FAQs

Metal roofing, steel in particular, is ideal for New Zealand conditions as it is a durable material.  Gerard’s pressed steel tiles are made up of a steel core with a protective zinc-aluminium alloy layer, and more layers of protective coatings making them one of the most durable roofing solutions available.

Metal roofs can last for decades, well outstripping the requirements of the New Zealand Building Code.  There are a variety of factors when looking at roof longevity, including environmental factors like coastal proximity or corrosive environments.  Gerard’s roof tiles enjoy a generous product warranty encompassing both perforation and surface coating.

There are many benefits to a metal roof over a concrete tile roof.  Gerard’s pressed steel tile roofs weigh approximately a tenth of the weight of a concrete tile roof and require fewer materials to support the roof’s weight.  Additionally, the high strength-to-weight ratio, high impact resistance, and unique fixing system make a Gerard roof safe and secure against almost anything nature serves up.

Metal roofing is often associated with long-run, corrugated iron, or tray roofing.  However, Gerard’s tiles are also ‘metal roofing’ and are made of steel with two coating options: satin finish or textured finish.

Metal roofing in general enjoys great product longevity, durability, and impact resistance, and Gerard’s steel tile range has additional benefits for homeowners including a shorter installation time, a great variety of styles and colour options.

Gerard’s textured finish is achieved by baking natural stone chips into layers of coatings to provide a robust, durable layer that adds an aesthetic dimension to the roof.  It also gives the added advantages of extra impact protection, and sound dampening qualities.

When choosing a roofing material for coastal homes, a variety of factors must be considered to ensure longevity in harsh marine environments.  Corrosive salt exposure, UV exposure, and wind driven rain are all factors in choosing a roofing material.

Materials like slate have excellent resistance to harsh coastal weather conditions, however, can be extremely expensive and are a heavy roofing material.  Extra structural support may be required to support the weight of this material.  Concrete tile roofing is slightly more affordable, is also durable, yet is a heavyweight material and may require extra support.

Metal roofing, like Gerard’s pressed steel tiles, are a lightweight, cost-effective, durable option that is relatively low maintenance.  Gerard’s coatings provide UV stability and corrosion protection ensuring a long-lasting finish.

It is best to discuss your specific project with a professional to help select the right product.

The time taken to install any roof will be dependent on the specific roof design.  Generally, Gerard’s pressed steel tiles will take a shorter time to install from start to finish than other metal roofs, such as long run, as all components can be measured and ordered off the plans prior to the roof installation.

Generally, metal roofing is a cost-effective roofing solution with great durability and product lifespan. The cost of a new roof will vary depending on the specific roof design, area the project is based in, the roofing contractor, and the chosen roofing product. 

Gerard’s roof tiles enjoy a generous product warranty with up to a 30-year warranty for perforation and up to a 20-year warranty for surface coating.

Yes, in New Zealand you can replace an old concrete roof with a lightweight steel roof.  In some instances extra bracing may be required, which is easily applied.  Your roofing professional can guide you for your particular project.

Repainting a steel roof as part of a maintenance programme is highly recommended to prolong the life of your roof.  Be sure to inspect the roof prior to painting to ensure there are no rust issues, and clean the roof before painting. 

For a Gerard roof, please see the Gerard Maintenance and Roof Care Guide for further recommendations.

While corrugated iron or longrun roofs can be costly to replace, metal tile roofs are very easy to repair if a tile is damaged.  A roofer can remove a singular damaged tile and replace it with a new tile, minimising replacement costs.

A Gerard metal tile roof is designed to be colour fade resistant using a layer system of proprietary coatings.  The UV-stable paint Gerard uses is approximately twice as thick as the coatings on other leading metal roofing manufacturers, ensuring a long-lasting, durable finish.

Penetrating through a roofing material when installing solar panel brackets increases your likelihood for leaks and long-term damage and may void roof warranties.  Gerard’s Standard Fastening metal roof tile range has an innovative interlocking solar bracket which allows for solar panel installation without penetrating the metal roof tiles.

With Gerard’s Concealed Fastening range, it may be possible to roof over asphalt shingle or long run roofing, depending on the quality of the structure of the existing roof.

With Gerard’s Concealed Fastening range, it may be possible to roof over existing asbestos-containing metal tile roofs, depending on the quality of the structure of the existing roof.

In general, roofs should be cleaned annually as a matter of preventative maintenance, including a moss treatment.  However, as a roof ages more frequent cleanings may be necessary.

Gerard’s recommended moss treatment, MossBoss, works to kill existing growth along with their spores that may remain dormant for up to two years before forming visible growths.

A new Gerard roof typically requires no moss/algae cleaning for the first five years and then should be treated annually with a moss treatment.

Organic growth like lichen and moss is a natural phenomenon that occurs on most permanent outdoor structures including your roof. Its appearance and extent is dependent on local conditions and can even vary on different parts of the same roof. Temperature and humidity, the pitch and orientation of the roof and the location of nearby trees are all possible contributing factors.

Left unchecked, organic growth can cause damage to the surface coating of your roof and can create ‘moisture traps’ that cause corrosion.

Choosing the right moss treatment for your roof is important to avoid damage.  Moss treatments including bleach or other hypochlorite-based cleaners may affect the roofs coatings, cause discolouration, or shorten a roofs life.

Gerard recommends using MossBoss for both satin and textured finish Gerard roofs as it does not contain any hypochlorite-based cleaners.

It is not recommended to use bleach or other hypoclorite-based cleaners on a roof.  The coatings on roofing, their materials, flashings, and fasteners may react to these cleaners causing damage.  It’s recommended to check with the manufacturer of your roof for maintenance guidelines and compatible cleaning materials.

If rainwater is collected from the roof for drinking, the water connection system should be disconnected from the tank before any chemical cleaning of the roof.

The system should remain unconnected for at least three heavy rainfalls to ensure the removal of any residue.  Alternatively, the roof can be thoroughly hosed down with clean water before reconnection.

Early stone coated metal tiles, known as decramastic tiles, were popular in New Zealand in the 1960s and 1970s.  These metal tiles were made using galvanised steel and stone chip embedded into a bituminous coating.   Thanks to innovations in the roofing industry, decramastic tiles have been superseded by today's pressed steel tiles.  And today’s tiles are a superior product with a long product life, high impact and corrosion resistance, and UV stable colours.

Metal tile roofs manufactured prior to the early 1980s often contained a low level of asbestos in the mastic or bituminous adhesive coatings.  These coatings don’t present any danger when contained in the roof, however they will need to be disposed of properly through specialists.

There are some indicators which can help you identify if your roof contains asbestos

1. Tile age.  If the tiles are manufactured in the late 1980s or later, it is less likely that they will contain asbestos.
2. Tile coatings. Asbestos was used in the coatings to adhere stone chip to steel tiles.  If the surface of your roof is painted with no texture, it is less likely to contain asbestos.
3. The tile profile.  Asbestos containing tiles generally has scalloped design.  If it does not have a scalloped edge, it is less likely to contain asbestos.

If you are unsure if your roof contains asbestos, prior to reroofing please consult a roofing specialist to conduct testing.