Riverstone Phyllite

Riverstone Phyllite: Suitable For A Range Of Applications

SSQ's Riverstone phyllite is harder and stronger than natural slate, making it an ideal choice for roofing projects around the world. It also boasts remarkable versatility, rendering it a great solution for a range of applications such as flooring, cladding, and even in the construction of swimming pools.

Features & Benefits:
• Colour : Grey
• Material : Phyllite
• Extremely weather resistant
• Sourced from Argentina
• Non-combustible
• Denser than most stones
• 100-year weather tightness guarantee

• ASTM C406
• BS EN 12326 – W1-T1-S1

Download the Riverstone brochure Watch video

Rarer than gold

On the plains of South America, between the Pampas and the Andes, we found phyllite – the slate-like architectural stone that’s gone on to become one of the world’s most sought-after roofing, cladding and flooring materials.

It’s extremely rare. But at SSQ, we’re proud owners of one of the world’s few phyllite quarries in La Repressa, Argentina - and it’s from here that we source Riverstone.

Penyland Barn
Riverstone cladding low wall

Riverstone: sleek, stylish – and extremely versatile

Whether it’s as roofing, stone cladding or flooring, Riverstone graces domestic and commercial buildings all around the world, from America, to Australia, to thousands of homes and businesses throughout the UK and Ireland.

Due to its premium quality, Riverstone is also one of the few imported slates that has been accepted by Heritage England and Heritage Scotland as an alternative material to use on grade II listed buildings, when a native version is not available. This makes it the perfect choice when you have a heritage or conservation area project where you want the beauty and quality that slate provides, but local planning and building regulations are in place.

Contact us

Why Choose Riverstone?

Riverstone boasts exceptional durability and water absorption.

Assessed to the US testing standard ASTM C406, Riverstone was awarded an S1 rating, indicating it will last a minimum of 75 years.

What’s more, it achieves the highest possible classification in BS EN 12326 – W1-T1-S1.

Contact us
University of Bristol

Guaranteed for a century

On Ultra-grade Riverstone – some of the thinnest phyllite you can find anywhere that still holds its strength – we offer the option for a 100-year weathertightness guarantee, and the opportunity to choose an Insurance Backed guarantee covering all materials, workmanship, and, in certain cases, the design, too.

View our guarantees

Riverstone phyllite unique characteristics

Riverstone phyllite is both extremely durable and provides a stunning aesthetic finish. Roofing slates made from Argentinian Riverstone provide outstanding weather resistance, will not fade or become discoloured and are the perfect alternative for use in heritage property renovations.

When you choose Riverstone for your next roofing project, you can expect:

  • A stronger, harder, and denser material than natural slate
  • Attractive grey colour with unique phyllitic sheen
  • 100% natural material
  • Compatibility with specialist roofing and cladding architectural projects
  • 100-year weather tightness guarantee
Contact us
A Riverstone Ridge roof.

Riverstone Ridges

For decades, otherwise pristine slate roofs were ruined by the use of ridges that clashed with their natural aesthetics.
This was because it wasn’t yet possible to make ridges out of natural slate, and so installers were forced to use differently coloured man-made materials instead.

The Riverstone Slate Ridge system has changed all that. Using real slates chemically and mechanically bonded to a GRP waterproof layer, they deliver both outstanding aesthetics and outstanding performance.

  • Invisible RidgeFix method permanently fixes ridges into position
  • No roll-out ridge fixing kit required, saving materials and labour
  • Pre-drilled and complete with two stainless steel retaining screws
  • Easily cut and drilled on site to different requirements
  • Includes ridge/hop tiles, block ends, hip ends and ridge caps
Contact us

Frequently asked questions

What is the most expensive type of slate?

Natural slate is typically the most expensive type of slate because it is the most durable and long-lasting option available. Natural slate is made from thin shingles of natural metamorphic stone, which are incredibly dense and heavy. The production process for natural slate is also more time-consuming and requires specialised skills and equipment.

This makes the cost of natural slate higher compared to other types of slate. However, despite the higher cost, natural slate is an attractive option for many homeowners due to its exceptional durability, resistance to mould and fading, as well as its eco-friendly properties.

What is the best thickness for slate?

The best thickness for slate varies depending on the intended use and the quarry producing it. However, slate quarries typically aim to split slate at the thinnest possible thickness, usually between 4-6mm, while ensuring it retains the strength required for its purpose.

Contact us
Priory C.I.W School

  • Discuss Your Project
  • Request a Sample
  • Booking a CPD
  • Resources
  • Discuss Your Project

    Discuss Your Project

    Just fill in the form below, and a member of our experienced team will be in touch. Please feel free to give as much detail as you need, and include any design or technical questions you have.


    Request a Sample

    Request a Sample

    The best way of judging the quality of slate and phyllite is to hold it in your hands, and examine it in detail for yourself.
    If you’d like a sample of any of the products we provide, don’t hesitate to fill in the form below.

    Check which samples you would like to receive:

    Booking a CPD

    Book a CPD

    At SSQ, we love sharing our decades of natural slate expertise with architects, and our CPDs are always extremely popular.
    On our RIBA-approved Why Specify Slate CPD, you’ll learn about:

    • How to guarantee a perfect slate roof
    • The secret to specifying
    • Unusual roof designs
    • How to avoid specifying defective slate
    • The difference between CE tested and true quality slate
    • The legal requirements when it comes to specifying slate
    • How to specify random coursed roofing slates
    • The difference between hook and nail fixing
    • The environmental benefits of natural slate
    • Specifying heritage roofing slates

    … and a whole lot more.

    If you’re interested in booking a place on our next CPD, simply fill in this form.


    SSQ Professional Resource Centre

    When you work with SSQ, you get so much more than world-class slate and architectural stone.
    Over the last forty years, we’ve built up a huge amount of expertise covering natural slate, roofing, geology, specifications and so much more – and you can benefit from that, along with case studies, CAD drawings, technical PDFS and a wealth of other support, on our Professional Resources centre.

    Get free access
    Riverstone ridge roof
    UKCA Logo
    New NF logo
    CE logo
    LPOC Logo
    SPAB supporter
    CPD RIBA logo
    nfrc logo
    NBS Partner Logo Full
    GLDA- Corporate Membership Logo
    CORC logo
    CFS CO2 Neutral Org Logo
    BRE verified Logo
    Barbour Product Search Logo


    It is a very attractive development and we needed something equally attractive and of equally high quality for the roofing material. SSQ Del Carmen slate is top quality, and we liked the colour and texture. What’s more, it is very good value. I’d have no hesitation choosing it again.

    Mr Keith Wills, Clancy's Building Manager


    We put forward Riverstone as a cost-effective, yet high quality alternative to Welsh Slate, and it was accepted on that basis. The refurbishment work has now been completed and both the owners and ourselves are very happy with the result.

    Keith Hicks Architect at Pave Hall


    It was an absolute pleasure to meet you today, and I just wanted to take a moment to thank you for your time and a wonderfully informative CPD.

    The whole team really enjoyed it, and you definitely conveyed your passion and knowledge of your products!

    I would say I will keep SSQ in mind for future projects, but they always have been. However, I have definitely left with a need to utilise more slate in my design work!

    Michael Clifton BSc ACIAT - Oakbridge Bespoke Homes Ltd


    Working in a conservation area brings a special responsibility. SSQ Riverstone slate fits perfectly, its tone and texture blending seamlessly with its surroundings.

    Joan Kinane, Architect


    The choice of SSQ Del Carmen was made easier after confirmation that it had gained approval for use in the Welsh National Parks as an alternative to indigenous materials. We were also pleased with the level of technical, design and on-site support we received from SSQ.

    The Hafod Renewal Office


    Everyone liked Sarria: the client was delighted with its appearance and its consistency made it easy to cut and lay.

    Gary Lambert, Complete Roofing Contractors


    With the roofs being such a visible feature, the choice of roofing slate was a significant decision. We involved the roofing contractor at an early stage in the selection process and they recommended SSQ’s Del Carmen Blue-black slates. Although it’s not an indigenous slate, it is an excellent match for the originals and, having used Spanish slate on other projects, we know the quality is there.

    Richard Thorpe, Ridge and Partners LLP


    With so many ‘interested parties’ the local planners set their minds on a natural slate roof at a very early stage of the project and, from this starting point, we needed something that would satisfy a number of technical and aesthetic requirements – SSQ Domiz blue-grey, was the one chosen for use to compliment the local ‘Shere Green’ colour.

    Ben Hunt, Total Project Integration


    The choice of slates was made easier due to the quality of product you provide and the support of Gary Firth throughout the process – which I much appreciate. Gary is a good ambassador for your company.

    Pat Murray, Senior Project Engineer, Alvance Group


    We specified SSQ First Domiz Blue-grey roofing slate for both technical and aesthetic reasons:its strength and quality gives the performance needed and its cold, hard, colour provides a dramatic foil to the rich warmth of the western red cedar walls.

    Mark Webber, Architect, Nichols Brown Webber


    SSQ Matacouta slate was chosen as the most sympathetic option. Its consistency and competitive price make it a clear winner over indigenous slates.

    Historic Scotland


    Being both high quality and cost-effective, Matacouta slate from SSQ is proving very popular with specifiers and contractors alike for refurbishment as well as for new build projects.

    Mr Roy Clark, Baxter Clark and Paul

    map of the world

    Case Study

    In with the new: SSQ’s Del Carmen restores Southampton University library

    Read more View all case studies

    Case Study

    Millbridge Primary School

    Read more View all case studies

    Case Study

    Christ’s College

    Read more View all case studies

    Case Study

    Kresen Kernow

    Read more View all case studies

    Case Study

    Broad Meadow

    Read more View all case studies

    Sign up to our newsletter

    Subscribe to our newsletter to keep up to date with the latest news and offers.