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My Colorbond roof appears to have mould on it which has been there since I purchased the property. I’m wondering if there’s a way to clean it off? I have a pressure cleaner from Bunnings but unsure if that’s enough. Thanks!
Hi @Joan_J,
I'd suggest a bit of a combination between 30 Seconds 5L Roof Treatment Concentrate and possibly your pressure sprayer. You can either spray the product and leave it for up to 6 months before the lichen fully decays and washes off in the rain or spray as much as you can off now with your pressure sprayer before applying the product.
It's best to get the 30 seconds product on there as soon as possible and let it do its work. I'd recommend doing the work from a ladder if possible, as it would be pretty dangerous to get onto the slippery Colorbond roof whilst it's wet. Your pressure sprayer won't do much to the lichen unless you can get the nozzle up close to it. If that requires you to get on the roof, I would advise you to leave it to the professionals.
Unfortunately, you might find that the lichen has secreted destructive acids causing damage to roof materials. This might appear as a discolouration even after the lichen is removed.
Please let me know if you have any questions.
Mitchell
Hi @Cranswick,
It could be mould or mildew, though mould doesn't typically grow on a roof. Looking at the specifications of the 30 Seconds 5L Roof Treatment Concentrate it does say that it is suitable for Coloured steel. However, as mentioned in your discussion, chemical cleaners are not listed for use in the technical specifications of Colorbond steel.
This cleaner should work for most organic issues on a roof.
Mitchell
They've likely done testing and found it doesn't damage Colorbond @Cranswick. Given that they are recommending it for that purpose, I would say it's very unlikely that it would damage the roof.
However, if you can wait until Monday, I'd like to contact the manufacturer directly to get a definitive answer on Colorbond. The product description notes that it is suitable for coloured steel, though I'm not finding that information on the 30 Seconds website. There, it only states "steel roofs" and not painted steel roofs.
I think it would be wise to have this confirmed before applying it to your roof.
Mitchell
That's typically seen at points where the sheeting is damaged and the inner steel exposed, like on cut edges @Cranswick. It's unlikely to occur mid-sheet. Repair would be a process of sanding the area back, treating the rust and re-coating. I'm not aware of how costly that would be, and you'd likely need to get some quotes.
I wouldn't jump to that conclusion until the area is assessed; it's most likely some organic matter.
Mitchell
Heres a photo , can you tell me what you think the black stuff on the roof is , thanks
Hello @Cranswick
It appears to be mould and mildew along with a form of dust deposit. It does not appear to be a heavy rust infestation. In regards to the cleaner, Mitchell will be following this up with our supplier of 30 seconds. Let's wait to see what they have to say in regards to making sure that using the cleaner is safe.
If you have any other questions we can help with, please let us know.
Eric
