Reclaimed Welsh Slate: Why It’s One of the Best Roofing Materials in the UK

Ross Reclamation – One of the UK’s Leading Suppliers of Welsh Slate

At Ross Reclamation, we are proud to be one of the top suppliers of reclaimed Welsh slate in the UK. From historic buildings to modern renovations, Welsh slate has been trusted for centuries as one of the most durable and beautiful roofing materials available.

Builders, roofers, developers and homeowners from across the UK source slate from our yard. Whether you are repairing a heritage property, replacing a roof, or matching existing slates for an extension, reclaimed Welsh slate is often the best solution. View our current stock of reclaimed Welsh slate here.

The History of Welsh Slate

Welsh slate has been quarried for over 500 years, with the slate quarries of North Wales once producing roofing material that was exported all over the world.

Famous quarries such as Penrhyn, Dinorwic and Ffestiniog helped build some of Britain’s most iconic roofs, from Victorian terraces to historic churches and country houses.

Penrhyn Slate Quarry, in 1852

The reason Welsh slate became so sought-after is simple: quality. The dense structure of Welsh slate makes it extremely strong, weather-resistant and long-lasting.

Many roofs installed over 100 years ago are still performing perfectly today.

Why Reclaimed Welsh Slate Is Often Better Than New

One of the biggest advantages of reclaimed slate is that it has already proven itself.

Slates that have survived decades on a roof are known to be strong and durable. When carefully removed, sorted and graded, they can be reused for many more decades.

Benefits of reclaimed slate include:

• Proven long lifespan

• Natural weathering and colour variation

• Ideal for matching existing roofs

• Perfect for period properties and conservation work

• More environmentally friendly than new materials

For repairs and heritage projects, reclaimed slate is often the only way to properly match an existing roof.

A Sustainable Roofing Choice

Reclaimed slate is also one of the most sustainable roofing materials available. Natural slate is an extremely durable material with very low water absorption, making it highly resistant to frost damage and capable of lasting well over a century.

Reusing slate means:

• Less waste going to landfill

• Less quarrying of natural resources

• Reduced carbon footprint compared with new slate production

By choosing reclaimed slate, you are helping preserve both historic materials and the environment.

Traditional Welsh Slate Sizes and Names

Slate Name	Size (Inches)	Size (mm approx.)	Typical Use
Imperial	30 × 15	762 × 381	Large roofs, churches, historic buildings
Princess	28 × 14	711 × 356	Large heritage roofs
Prince	24 × 14	610 × 356	Large traditional roofs and diminishing courses
Duchess	24 × 12	610 × 305	One of the most common roofing sizes
Countess	20 × 10	508 × 254	Traditional domestic roofing
Viscountess	18 × 9	457 × 229	Small domestic roofs
Marchioness	16 × 8	406 × 203	Often used higher up roofs
Lady	14 × 7	356 × 178	Small courses / repairs
Queen	12 × 6	305 × 152	Top courses and detailing

Slate Name	Size (Inches)	Size (mm approx.)	Typical Use
Imperial	30 × 15	762 × 381	Large roofs, churches, historic buildings
Princess	28 × 14	711 × 356	Large heritage roofs
Prince	24 × 14	610 × 356	Large traditional roofs and diminishing courses
Duchess	24 × 12	610 × 305	One of the most common roofing sizes
Countess	20 × 10	508 × 254	Traditional domestic roofing
Viscountess	18 × 9	457 × 229	Small domestic roofs
Marchioness	16 × 8	406 × 203	Often used higher up roofs
Lady	14 × 7	356 × 178	Small courses / repairs
Queen	12 × 6	305 × 152	Top courses and detailing

Why Welsh Slate Has Royal Names

Welsh slate sizes traditionally follow a royal naming system, which originated in the 19th century when the Welsh slate industry was exporting roofing slate all over the world.

These names helped merchants and builders quickly identify sizes when ordering slate from the quarries.

Today, roofers still use these names when discussing slate sizes — especially when working on period properties and traditional roofs.

Diminishing Courses in Traditional Slate Roofs

Many historic roofs were laid using diminishing courses, where larger slates are installed at the bottom of the roof and gradually reduce in size towards the ridge.

A typical sequence might be:

Imperial → Prince → Duchess → Countess → Viscountess → Marchioness → Lady → Queen

This technique:

• Improves water runoff

• Reduces weight higher up the roof

• Creates the classic traditional appearance seen on many historic buildings.

Matching Slate for Repairs

One of the most common reasons customers visit Ross Reclamation is to match slate sizes for roof repairs.

If you bring a sample slate to the yard, we can usually help identify:

• The slate size

• The closest reclaimed match

• The quantity required for repairs or extensions.

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Because reclaimed Welsh slate has already lasted decades on a roof, it remains one of the most reliable roofing materials available.

Who Uses Reclaimed Welsh Slate?

Our reclaimed slates are used by:

• Roofers

• Builders

• Property developers

• Heritage restoration specialists

• Architects

• Homeowners restoring period properties

We regularly supply slate for roof repairs, full re-roofs, listed buildings, barn conversions and extensions.

Why Builders Choose Ross Reclamation

Ross Reclamation has built a strong reputation for supplying high-quality reclaimed building materials since 2020. At Ross Reclamation we regularly stock a wide range of reclaimed Welsh slate in many traditional sizes, allowing builders and roofers to match existing roofs as closely as possible.

Customers choose us because we offer:

• Large stock of reclaimed materials

• Quality sorted Welsh slate

• Knowledgeable advice

• Competitive prices

• Easy yard access for loading and collection

Our yard in Ross-on-Wye, Herefordshire is a hidden gem packed with architectural salvage, reclaimed stone, bricks, timber and roofing materials.

Experience You Can Trust

At Ross Reclamation, Welsh slate isn’t just another product — it’s something that comes with decades of knowledge and experience. Based in Ross-on-Wye, Herefordshire, Ross Reclamation supplies reclaimed Welsh slate to builders, roofers and homeowners across Herefordshire, Gloucestershire, Monmouthshire and the wider UK.   View our current stock of reclaimed Welsh slate here.

Michael, who owns the yard, has spent many years working with reclaimed roofing materials and understands the quality and character of traditional Welsh slate. His knowledge was passed down from his father John, who worked with slate before him, giving the business a genuine connection to the craft and tradition of reclaimed materials.

Every batch of slate that comes through the yard is personally hand-sorted by Michael. This careful process ensures the slates are suitable for reuse and allows builders and roofers to select the sizes and quantities they need for their projects.

Sorting slate properly is skilled work. Each piece is checked for quality, thickness and condition so that only good, usable slate goes back onto roofs.

It’s this attention to detail and experience that keeps customers returning to Ross Reclamation when they need reliable reclaimed Welsh slate.

How to Identify Welsh Slate on Your Roof

If you're repairing an older roof, it’s often important to identify the type of slate already in place. Welsh slate has several characteristics that make it recognisable.

1. Colour

Welsh slate is usually a deep blue-grey colour, although some pieces appear almost purple or dark charcoal depending on the quarry and how the slate has weathered over time.

Unlike many imported slates, Welsh slate tends to have consistent natural colouring rather than strong colour variation.

2. Strength and Density

Welsh slate is known for being extremely dense and durable. When handled, it often feels heavier and stronger than many modern imported roofing slates.

A well-made Welsh slate can last over 100 years on a roof.

3. Smooth Texture

The surface of Welsh slate is typically very smooth and fine-grained, giving roofs a clean and uniform appearance.

This fine texture is one of the reasons Welsh slate was historically considered one of the highest quality roofing materials in the world.

4. Traditional Slate Sizes

Many older roofs use the traditional named slate sizes such as Duchess, Countess or Viscountess. Identifying the slate size can help determine whether your roof uses Welsh slate.

5. Bring a Sample

If you’re unsure what slate is on your roof, the easiest solution is to bring a sample slate to Ross Reclamation.

With years of experience handling reclaimed roofing materials, we can usually help identify:

• The slate size

• The closest reclaimed match

• The quantity needed for repairs.

Matching slate properly helps maintain the character and integrity of traditional roofs, especially on older or heritage properties.

How Many Welsh Slates Are Needed Per Square Metre?

One of the most common questions when planning a slate roof is how many slates are needed per square metre. The answer depends on several factors, including the size of the slate, the headlap, and the roof pitch.

The number of Welsh slates per square metre typically ranges from 8 slates per m² for large Imperial slates to around 36 slates per m² for small Queen slates.

As a general guide, larger slates require fewer pieces per square metre, while smaller slates require more.

Below is a typical guide for traditional Welsh slate sizes:

Slate Size	Slate Name	Approx Slates per m²
30" × 15"	Imperial	8–10
28" × 14"	Princess	9–11
24" × 14"	Prince	10–12
24" × 12"	Duchess	12–14
20" × 10"	Countess	16–18
18" × 9"	Viscountess	18–20
16" × 8"	Marchioness	22–24
14" × 7"	Lady	26–30
12" × 6"	Queen	32–36

These figures are approximate, as the exact number depends on the lap used by the roofer and the roof pitch.

Allowing for Wastage

When ordering reclaimed slate, it’s always sensible to allow extra for breakages and sorting. A common rule is to order around 10% more slate than the calculated roof area requires.

This ensures roofers have enough good slates to complete the job while maintaining a consistent finish.

Not Sure What You Need?

If you’re unsure what slate size your roof uses, the easiest option is to bring a sample slate to Ross Reclamation.

With years of experience handling reclaimed roofing materials, we can usually help identify the slate size and advise on the quantity required for your project.

Slate Roofing Terminology Explained

When working with traditional slate roofing, a number of specific terms are used to describe the parts of a slate and how slates are laid on a roof. Understanding this terminology can make it much easier to discuss repairs, measure existing slates, and plan roofing projects using reclaimed Welsh slate.

Below are some of the key terms commonly used by roofers when working with slate roofs.

Slate Terminology Diagram, with thanks to Detail Library

Head – The upper edge of the slate when it is laid on the roof. This part of the slate is covered by the course above.

Tail – The lower edge of the slate when laid. This is the visible edge that forms the finished surface of the roof.

Face – The upper surface of the slate once installed on the roof. This is the side exposed to the weather.

Lap (Headlap) – The amount by which the tail of a slate overlaps the head of the slate in the course below. Correct lap is essential for weatherproofing the roof.

Bond or Side Lap – The horizontal distance between the side edge of one slate and the side edge of the slate directly above it. This ensures joints are staggered and water cannot pass through vertical gaps.

Gauge – The vertical distance between the tail of one slate and the tail of the slate in the course above.

Holing Gauge – The distance between the tail of the slate and the nail hole used to fix the slate to the batten.

Batten Gauge – The spacing between the roofing battens that support the slates.

Visit Ross Reclamation

If you are looking for reclaimed Welsh slate in the UK, we would be delighted to help.   View our current stock of reclaimed Welsh slate here.

Whether you need a small quantity for repairs or larger amounts for a full roofing project, our team can help you find the right slate.

Visit the yard, give us a call, or get in touch to check current stock. You can contact Michael on 07794 411143

Ross Reclamation

Broadmeadow Industrial Estate

Ross-on-Wye

Herefordshire

HR9 7AQ

📞 Call us: 07794 411143