Your roof is exposed to an entire wealth of good and bad natural elements.

In Brisbane, it can be hit by hours of intense sunlight, smashed by hail and other debris, and soaked by heavy rainfall. If you live in an area where it snows, it can be covered in ice and water for hours at a time. As time progresses, these conditions can cause grime and algae to form, no matter how impervious your roof is. Because of these superficial and more malignant forms of damage, occasionally cleaning your roof can be a good idea. The best way of doing this? With a pressure washer.

Pressure washing - efficient and effective

In Australia, a large percentage of home have either tiled or metal roofs. For these two roof types, pressure washing is one of the most effective, efficient and risk-adverse roof cleaning methods available. While some chemical-resistant roofs may allow you to scrub them clean via certain chemical solutions (e.g. a chlorine solution), this method is also far more time-consuming. In the event that your roof isn't chemical-resistant, using such solutions could also cause unwanted damage.

For the above reasons, pressure washing is your best option. It can be used for anything from removing superficial grime to eradicating unwated algae buildup.

What you'll need for a pressure washing

The obvious first suggestion is a pressure washer. You have the option to other rent one or buy one. This really depends on which approach your prefer, but if you'll only be pressure washing your roof over a couple of days, renting one may be more financially feasible. If, however, you'd like to use it for several tasks that could pop up over time (the roof, cleaning the driveway, removing the grime off exterior walls, and so on), then an outright purchase may be a wiser financial choice. You can usually pick up a basic one for around $150 to $200. If you want a real high-end one, the cost could be much steeper, however.

Another thing you'll need isn't something that needs to be rented or purchased, but rather assessed. Remember that you'll be walking on your roof while using a pressure washer, so it's important to know the layout of your roof. This way you can note where hazards are. If your roof has notably steep slants to it, you'll need to proceed with additional caution. And don't forget to wear a pair of shoes that have plenty of grip, because once the water starts running across the roof a lot of its own grip will be lost.

When cleaning your roof

With pressure washing, it's best to start the process at the peak of your roof and then slowly work your way down from there. Be sure to aim the nozzle directly downwards against the roof - this helps avoid the issue of water shooting underneath sections where tiles or metal sheeting overlaps/connects. Ideally, you should hold the nozzle about 30cm away from the roof and run the pressure washer at medium pressure. It's important that you don't go above the medium pressure as the higher pressures could potentially damage your tiles or metal roof. If any grime or algae isn't coming off, slowly edge the nozzle closer to the roof until you see the grime/algae start to give.

You should wash the roof in small sections. The reason you should start at the peak is because it means the water will run off away from you rather than you constantly climbing up towards the peak with water in front of you. Still, even when starting from the peak, you'll encounter sections you've just washed. That's why small sections are best, as you can focus on completely removing all grime so that the section isn't as much of a slipping hazard as it would otherwise be with wet grime/algae. Proceed slowly to each new section and walk with extra care if the area is still drying. If you want, you can wait for sections to dry up before proceeding, but this will naturally make the cleaning process take a little longer. But it's better to take your time than to take a fall.

Please remember

Remember that cleaning your own roof should be something you do simply to keep your roof in a better condition for longer. However, it should not exist in leiu of proper check-ups by professional roofers. Much like how brushing and flossing your teeth helps keep in good condition between dentist visits, cleaning your roof will help give it a longer life while the occasional check-up will ensure it stays in good condition.

Just remember to be careful and meticulous when cleaning your roof. If you believe cleaning your own roof may be too risky, then you can always call in a professional to clean the roof for you.