The short answer is no. But why? And what other cleaning options are available? Let’s dive right in.
Say 'No' to Roof Pressure Cleaning
Pressure cleaning your metal roof can damage the paint, stripping the protective layer that helps increase the lifespan of your Colorbond roof. Pressure cleaning is cheaper, often half the cost of a soft wash, but what you end up saving for in cleaning costs you’ll pay for in maintenance costs. An extra few dollars spent now will mean you will likely get years of extra life out of your roof. And considering that a new colourbond roof can be $40,000-$100,000, isn’t it worth the extra care?
Pressure washing strips off more of the baked-on paint than you’d like. Many businesses offer pressure washing of roofs as a service and it is wild that they are allowed to, but unfortunately the industry is not policed.
From what we’ve seen, Colorbond roofs normally last about 45 years, especially on the Central Coast where we are closer to the ocean.You want to get every year you possibly can out of its lifespan because replacing a roof is not cheap.
And I’ll be completely honest here: at the time of writing this article, I’ve been in the cleaning industry for a bit over five years. When I first started out, we did actually pressure clean Colorbond roofs.
I remember one roof in particular that ended up looking like a zebra because the paint had come off in strips. Fortunately, this customer was intending to get work done to their roof so it worked out okay, However I learned my lesson: exercise extreme caution with Colorbond roofs.
And then over the course of two further jobs when we were pressure cleaning Colorbond roofs, especially light colors like Shale Grey and Surf Mist, paint would come off in huge quantities. When you hose down or walk on many Colorbond roofs, a little bit of degraded paint will often come off, but not in these quantities.
I remember two jobs in particular that caused us to change our approach, one job we walked away from entirely and another job we pivoted to a gentler but more time consuming cleaning approach.
Ever since then, about three years ago, we have never pressure cleaned another Colorbond roof.
And funnily enough, that is exactly what BlueScope Steel, the manufacturers of Colorbond, recommend.
So, if you can’t pressure clean your Colorbond metal roof, then how are you supposed to clean it?
Well it’s not a mystery, BlueScope Steel, the manufacturers of Colorbond, tell us exactly how.
Say 'Yes' to Roof Soft Cleaning
Soft washing is the process of using a chemical product to do the cleaning instead of high pressure water blasting. The process is to spray diluted sodium hypochlorite (also known by its household name, bleach) onto the roof area. It’s also the exact same stuff, known by its other name chlorine, that you put in your pool to keep it clean. Even a saltwater backyard pool has chlorine! Saltwater pools convert salt to chlorine to keep the pool clean.
Mind you, we use stronger quantities than you find in a swimming pool. And good thing too, because the results are amazing.
You leave the product on the roof for a few minutes and give it a scrub if it needs it with a soft-bristled nylon brush. Colourbond recommends this choice of brush because other tougher materials can leave shiny spots on the roof making it obvious where the roof was scrubbed. Then, you hose off the product with copious amounts of water.
By following BlueScope Steel’s directions, the results are an awesome looking roof that doesn’t get the paint or lifespan ruined. A small amount of oxidised paint that has degraded will usually be removed by the cleaning process, but this happens even when you gently run your finger over the roof, so it’s to be expected and is completely normal.
These are the instructions to follow in order to keep your roof in good condition! We have seen many roofs made worse because these instructions weren’t followed. In fact, feel free to view the instructions direct from the manufacturer here: BlueScope Steel – How to Identify & Remove Fungus
How Often Should Roof Cleaning Be Done?
This isn’t a process that you would do every six months.
For this cleaning process requiring chlorine, get the roof cleaned when it gets dirty. Some roofs need it after 3 years. But for most roofs, at about 7 years old is when we have a lot of phone calls from customers asking about a clean. By the time a roof is about 10 years old, they pretty much all need a good clean.
If you want to clean your roof more regularly, Colorbond recommends a more gentle cleaning process, such as hosing down the roof with plain water or using detergent and a soft bristled brush. But when you have real stubborn debris on the roof such as fungus, algae, bacteria and/or mold growing on your roof, the chlorine is the way to go.
Is Pressure Cleaning Your Roof Ever OK?
If you are planning to get your roof painted, then soft washing is not the answer. Pressure cleaning might be appropriate here but talk to your roofer about this one. Roof preparation for painting is not our area of expertise.
Need a Hand For Your Roof Cleaning on the Central Coast?
Here at Shine Bright, this is exactly the process that we use when we clean your roof. We want to increase the lifespan of your roof, not decrease it.
Ensure that you choose a cleaning company that is going to soft wash your roof, not pressure clean it. If you’d like to ensure that your Colorbond roof is in great hands, get in contact with Shine Bright Property Maintenance today. We’d love to help with your roof cleaning wherever you happen to be located on the Central Coast. We work from Killcare to Terrigal, up to Toukley, and everywhere in between.
Sources
- BlueScope Steel – How To Identify and Remove Fungus
https://www.bluescopesteel.com.au/howto/identify-and-remove-fungus - Colorbond – Why Choose Colorbond
https://colorbond.com/why-colorbond-steel/technology - BlueScope Steel – How to Maintain Colorbond Steel and Zincalume Steel
https://www.bluescopesteel.com.au/howto/maintain-colorbond-steel-and-zincalume-steel
