know if you have any questions.

Mitchell

[Cranswick]

thanks, l already sprayed it with vinager , can vinigaer harm the roof coating, could a plumber do the job of cleaning it

[MitchellMc]

Hi again @Cranswick,

Vinegar is quite acidic, and while it's often used as a household mould remover, it's not listed by Bluescope as a recommended cleaner for Colorbond. That said, a one-off light application is unlikely to do major harm, especially if it’s rinsed off promptly and hasn’t been left to dry or sit for too long. To be safe, I’d recommend rinsing the area with clean water as soon as you can to remove any residue and prevent potential long-term effects on the coating.

As for who can help, a plumber typically wouldn’t be the right professional for this type of work unless they also handle roof maintenance. You’d be better off contacting a roof cleaner or someone who specialises in Colorbond roof maintenance. Just make sure they’re familiar with the correct cleaning methods to avoid damage.

Mitchell

[Cranswick]

Before spending money on someone to do it, l was wondering if theres a roof cleaning liquid at bunnings that safe for colorbond roofs l could try and spray on it

[MitchellMc]

@Cranswick, the only product recommended for use on your Colorbond steel sheets is a mild dishwashing detergent in warm water. All of our outdoor cleaning products contain chemicals and are not recommended for use on Colorbond.

Mitchell