When should I get someone to check my old Decramastic Roof?

Decramastic roofing tiles, also known as Decrabond or pressed metal tiles, were widely used in New Zealand during the 1970s and 1980s. Made of galvanised steel with a bitumen overlay, the tiles were known for being lightweight and easily installed. This very feature, however, makes the older tiles vulnerable to deteriorate over time, so maintenance and replacement are often necessary. If your home has an older decramastic tile roof from the 1970s and 1980s, repair or replacement may be a consideration. Here is a look at what causes such deterioration and the best ways to remedy the situation.


All roofing materials degrade over time but when the original decramastic tile roofs get older, the result can be far more unsightly. The surface coating and texture of many less expensive types of older tiles are believed to be highly vulnerable to changing temperatures. If your roof dates back to the 1970s and 1980s it’s recommended that you get a professional like Cooper Roofing to assess the old tiles before undergoing roof repairs or replacements.

Weather Damage

Driving rain, strong winds and direct exposure to New Zealand’s harsh UV rays combine over time to degrade old decramastic tile roofs, resulting in surface coating damage, dented tiles, loosened nails, chipped paint and cracks. While such damage is often repairable, basic patching techniques aren’t usually viable or recommended especially with older tiles.

Cracks and Dents

While walking on a roof is often justified during cleaning or repairs, decramastic tiles are easily cracked and damaged when subjected to such pressure. Unlike a dent in a vehicle, you can’t just pop a roof dent up to solve the problem. Older tiles are especially fragile due to having lost their original malleability. Attempting to pop up a dent may cause the tile to split, furthering the need for repairs or replacements. Modern decramastic tiles are far more heavy-duty and durable, so the chance of splitting in the future is no longer the issue it is with older tiles.

Organic Growth

Algae, lichen, moss, mildew and moulds easily grow on older decramastic tiles – resulting in the secretion of harmful acids that weaken the metal tile elements, causing leaks and a very unsightly, green-coloured growth on roofs. As the metal is eroded, rust can form on the surface which will be hard to detect because of various organic growths. Additionally, certain crawling and flying insects – which also cause damage – find such juicy growth delicious. These pests will be encouraged to make your roof their home causing further damage.

Replacing your Decramastic Roof

Your roof is obviously one of the structural elements of your home facing the most damage. It’s that part of a building that instantly and regularly comes in contact with weather components. The combination of extreme weather and temperature changes, dirt and other wind-borne elements leave an impact on roofing materials. Choosing between re-surfacing and a complete re-roofing job depends on the level of damage and deterioration to your roof.

Fortunately, the modern age of stone-coated Zincalume metal roofing is upon us, and an increasing number of homeowners opt to install and upgrade tiled or other roofing materials with new Gerard Roofs pressed metal roof tiles. Over time, metal roofs add lasting value to homes where other roofs may diminish in value. Here are a few examples of the advantages of Gerard Roofs tile roofing.

Life Expectancy

Unlike other roofing materials, the new generation of Gerard Roofs roofing tiles incorporate technologically-advances such as Zincalume protected steel, which gives tiles a longer service life than the old galvanised roofing tiles. The new generation metal tiles from from Gerard Rofos come with a 50 year pro-rata weather-proof warranty.

Variety of Styles

Coated metal roofs not only last longer, their very appearance has changed compared to old decramastic roofs. They are available in a variety of styles, in 32 colours and finishes, ensuring that you purchase a product that compliments your home perfectly.

Energy Efficiency

Efficiency is always a concern, so it always pays to research before going ahead with an order.The availability energy-efficient materials also ensures far less maintenance and overall weight on your home. Preserving the structural integrity of your home is always a foremost concern. Gerard roof tiles put less strain on the foundations and supporting beams.

Whatever you do…

Just because your roof is out of sight, it is still a vital component of your home – you cannot afford for it to be out of mind. If you’re in any doubt about your 1970s or 1980s decramastic roof please get Cooper Roofing to assess the old tiles before undergoing roof repairs or replacements. We will visit your property and give you a free assessment.