About Your Roof: 

Cleaning Colorsteel Roofs

Cleaning Colorsteel and Colorbond roofs is essential home maintainence.
If left uncleaned, algae and lichen cause severe damage to the Colorsteel coating, peeling it back to bare steel.  Regular roof cleaning will prevent this damage from occuring, ensure you comply with Manufacturers Warranty conditions and extend the service life of your roof

How to Clean & Maintain Colorsteel Roofs

Your new Colorsteel roof will resist algae and lichen growths for 4 to 5 years under normal conditons
Algae and lichen will then begin to naturally grow when conditions are right – temperate climate with regular rainfall and a source of spores.

These growths not only look unsightly – they will cause severe damage to the high quality factory colour coating, peeling it back to bare steel.

Bio-Shield will kill and remove algae and lichens and maintain your Colorsteel roof without harsh chemicals, pressure cleaning or washing down, – its a simple, quick and no mess application.
Regular cleaning is recommended by Colorsteel to maintain the protective coating.


The Bio-Shield Cleaning Process

Lichens are easy to kill with Bio-Shield, however, a specific formulation and application method is used on your Colorsteel roof to ensure an effective kill of black algae.

Once applied to your roof, Bio-Shield will kill all the moss, algae and lichens within 3 to 4 hours.
You will notice distinct colour changes in the lichens over the next few weeks as the dead growths start to breakdown. Black algae do not show these colour changes.

After 2 to 3 months, the cleaning process will be more visible, as rainfall and wind begin to remove the dead growths, revealing more and more of your roofs original colour.

After 12 months, the roof will be fully clean and stay clean for up to 2 years.

Maintain your roof with Bio-Shield

We recommend re- application of Bio-Shield every 2 to 3 years, to keep the roof clean and protected.
With regular applications of Bio-Shield, algae or lichen spores and light re-growths will be quickly removed, and the roof will stay clean for another 2 to 3 years.

Lighter colours will show up even low levels of re-growths so should be treated with Bio-Shield every 2 years.

Water Blast / Pressure Cleaning:

Bio-Shielld is the best option to clean and maintain a Colorsteel roof. 
These roofs should only be water blast cleaned as preparation for repainting, never to remove lichen growths.
For repainting, apply Bio-Shield and wash the roof down after 2 to 3 weeks, then recoat the roof with a high quality acrylic coating system.

2 Year Guarantee

Bio-Shield applications are covered by a written 2 year Warranty.

Expert Colorsteel Roof Cleaning

Roof Cleaning Ltd are genuine specialists in Bio-Shield roof cleaning, with over 40 years experience and more than 10.000+ roofs cleaned and treated with Bio-Shield®.
Expert Application, Proven Performance, Reliable Results

Is Bio-Shield safe to use on my roof?

Yes, Bio-Shield has been used commercially and safely for over 37 years and on more than 9700 roofs in New Zealand. It is not acidic, not a bleach and not abrasive like pressure washing, so won’t cause any damage to the color coating, gutters, skylights, vents, solar panels or other fittings and fixtures commonly found on roofs.

How long will my roof take to clean up after being treated with Bio-Shield?

 A general guideline for the clean up time after initial Bio-Shield application would be 3 months and up to 6 months, if the growths are heavy and well established on the roof. 
Other factors that affect clean up times are the pitch of the roof and how much rain falls on the roof once the dead growths have begun to break down.

 Roofs that have previously been cleaned with Bio-Shield and is having a 2 or 3 yearly maintenance treatment can clean up in a matter of weeks if the growths are light.

Can I still collect rain water from my roof once its been treated with Bio-Shield?

Yes, Bio-Shield is water based, water soluble and bio-degradable so it is safe to use on roofs that collect drinking water. The storage tank will be disconnected before application and can be reconnected after a minimum of 3 to 4 weeks and at least one day of rain has flushed the roof clear of Bio-Shield residue.

A diverter can be installed on the tank inlet pipe, on above ground tanks to isolate the water tank form the roof and make reconnection and any future disconnections a 15 second task. No need to remove down pipes or fit expensive and ineffective diverters to the down pipes

We do not recommended cleaning a roof over the summer months, from January to March , in drier areas as there may not be enough rain to flush the roof and refill the tank after it is reconnected.

How often should my roof be treated with Bio-Shield?

Concrete tile roofs should be treated every 2 years to maintain them in a clean condition. Regular treatments will help to preserve the factory colour coating in good condition. Roofs that have been re-coated or resurfaced with and acrylic coating system can stay clean for up to 4 years.

The micro climate around a roof will have a large influence on timing between the maintenance treatments.

If there are trees near the roof, the roof is steep pitched or birds habitually use the roof to rest or nest, annual or 2 yearly treatments may be required to keep the roof clean.

My roof was treated by another company and it did not clean up. What happened?

Unfortunately some applications by companies that are not specialists in roof cleaning, for example house wash, gutter cleaners or handymen, are not being done correctly and leaving a patchy clean up from incorrect or incomplete application.
Bio-Shield gives a faster and superior clean up on concrete roofs and roofs treated with Bio-Shield are guaranteed to clean up.

Will Bio-Shield kill my plants?

Bio-Shield can not kill plants, it is a surface santizer, not a systemic garden spray.
It can safely be used on lawns to kill moss and on tree trunks and branches to kill lichen.
In sunny conditions, some delicate leaved plants can get spotting on leaves from contact with Bio-Shield so any affected plants are hosed down after the application.

Edible plants near the roof are always hosed down after the application.
Bio-Shield is fully bio-degradable when in contact with organic matter and soil

Is Bio-Shield harmful to animals and pets?

The active ingredient in Bio-Shield has been safely and continuously used in the the food industry, in hospitals, veterinary clinics and zoos as a hard surface sanitiser for over 60 years.

The only precautions we take are to move feed bowls and toys away from the roof, and flush them out after the application is complete.

Is there a Guarantee?

When Bio-Shield is applied to any roof we provide a written 2 year guarantee on the effectiveness of the application.

While there are conditions to this warranty, these are common across all roof treatments as they relate to the  situation, pitch and conditions around the roof, not the quality of the application.

You should be aware of the limitations that the above conditions – Read More