The Complete Guide to Slate & Tile Roofing
Natural Slate vs Artificial Slate — The Real Differences
Natural slate and artificial (man-made or fibre cement) slate may look similar from the ground, but they are fundamentally different materials with very different characteristics, lifespans, and costs. Understanding the differences will help you make the right choice for your property.
Natural slate is a metamorphic rock, quarried in sheets and split to thickness. The finest natural slates — Welsh slate from Penrhyn (Bangor Blue) or Ffestiniog (Cwt-y-Bugail) — are among the most durable roofing materials on earth, with a proven lifespan of 150-200+ years. They are virtually non-porous, resistant to freeze-thaw cycling, and maintain their appearance indefinitely. Welsh slate carries an S1 rating under BS EN 12326 (the lowest water absorption category) and a T1 thermal cycling resistance. It is, quite simply, the finest roofing slate available anywhere.
Spanish slate (typically from quarries in the Galicia region) offers excellent value at roughly 50-65% of the cost of Welsh slate. Good-quality Spanish slate — sourced from SIGA-certified quarries with full BBA or BRE certification — can last 80-100+ years and performs admirably in the UK climate. However, quality varies enormously between quarries. Cheap, uncertified Spanish slate (often found on budget new-builds) can delaminate, rust (due to iron pyrite inclusions), and fail within 20-30 years. We only source from quarries we have personally vetted.
Artificial slate — products like SSQ Riverstone, Marley Edgemere Slate, or fibre cement slates from Cembrit and Eternit — are manufactured to look like natural slate but are made from concrete, fibre cement, or recycite composites. They are lighter, cheaper, and more uniform than natural slate, with a typical lifespan of 40-60 years. They are a perfectly respectable choice for modern properties and extensions, but they do not carry the prestige, longevity, or character of genuine natural slate. In conservation areas, artificial slates are often not accepted by the planning authority.
Clay Tiles — When Heritage Meets Performance
Clay roofing tiles have been used on British buildings for over 700 years, and they remain one of the finest roofing materials available. Modern clay tiles combine centuries-old tradition with advanced manufacturing techniques to produce a product that is beautiful, durable, and exceptionally long-lasting.
There are three main types of clay roof tile used in the UK. Plain tiles (also called flat tiles or peg tiles) are the traditional rectangular tile — approximately 265mm x 165mm — that has been used since medieval times. They are double-lapped (each point on the roof is covered by at least two tiles), which provides excellent weather protection but requires a steep pitch (minimum 35 degrees) and uses a lot of tiles — approximately 60 per square metre. Handmade plain tiles from manufacturers like Dreadnought, Sahtas, and Keymer have a beautiful, irregular texture with subtle colour variations that machine-made tiles cannot replicate. They weigh around 75 kg/m2, so the roof structure must be adequate to support them.
Interlocking clay tiles — such as the Sandtoft 20/20 or Wienerberger Actua — have a single lap with interlocking side joints, meaning fewer tiles per square metre and a lighter overall weight. They are suitable for pitches from 17.5 degrees upwards and offer a more modern appearance. They are particularly popular for extension roofs where a clay finish is desired but the structure cannot support the weight of traditional plain tiles.
Pan tiles (also called pantiles or S-tiles) are a distinctive curved profile most commonly seen in eastern England. In Berkshire, they are less common but occasionally required for heritage properties. Modern reproductions from Sandtoft and Imerys closely match the traditional profiles.
Concrete Tiles — The Modern Workhorse
Concrete interlocking tiles account for the majority of residential roofs installed in the UK over the past 50 years, and for good reason — they offer an excellent balance of durability, aesthetics, and value. Modern concrete tiles bear little resemblance to the grey, characterless products of the 1960s and 70s. Today's ranges from Marley, Redland, Forticrete, and Russell come in a wide variety of profiles, textures, and colours that can complement any property style.
The most popular concrete tile profiles we install across Berkshire include: Marley Edgemere (a slim-line, flat interlocking tile with a contemporary appearance), Marley Modern (the UK's best-selling roof tile — a bold, granular-textured interlocking tile), Redland 49 (a versatile interlocking tile with a smooth or granular finish), Redland Mini Stonewold (a smaller-format tile that replicates the appearance of natural stone slate), and Forticrete Centurion (a large-format, lightweight interlocking tile for fast, economical installation).
Concrete tiles typically last 50-60 years. They are heavier than artificial slate but lighter than clay plain tiles, making them suitable for most standard roof structures without modification. They achieve their colour through a through-body pigmentation or surface coating process — through-coloured tiles maintain their appearance better over time, while surface-coated tiles may fade somewhat after 15-20 years. All concrete tiles we install are mechanically fixed to BS 5534 using appropriate clips and nails for the wind exposure zone — which in Berkshire and the Thames Valley is typically Zone 2 or Zone 3.
Matching Existing Tiles on Repairs & Extensions
One of the most common challenges in roofing is matching the existing tiles on a property when carrying out repairs, building an extension, or replacing a damaged section. This is an area where experience and material knowledge make the difference between a seamless result and an obvious mismatch that devalues your property.
For common, currently-manufactured tiles — Marley Modern, Redland 49, Marley Ludlow Major — matching is straightforward as long as you get the colour right. New tiles will look slightly different from weathered ones initially, but they blend within 2-3 years. We always recommend installing new tiles on the less visible elevation and moving weathered tiles to the front if a close match is critical in the short term.
For discontinued tiles, matching requires detective work. We maintain a database of tile profiles and can usually identify an unknown tile from a photograph or physical sample. Sources include specialist reclamation yards (such as BJ Salvage in Berkshire and Heritage Reclamation in Surrey), salvage from demolition sites, and occasionally the manufacturer's own legacy stock. When a like-for-like match is impossible, we recommend the closest modern equivalent and discuss with you whether a full re-tile of the visible elevation is preferable to a noticeable mismatch.
For conservation areas in Windsor, Ascot, and parts of Greater London, matching existing materials is often a planning requirement, not just an aesthetic preference. We work closely with local planning officers and conservation teams to ensure our material choices meet the requirements of listed building consents and conservation area regulations.
