Is My Roof Slate or Concrete Tile? How to Tell on a Liverpool Property (With Photos)

By Chris, owner of Everlast Roofing North West (20+ years on Merseyside roofs) · About Everlast Roofing · Last updated 2026-06-11

A first-time buyer in Aigburth rang me last spring. He had a survey flagging ‘roof material at end of life, replacement recommended’. He had been quoted twelve grand for a re-roof on the basis the surveyor had assumed the roof was natural Welsh slate. I went round, looked from the pavement, then up the ladder. Concrete interlocking tile, fitted somewhere in the 1980s, with one slipped tile above the bay and a perished mortar fillet round the chimney. The roof had another twenty-five years in it. The fix was three hundred quid. The twelve-grand re-roof was based on the wrong material identification.

It happens more than you would think on Liverpool houses. The age, the streetscape and the survey wording often make people assume slate when it is tile, or tile when it is slate. So before you accept any quote, before you ring around, before you even worry about cost, three minutes from the pavement with this guide will tell you what your roof actually is. The repair conversation gets a lot easier from there.

The five-second pavement test

Stand on the pavement opposite your Liverpool property, look up at the roof, and answer two questions.

One, what does the bottom row look like? Specifically, the edge of the lowest row of roof material where it overhangs the gutter. A knife-edge, thin, flat, with no profile, is slate. A thicker edge with a curve, a step, or a visible shape is tile. The difference is visible from the pavement on a clear day.

Two, are the rows the same size, or do they get smaller toward the top of the roof? Slate is usually laid in graded courses, meaning the slates at the bottom are bigger and the ones at the top are smaller. The visible courses get tighter as you look up. Tile is usually laid in identical courses all the way up. Identical courses point to tile. Graded courses point to slate.

If you cannot tell from the pavement (overhanging tree, dirty roof, low light), the next step is a phone with a zoom. Take three photos: the whole roof, the area at the gutter, the area at the ridge. The zoom usually settles the question. The third option is to find a slate or tile that has slipped off and landed in the garden over the years (most Liverpool homes have one) and inspect it directly. Slate weighs much less than tile per piece, has a clean break, and is easy to snap by hand. Concrete tile is heavy, gritty, and cannot be snapped by hand. Clay tile is brittle, breaks with a sharp edge, often has a maker’s stamp on the back.

What natural Welsh slate looks like on a Liverpool Victorian terrace

Most Liverpool terraced houses built between 1860 and 1910 (in postcodes L4, L5, L7, L8, L17, L18, L20, parts of L19 and L23) were roofed in natural Welsh slate. It is the default for the era and the city.

Visually it is thin (about 5 to 8mm), flat, with no profile, in a colour that ranges from dark grey through blue-grey to a slightly purplish-grey depending on which Welsh quarry it came from (Penrhyn, Dinorwig, Ffestiniog). Penrhyn slate is the deepest near-black grey, Dinorwig is a more open grey, Ffestiniog is a slightly violet-grey. All three are common on Liverpool roofs.

Slates are sized in inches (English merchant tradition) rather than millimetres: 20 by 10, 18 by 9, 16 by 8 are common sizes. They are nailed (originally with copper nails, sometimes with steel which is what causes nail sickness later) onto softwood laths over the rafters. Many Liverpool pre-1930 slate roofs have no felt underneath. That is normal and not dangerous, slate has done its job for a hundred years without felt on thousands of Liverpool roofs.

A natural slate roof on a Liverpool Victorian terrace, properly maintained, has an honest lifespan of 80 to 120 years. The slates themselves often outlast everything else on the roof: the nails go first (rust through), the lead flashings go second (weather out at about 60 to 80 years), the mortar fillets and ridges go third. A re-roof on a 100-year-old Liverpool slate roof is often a strip-and-re-fix of the existing slates onto new battens and felt, rather than a full new-slate job. Reclaimed natural Welsh slate is also common for conservation-area work.

What concrete tile looks like on a Liverpool 1930s semi

Most Liverpool 1930s semis (in Woolton, Childwall, Allerton, parts of Crosby and Aintree) were built with clay tile originally, but a large share of them were re-roofed in the 1970s and 1980s with concrete interlocking tile, which became the cheapest mass-market roof material at the time. So a 1930s Liverpool semi today is usually concrete tile, even though it was clay tile when built. The same applies to most Liverpool 60s and 70s semis (Maghull, Norris Green, parts of Huyton).

Visually, concrete interlocking tile is thick (about 15 to 20mm), profiled (a curve, an S-shape, or a step that interlocks with the next tile), in a colour that ranges from grey-beige through brown to a near-red depending on the manufacturer (Marley, Redland, Sandtoft are the main UK suppliers). Some Liverpool 1980s re-roofs used flat ‘concrete slates’, a flat profile imitation of natural slate, also concrete material, much thicker than real slate.

Tiles are hung on battens (with no nails for most of the tile, only nailed at the eaves and verges), over breathable underlay membrane (modern) or bituminous felt (1970s and 1980s installs). The bituminous felt is usually what fails first, often within thirty years, and leads to leaks that look like ‘the roof has failed’ when actually only the underlay has.

A concrete tile roof on a Liverpool 1930s semi has an honest lifespan of 40 to 60 years for the tiles, but the underlying felt is usually the determining factor and is more like 25 to 40 years. The roofer’s job is often to identify whether the tiles are sound and only the felt needs replacing (which is a strip and re-fix of the existing tiles, much cheaper than full re-tile).

What clay tile and the rarer materials look like

Clay tile, the original material on most Liverpool 1930s semis before the concrete re-roof wave, is less common today on the street but still found on heritage and listed properties around Toxteth (L8), Sefton Park (L17), the Georgian quarter (L1, L3), and Cheshire villages around Chester.

Visually, clay tile is reddish-brown or orange (Marseilles pattern), rougher in texture than concrete, often with visible mineral spots or burn marks from the kiln. Older hand-made clay tiles have irregular edges and small variations in colour. Mass-produced 20th-century clay tiles are uniform. Both are thinner than concrete tile and lighter to handle.

On a Liverpool roof, clay tile usually means either an original 1900-1930 install or a heritage restoration in a conservation area. Either way, conservation rules often require like-for-like replacement (you cannot put concrete tile on a clay-tile listed building without planning consent). Liverpool City Council planning publishes the conservation area boundaries online.

Other materials you may have in Liverpool. Spanish slate (cheaper natural slate alternative, common on 1990s and 2000s re-roofs, visually similar to Welsh slate but less consistent in colour). Reclaimed slate (used in heritage work). Metal roofing (very rare on Liverpool residential, occasionally on commercial). Asphalt shingles (American product, virtually absent from Liverpool residential). GRP fibreglass (flat roof material, never used on pitched residential roofs in Liverpool).

Why it matters: repair cost, lifespan and conservation rules

The reason ‘is my roof slate or tile’ is one of the most-Googled UK roofing questions is that the answer changes everything about the repair.

Cost. A slipped slate repair on a Liverpool Victorian terrace is typically £180 to £400. A slipped concrete tile repair on a 1930s semi is typically £150 to £350 (cheaper materials, easier to source matching tiles, faster to fix). A clay tile repair on a conservation property is typically £300 to £700 because the matching tiles are harder to find.

Replacement materials. If your roof is natural Welsh slate, the replacement slate should be natural Welsh slate (or reclaimed Welsh slate for conservation work). Mixing Spanish slate or concrete slate onto a natural Welsh roof looks wrong from the street and may breach conservation rules. If your roof is concrete tile, the replacement tile should be the same pattern (Marley Modern, Redland Renown, Sandtoft Calderdale and so on), which means the roofer needs to identify the maker’s mark on the underside. A full re-roof is the place where this matters most: the wrong material costs the same money and lasts half as long.

Lifespan and re-roof timing. A natural Welsh slate roof on a Liverpool terrace can often have its lifespan extended by 30 to 50 years through a strip-and-re-fix (relaying the existing slates onto new battens and felt). A concrete tile roof generally cannot, because the tiles themselves are typically the limiting factor and are not worth re-using once stripped. Knowing which you have is what tells you whether your next major roofing decision in ten years is a £4,000 strip-and-re-fix or a £9,000 full new-tile.

Conservation rules. Listed buildings and properties in Liverpool conservation areas (parts of L1, L3, L8, L17) typically have planning conditions that require like-for-like roof material replacement. Putting concrete tile on a clay-tile listed property without consent can lead to enforcement action and forced replacement at your cost. The roof inspection we provide includes material identification in the written report, which is exactly what your planning paperwork or insurance claim needs.

• Stand on the pavement, look at the bottom row of the roof at the gutter. Thin knife-edge = slate. Thick curved or stepped edge = tile.
• Check the colour. Dark grey or blue-grey = slate. Beige or warm grey = concrete tile. Reddish-brown = clay tile.
• Look for graded courses (getting smaller toward the top). Graded = slate. Identical courses = tile.
• If a slate or tile has fallen off into the garden, pick it up. Thin and light = slate. Thick and heavy = tile.
• Take three phone photos: whole roof, gutter line close-up, ridge close-up. Zoom in. The zoom usually settles it.
• On a 1930s semi, do not assume the original material is still on the roof. Many were re-roofed in concrete tile in the 1970s and 1980s.
• On a listed or conservation-area property, get the material formally identified before any quote, the planning rules depend on it.

Frequently asked questions

For more local roofing advice, browse the Everlast Roofing blog or call Chris on 07933 828 045.