Gerard Roofs

Committed to Canterbury


Only time can heal the wounds that the earthquakes have caused the people of Canterbury. At Gerard Roofs Christchurch, and throughout the Fletcher Building Roof Tile Group, we are committed to doing everything we can to help with rebuilding.

If you’re among those who have been forced to rebuild your home or replace your roof, a Gerard lightweight, pressed steel roof is well worth investigating further.


No type of building went unscathed in the disaster but homes with Gerard roofs fared better than most.

A Gerard roof is a well-proven system of individual pressed steel tiles fixed in a unique way that effectively locks them together to form a single robust structural unit.

The idea was developed here by Kiwis, for New Zealand conditions; steel-tile roofs are lightweight and ideally suited to earthquake prone areas.

With the gradual resolution of zoning and release of Government and insurance company settlements, more and more people are confronted with decisions about reconstructing their homes. For most this involves careful thought, planning and important choices.

Below are some answers to frequently asked questions regarding roofing for Canterbury in the aftermath of the earthquake.

Gerard Roofs Christchurch 0800 857 857

A. The safety of your family and possessions should be your first priority. With roofing, the key considerations are weight, structure, fixing, and of course, cost.

Weight is important. Because the framing for a house is designed with roof weight in mind it is generally possible (depending on the slope of the roof) to replace a heavy weight roof with a lightweight roof such as steel tiles from Gerard Roofs. Putting a heavyweight roof on framing that has been designed for a lightweight roof normally requires upgrading the framing and structure underneath. Because heavy weight roofing requires a more substantial structure beneath it, this will add to the cost.

Keeping a roof on is important in an earthquake and in wild weather conditions. Every Gerard Roofs lightweight steel tile is nailed to the roof structure at 90-degrees to wind up-lift forces, making them highly secure in strong winds and earthquakes.

A. An independent assessment of housing in Canterbury after the 7.1 magnitude earthquake in September 2010 was conducted by University of Canterbury engineering specialists who found “most common type of damage for older buildings (more than 15 years old) was chimney collapse.” This report went on to say:

"Chimney collapse on to corrugated steel roofing often caused no further damage, depending on the height of the chimney, but some fell through the roof or caused rafter failure. Chimneys falling on to tile roofs (concrete or clay tiles, or slate roofs) more often fell through into the house, sometimes causing further structural damage and potential loss of life."

To date we have not received any reports or seen any evidence that shows Gerard lightweight steel tile roofs performed any differently from corrugated steel roofing. Where chimneys needed to be removed the repair generally required only a few tiles to fill the void.

A. From a technical point of view, certainly not.

Replacing your clay tiles with a Gerard lightweight steel tile roof will require no changes to the framing structure. However, new roofing battens and underlay will be required, as can be the case when replacing with other roof types.

In a July 2003 report the New Zealand government recognised that heavyweight roofs on existing school buildings caused extra stresses. As a consequence, many schools had their roofs replaced with lightweight steel tiles. Your house can benefit in the same way.

Below are the recommendations from a Ministry of Education commissioned report titled "Technical Guidelines for Structural Mitigation Work":

"As long as they are adequately connected to their foundations and do not contain a heavy roof or ceiling, school buildings are expected to perform adequately during a severe earthquake almost irrespective of configuration. The major reason for this is the lack of seismic mass at roof level generating significant lateral forces. This is not the case if the building has a heavy tile roof. All buildings with heavy tile roofs have been identified.

Recommended Action

All heavy tiled roofs are required to be removed and replaced with a lightweight roof. The only exception to this is if the school wants to retain the tile roof and this would need to be agreed to by the District Property Manager. In the latter circumstances, a detailed analysis of the building would be required and strengthening provided..."

From an insurance point of view, you will need to talk to your insurance company as they may decide it is cheaper to simply replace the damaged area. However, there is a shortage of second-hand clay tiles and the price of these has increased substantially.

A. A Gerard lightweight steel tile roof can be as little as one tenth of the weight of the equivalent concrete or clay tile roof.

Every Gerard tile is fixed with a minimum of eight separate fasteners, so it is highly unlikely individual tiles will be dislodged by earthquakes or high winds.

Gerard Roofs steel tiles are available in a number of profiles and colours so you should be able to find something that closely matches the look of your current roof.

A. Gerard Certified Installers will measure the roof, and once they have the OK to proceed, will remove the old roof and replace it with lightweight steel tiles.

This usually involves replacing the roof one section at a time to avoid undue exposure to the weather. You can remain in your home while the new roof is being installed. The roof of an average 230sqm house will take around four days to replace.

A. No. Gerard roofs can only be installed by Gerard Certified Installers. This means that we are able to offer a 50-year pro-rata product warranty. Our installers have all the equipment necessary to remove your old roof and install a new Gerard roof in a safe and professional manner.

A Ideally you should have an idea of roofing type before you start, although colour and profile can often be left until later. Because Gerard Roofs steel tiles weigh less than concrete or clay tiles, the framing of a new home can be designed differently, often resulting in significant savings.

If your house is already designed for a heavy roofing material such as concrete or clay tiles and it meets the minimum slope requirements of 12 degrees, substituting Gerard lightweight steel tiles is sim.

A. The cost of a roof varies significantly based on the roof's complexity, but typically a Gerard lightweight steel tile roof is cost-competitive with longrun corrugated iron and clay or concrete tiles. When comparing roofing quotes, check that all costs have been included, such as roofing battens and paper underlay. Remember also that heavyweight roofs such as clay or concrete tiles can also require more extensive supporting structure which can add to the final cost.

A. This is a little hard to quantify in the absence of data for all roofing types. What we can say is that Gerard lightweight steel tiles are manufactured from recyclable steel and we have ISO 14001 certification, an international standard. This means we have procedures in place to constantly measure and reduce our environmental impact.

A. Gerard Roofs is part of the Fletcher Building Roof Tile Group. We have four roofing plants around the world and sell into over 120 countries.

The New Zealand plant alone has ample manufacturing capacity for the whole of Canterbury.

We have plenty of installation capacity in Canterbury. But to be sure, we have also surveyed our nationwide network of Geraard Certified Installers and have identified teams able to move to the region to help out if need be.

A. Your first point of contact is Gerard Roofs in Canterbury. You can call them on 0800 857 857 to discuss your requirements and arrange for a representative to come to your home.

No obligation FREE QUOTE

and a free information pack

If you have a heavyweight concrete or clay tile roof that was damaged in the earthquake, fill in this form to find out how you can replace it with a modern, lightweight Gerard steel tile roof.

Would you like: *
Are you: *

I have read the terms and conditions *

Any other enquiries, please phone 0800 857 857