Roofs · 3 min read
Can you water-blast a Colorsteel roof?
Why high-pressure water-blasting is risky on Colorsteel and coated metal roofs, and the safer way to clean them.
- High pressure can damage the paint coating on coated steel
- Roofing manufacturers generally recommend gentle cleaning
- A low-pressure soft wash is the safer option
It’s one of the most common questions we get, and the short answer is that you shouldn’t. Colorsteel and other coated steel roofs rely on their paint system to protect the steel underneath.
Why high pressure is a problem
A high-pressure jet can wear, chip or lift the coating, especially around fixings, laps and older or weathered areas. Once the coating is damaged, the steel underneath is exposed to moisture and corrosion. Water forced under laps and flashings can also end up where it shouldn’t.
What manufacturers recommend
Roofing manufacturers generally recommend gentle, regular washing rather than aggressive cleaning, particularly in areas rain doesn’t wash naturally, like under eaves. Check your roof manufacturer’s maintenance guide, as following it can matter for your warranty.
The safer way to clean a metal roof
A soft wash uses a cleaning solution at low pressure to kill moss and lichen, then rinses the roof. It cleans without the force that damages coatings.
Also clear your gutters at the same time. Debris washed off the roof ends up there.
Frequently asked questions
How often should a Colorsteel roof be cleaned?
Most benefit from a soft wash and treatment every 2 to 3 years, with sheltered areas rinsed more often.
Can I walk on my Colorsteel roof?
Walking in the wrong place can dent the profile. If you need to go up, walk on the purlin lines, or leave it to a professional with the right access gear.
Maidly looks after homes across Christchurch with eco-friendly methods and a 100% work guarantee on every service. Request a free quote.