Artificial slate roof tile History
Interlocking slate roof tiles, Composite roofing slates, Man made slate NZ, Imitation slate, synthetic slate,

The First type of Artificial slate roof tile is the Asbestos slate – They have been brought into this country since the early 1900`s original used on churches it came in a diamond shape pattern. There are still churches and the odd house still with this product on today.It shows it has stood the test of time. There was also an asbestos slate tile made in New Zealand up until 1979 when asbestos use was banned.

The second type of Artificial slate roof tile is the Fibre cement – In 1980 fibre cement slate tiles were manufactured to replace the asbestos slate tiles. They were smooth, dark-grey the compressed fibre cement tiles life expectancy in NZ was short. Even though they have been made in Europe for some time mastering production in New Zealand had mixed success. Some were failing between 8 years old up to 15 years well below what was claimed by the manufactures. Production in New Zealand stopped in the 90`s. There were some made in Germany since the 1970`s that have lasted well in early 2001 they were bought out by a rival company and the Germany factory was shut down. This enabled production to be shifted to Belgium which was producing a similar product. These Belgium made roof tiles are inferior to the German product they have failed in Australia after only 8 years. The manufacture has stopped exporting to both New Zealand and Australia due to this issue.

Reconstituted slate tiles, Interlocking slate tiles, Composite slate, Man made slate – are typically made up of 60-80% Recycled slate spoil. They were original produced in 1985 and imported in to NZ from the early 90`s and stopped 10 years later due to failures becoming apparent in the roof tiles.
These types of products have been made in Europe for 30 years as a cheap alternative to a genuine slate roof. It is industry acknowledged that while it is initially cheaper than real slate, the life span is considerable less than most other roofing products. These products still carry a manufactures guarantee valid in Britain and Europe only. One manufacturer gives 10 years the other 15 years. These composite slates have a life expectancy on average in Europe of 22 years. So in the life time of your roof you will replace it at least twice compared to a concrete or tin til. Three times compared to a Clay tile roof, possibly four when compared to a quality slate roof which will last a minimum of 80 years. So cost wise over time it works out more expensive than other roofing products based on history of these products in the UK.

The issues with an Artificial slate roof tile is they are prone to UV destabilisation. This breaks down the stability of the resins used to bind the slate spoil together. Which in turn leaves them vulnerable, as they become extremely brittle. As our UVI index in New Zealand is far greater than in England and Europe we see accelerated breakdown of the resin molecules in this part of the world. Based on the history of these products in New Zealand conditions, we have seen failures in these roofing materials on houses that are only 10-20 years old. They have not stood the test of time in the past. The critical issue remains some have failed to meet the performance requirements of the NZ building code B2. As they fail to meet standards for durability which states a minimum of 15 years. There are many other products cheaper that will out perform these types of products, tin, asphalt shingles, flat clay tiles, they may be worth considering. It is worth doing the research now to enable you to make informed decisions about what product would best suit you and will meet your expectations now and in the future. Problems start when failures occur in the product, you then find the product importer here is no longer around to back up there own guarantee and with no Manufacturer’s Guarantee here you are in trouble.

In comparison to other roofing products.

Fibre cement – 15-20 years UK Manufactures Guarantee (no longer imported into NZ due to durability issues)

Reconstituted, Composite slate tiles. Interlocking slates, UK Valid Manufactures 10 to 15 year roof system Guarantee ( stopped been inported in the 1990`s due to durability issues) started to be imported again in 2013

Tin roofing – 15-30 years NZ Manufactures Guarantee (depending on location)

Asphalt shingles – 30–50 years NZ Manufactures Guarantee (depending on type)

Concrete tiles – 50 years NZ Manufactures Guarantee

Clay tiles – 50-75 years NZ&UK Manufactures Guarantee (Depending on manufacturer)

A Grade Slate – 75 years + years UK Manufactures Guarantee (Depending on Quarry)