Roof Slates

At GNR, roof slating is among one of our core business practices.

Based upon a particular project, we consider the choice of slates carefully to meet client needs, those of any conservation restrictions, and the long term function of the proposed roof covering.

Below is a list of our most common slate types and some examples of their use cases:

Welsh Roof Slates 

Using Welsh roof slates is the epitome of traditional roofing practice. It can be confidently stated that Welsh slates and lead, installed correctly and in accordance with BS5534 and BS6915 prevail as the ultimate roofing materials. Welsh roof slate is natures weatherproofing agent formed of centuries of compression prior to extraction.

• Cwt-Y-Bugail Slates: Read the ultimate guide here. 
• Penrhyn roof slates: This article provides a summary of this alate. 
• Ffestiniog roofing slate: Read more about this roofing material. 

British Roof Slates 

• Burlington roof slates: Aesthetically beautiful and highly durable.
• Wetmorland roof slates: Arguably one of the finest roofing materials available.

Stone Roof Slates 

The heavyweight of roofing materials, stone roof slates are widely used in certain locations but the practice of making new versions is becoming increasingly scarce.

Slate Quarries 

Slates quarries are fascinating places, steep in history, the provenance of a range of roofing and building materials can be traced back to when they first became operations.

There are three main Welsh Slate Quarries, Penrhyn, Ffestiniog, and Cwt-y-Bugail.

Demand for new Welsh Slate is currently high, and the main quarries struggle to maintain production to meet demand. As such, if you are considering a roofing project in new Welsh slates, then we advise advance planning and sourcing of slates to ensure timely delivery.

At GNR, through our network of trusted suppliers, we will assist all clients with sourcing and purchasing Welsh Slates for their project well in advance.

Further, we are happy to take delivery and store the slates on your behalf to ensure timely delivery to site once work is underway.

Spanish slates 

Spanish roofing slates offer a cost effective alternative to new Welsh roof slates.

At circa half the cost in terms of raw materials, they have their place for certain project types where budget constraints exist.

At GNR, we have taken time to carefully source what we believe are the best versions of Spanish slates available, owing to their consistency of colour and low pyrite (iron ore) versus others available.

There are a plethora of roof slates to choose from when considering carrying out a project.

However, there are few that compare to the aesthetic beauty and function. of a Welsh Slate. 

Welsh slate is known for its durability, quality, and aesthetic appeal. The three main variants—Penrhyn, Cwt-y-Bugail, and Ffestiniog—each have distinct characteristics:

Penrhyn Slate

• Color: Rich purple (sometimes called ‘Heather Blue’).
• Source: Penrhyn Quarry, Bethesda, North Wales.
• Features: Highly durable, smooth texture, and a distinctive deep hue that weathers beautifully. It is widely used for roofing, cladding, and decorative applications.

Cwt-y-Bugail Slate

• Color: Dark blue-grey.
• Source: Cwt-y-Bugail Quarry, near Blaenau Ffestiniog.
• Features: Fine-grained and very strong, offering a refined, elegant appearance. It is commonly used in heritage and premium roofing projects.

Ffestiniog Slate

• Color: Medium to dark grey.
• Source: Quarries in the Blaenau Ffestiniog area.
• Features: Extremely durable and weather-resistant with a slightly textured surface. Traditionally used in both roofing and architectural projects.

Key Differences

• Color: Penrhyn is purple, Cwt-y-Bugail is blue-grey, and Ffestiniog is dark grey.
• Grain & Texture: Cwt-y-Bugail is fine-grained, Penrhyn has a smooth finish, and Ffestiniog has a slight texture.
• Use Cases: While all are premium-quality roofing materials, Penrhyn is often chosen for its striking color, Cwt-y-Bugail for its elegant finish, and Ffestiniog for its historic and traditional appeal.

All three are renowned for their longevity and resistance to weathering, making them some of the finest roofing slates in the world.

Alternatives to Welsh Slate

Although it would be ideal if every roofing project could be undertaken using Welsh slate, the costs are sometimes prohibitive. 

If you are considering an alternative, there is not much that compares. 

However, at GNR, we have spent over 40 years in the roofing industry and carefully select all of our materials. 

Spanish Roof Slate 

At GNR, we offer a range of Spanish roof slates, which vary based upon availability. 

Our go to Spanish Slate, for residential and commercial roofing projects is a Lousaval LV11 or LV15. 

Their uniformity of colour, texture, and low pyrite content make them a cost effective alternative to Welsh Slates. The price difference between Welsh and Spanish Slates is considerably. Spanish Slates are circa half the price of an equivalent sized Welsh alternative. 

Random Widths, Diminishing Courses 

At GNR, we can also offer comprehensive services using random width and diminishing courses in slates such as Westmorland, Burlington, Vermont, and more. 

Westmorland Slates are available from both Honister and Broughton Moor Slate mines in a new format from 20″ – 9″ in random widths, with 24″ slates being available from Broughton Moor. 

Westmorland, or Burlington Green roof slates, adorn some of the countries finest buildings, and are highly durable for use as a roof covering and offer a unique aesthetic. 

More information is available via our Westmorland Slate page.