AHI Roofing, the New Zealand-based manufacturer of Decrabond roofing systems, is now providing 50 years warranty for its products in the Gulf countries instead of the earlier 25 years.

The warranty will be 25 years full, 25 years pro-rata on Decrabond products.

The Decrabond systems' seven layers of coating protects the steel substrate from corrosion and weathering, but most notably the use of zinc-aluminium coated steel gives the product six to seven times longer life than its galvanised steel counterpart, says a spokesman for AHI Roofing.

Established for more than 45 years, AHI Roofing continues to lead the way in steel-based roof tile systems. Producing over 10 million metres of roofing from its plants in New Zealand and North America, together with licensed production in Europe, Decrabond is now a familiar brand in over 70 countries worldwide, he says.

The base of every tile manufactured by AHI is a 26 gauge steel, coated on both sides with zinc-aluminium for corrosion protection.

The product development team at AHI Roofing in New Zealand has followed design trends worldwide to produce a range of products which offer the architect and owner a variety of choice to complement and enhance their architectural structures. The products include Decra Shingle, Decra Tile and Decra Shake.

Decra Shingle

A complicated four-directional corrugation and coating in two colours of natural stone chip are the unique features of this shingle.

Available in four colours, Decra Shingle provides consultants and architects with something completely new for the Middle East to differentiate their products from less innovative building surroundings, says the spokesman.

Decra Tile

The most popular profile in the Middle East, Decra Tile has been used in Gulf countries for over 30 years. Examples can be seen in the UAE, Saudi Arabia, Qatar, Bahrain, Kuwait, Lebanon and Egypt, he says.

Decra Shake

The timber shake roof is common in North America, but ineffective in the harsh Middle East climate. Decra Shake brings together the attractiveness of this style with the durability common to all Decrabond roofing products allowing for strength and beauty to be combined, says the spokesman.

"Decrabond is the simplest and quickest way to install a pitched roof. It is flexible and adaptable and can be utilised to meet almost any roof design or feature," he says.

Decrabond can be applied over a frame roof, steel structure or concrete pitch. (see Table 1)

Weatherproof

Decrabond roofing is approved to international standards and has independent test approval from certification bodies including ISO, BAA, BS and ASTM.

According to the spokesman, independent testing of Decrabond has proven durability against the following:

High speed/low speed, dynamic rain penetration: Up to 200 mm/hr rainfall.

Wind test: Up to 200 km/hr wind speed showing zero tile uplift.

Fire rating: US Grade A - zero burn/flame 760 deg C.

Hail: Zero penetration or cracking up to 90 mm diameter hail.

On the top and bottom of the tile, an epoxy primer is used for additional adhesion and protection. The natural stone chips are applied into an acrylic basecoat, overglazed with clear acrylic resin and the whole tile is oven baked to secure the surface coating. The coatings and stone finish are themselves covered by a 15-year warranty in any weather conditions. The effectiveness of this has been proven in the Gulf where products installed 30 years ago are still in use, says the spokesman.

Copycat Products

Due to the success of Decrabond in the Middle East, the last two years have seen the introduction of some copy-cat products from Africa and Asia, he says. "While at face value the products look similar, there are huge differences in performance."

He says independent tests have shown failure of these products as listed in Table 2.