While natural slate, specifically natural slate originating from Wales, is typically preferred for its overall longevity and strength, choosing the best roofing slate will involve considering a number of factors.
This guide will explore various types of slate roofing, including natural and synthetic slates, slates from different countries, their features, and classifications to help you determine which option is best suited for your roofing project.
What is the Best Roofing Slate?
Natural slate roofing is usually considered the best option when compared to synthetic slates because of its unmatched longevity, aesthetic appeal, and strength. However, the best roofing slate for you will depend on key factors such as durability, aesthetics, budget, and the specific needs of a project.
Among natural slates, Welsh slate is often regarded as the highest quality for several reasons, such as its durability, fine-grained aesthetic appeal and weather resistance, but other popular slates include Spanish and Brazilian slates.
How Slate Roofing Classification Works
Slate can be classified into 12 lithotypes, which are categories based on two key factors: colour and petrography. These characteristics stem from the slate’s depositional environment and its metamorphic transformation, and include:
- Black-grey, green or purple-red colours; and
- Low-grade slate (0), Slate s.s. (1), Phyllite (2) or Schist (3) petrography.
The classification “ST” refers to a unique and rare category of rocks used locally for roofing, which are not of metamorphic origin. On the other hand, “R1a” represents a mix of roofing slates composed of green and red-purple rock types.
These lithotypes can be seen clearly in the diagram below.
5 Types of Roofing Slate & Features
There are two main types of slate, natural slate and synthetic slate, both of which have a number of roofing slate subtypes within them. Let’s take a closer look.
Natural Slate Roofing
Natural slate roofing is widely thought of as the best and most durable type of slate and is mainly categorised by its country of origin. The most common areas where natural slate is found and produced into roofing material include:
- Spain
- Brazil
- Wales
- China
- Argentina
- Cornwall
- Canada
Below, we’ll look into a few of these popular natural slate roofing areas in more detail, covering what type of roof slate they produce and the lithotype classification of their natural slates.
Spanish Slate
Main Lithotypes: B1, B2 and G2
Natural Spanish slates are highly regarded in the roofing industry for their quality and durability. Known for their dark, consistent colour and fine grain, Spanish slate roof tiles are often thicker, more uniform, and easier to install compared to other types. These slates tend to have excellent weather resistance, making them ideal for varying climates.
Spanish slate is also popular due to its relatively affordable price and its balance between aesthetic appeal and longevity, making it a favoured choice in both residential and commercial projects worldwide.
Brazilian Slate
Main Lithotypes: B0, G0 and R0
Brazilian natural roof slate is known for its versatility and wide range of colours, typically featuring shades of black, green, and reddish tones. Brazilian slate is generally thinner and lighter than other varieties, making it easier to handle and more cost-effective for transportation and installation.
Despite its lighter weight, Brazilian slate maintains good durability and weather resistance. Its textured surface gives it a unique aesthetic appeal, often favoured in both traditional and contemporary architectural designs. However, it may require more careful installation due to slight variations in thickness and surface finish.
Below, you can see the aesthetic differences between the Brazilian slate (B0) and Spanish slate types B1 and B2.
- B0: Brazilian metalutite, matte appearance, rough surface
- B1: Spanish slate, fine, glossy surface
- B2: Spanish phyllite, the surface scales are produced by the greater metamorphic recrystallisation
Welsh Slate
Main Lithotypes: B1 and R1
Natural Welsh slate is renowned for its exceptional quality and longevity, with a life expectancy of over 100 years, even in harsh weather conditions. This makes Welsh roof slates particularly well-suited for the unpredictable British climate.
Welsh slates are known for their dense composition, and highly resistant to water absorption and frost damage, helping to maintain their durability across generations. Their consistency in thickness and fine-grained texture also contribute to easier installation and a strong aesthetic finish.
With a classic blue-grey or heather colouring and fine-grained texture, Welsh slate can also provide a premium, high-end look to any structure.
Synthetic Slate Roofing
Synthetic slate roof tiles are designed to mimic the appearance of natural slate while offering a more cost-effective and lightweight alternative. Made from materials such as polymers or rubber, these tiles are often easier to install, requiring less structural support compared to natural slate. However, natural slate is known to be a more robust, durable and aesthetically pleasing option.
There are some different types of synthetic slate roof tiles, which we’ll look at in more detail below.
Fibre Cement Slate
Fibre cement slate tiles are a composite roofing material made from a blend of cement, cellulose fibres, and other synthetic materials. These tiles offer the aesthetic appeal of natural slate but at a fraction of the cost. Fibre slates are often lightweight, fire-resistant, and easier to install than traditional slate, making them a practical option for both residential and commercial properties.
Fibre cement slates also have good durability and weather resistance, though they usually don’t last as long as natural slate.
Recycled Slate
Recycled roof slate is a popular choice for environmentally conscious builders and homeowners that are looking for more sustainable roofing solutions. It is made from reclaimed slate tiles or composite materials that are repurposed into new roofing products.
Recycled slate retains the natural look and durability of traditional slate, with the added benefit of reducing waste and minimising the environmental footprint. This green roofing material is ideal for those aiming to incorporate eco-friendly practices into their construction projects without compromising on aesthetics or performance.
Read More: How To Lay Slate Roofing Step-By-Step
Closing Thoughts
When it comes to choosing the best roofing slate, it’s important to consider the unique needs of your project, from durability to budget. Whether you’re looking for premium natural slate or cost-effective synthetic options, C Kearney Roofing specialises in high-quality slate roofing replacements.
With our expert team and top-notch service, we ensure your roof not only looks great but stands the test of time. Contact us today to discuss your roofing needs and find the perfect slate solution for your home or business.