Roofing for London Homes: Tiles, Slates, and How to Choose the Right Covering for Your Roof

The roof covering of a London home — the tiles, slates, and associated leadwork that keep the structure watertight — is one of the most important and longest-lasting elements of the building. When a roof works well it is invisible; when it fails, the consequences extend to every room below.

London's residential roofscape is dominated by the pitched roofs of Victorian and Edwardian terrace and semi-detached housing: typically slate or plain clay tile on the main roof slopes, with leadwork in valleys, hips, ridges, and abutments. Understanding the options when re-roofing or undertaking major roof works helps homeowners and their contractors make decisions that will last for decades.

Natural Slate

Welsh and Spanish natural slate are the most historically authentic covering for Victorian terrace housing in London, which was originally roofed in Welsh blue-grey slate. Natural slate is:

• Durable: good quality Welsh slate (from the Penrhyn or Ffestiniog quarries) can last 100+ years. Spanish slate (from Galicia) is also high quality and more readily available, with a typical lifespan of 50–80 years.
• Thin and lightweight: at 8–14 mm thickness, natural slate is lighter than most tile alternatives, which is significant when re-roofing properties whose original structure was designed for slate loads.
• Visually appropriate for period properties: conservation areas often specify natural slate for re-roofing to preserve the local character.

The disadvantages of natural slate are cost (it is the most expensive roofing material on a per-m² basis) and the need for skilled slating to avoid failures at nail holes and fixings. Poor slating with undersize fixings or inadequate head laps is the most common cause of slate roof failures.

Fibre Cement Slate

Artificial slates made from fibre cement (Cembrit, Marley Eternit, Redland Cambrian, and others) are produced to simulate the appearance of natural slate at lower cost. They are manufactured to precise dimensions (unlike natural slate which varies) and are consistent in thickness and weight.

Fibre cement slates have lifespans of 30–50 years. They are more consistent to lay than natural slate and are the most common re-roofing material for Victorian and Edwardian terrace houses in London where original slate has failed.

In conservation areas, planning authorities may require natural slate rather than fibre cement alternatives where the roof is visible from the highway, but for rear slopes and many inner terrace properties, fibre cement slate is acceptable.

Plain Clay Tiles

Traditional plain clay tiles (also called plain peg tiles) were widely used in the lower-slope areas of London Victorian houses — particularly on rear additions and bay roofs where pitches were shallower than the main roof. They have a handmade appearance with slight variation in colour and texture that gives a warm, characterful finish.

Clay plain tiles are durable (50–100+ years for good quality tiles) and are specified for conservation area re-roofing where clay tile was the original material.

Concrete Tiles

Concrete interlocking tiles (from manufacturers such as Marley, Redland, and Monier) are the most widely used pitched roof covering in UK new build construction. They are heavier than slate or clay plain tiles but are durable (40–60 years) and cheaper on a per-m² basis than natural materials.

Concrete tiles were widely used in London roof replacements during the post-war decades and are found on many 1960s–1990s properties and extensions. On older Victorian properties, the switch from lightweight slate to heavy concrete tiles has in some cases imposed additional loads on roof structures not designed for them — a consideration when assessing an existing roof.

Pantiles and Interlocking Clay Tiles

Used less commonly in London (more common in East Anglia and the Midlands) but occasionally specified for contemporary extensions and new build.

Beneath all pitched roof coverings is a secondary waterproofing layer: the roofing underlay (felt or modern breather membrane) on the rafters, with tiling battens fixed over the underlay to support the tile or slate courses.

Original Victorian roofs used bitumen-based roofing felt or in some cases torched fibre felt. These felt layers have a service life of approximately 40–60 years and frequently fail before the slates above. A common symptom of failed underlay is wind-blown or frost-lifted slates without obvious structural damage to the slates themselves — the flexibility of the underlay has allowed the batten to move under the fixing nails.

When re-roofing a Victorian property, the standard approach is to strip all the existing slates or tiles, remove and replace the felt and battens, inspect and repair or replace any rotten or damaged rafters, and relay the new covering. The cost of the additional felt and batten replacement relative to the cost of a complete strip and relay is small, and it is poor practice (and risks Building Control issues) to simply relay new slates on old deteriorated underlay and battens.

Modern breathable roofing membranes (such as Tyvek or equivalent) allow water vapour to pass from the roof space to the outside while preventing liquid water entry — an improvement over traditional bitumen felt that was not vapour-permeable.

The junctions between roof slopes and walls (abutments), the intersections between two roof slopes (valleys and hips), and the ridgeline at the top of the roof all require specific detailing to prevent water ingress at these vulnerable points:

• Valleys: the internal angle between two roof slopes where water runoff concentrates. Traditional London roofs use lead valleys (Code 4 or Code 5 lead); modern alternatives include GRP valley liners or deep-section valley tiles.
• Abutment flashings: where a roof meets a wall (chimney, rear wall, side wall), lead stepped flashings are dressed into the mortar joints of the masonry to form a watertight seal. These are commonly a point of failure in older roofs where the mortar joints have deteriorated.
• Hip capping: the external junction between two roof slopes. Can be covered with half-round ridge tiles, hip tiles, or lead.
• Ridge: the apex of the roof, typically covered with clay or concrete segmental ridge tiles bedded in mortar.

Lead (to BS EN 12588) is the traditional and highest-quality material for all of these details. Code 4 lead (1.8 mm thickness) is the minimum for horizontal surfaces; Code 5 (2.24 mm) for aprons, stepped flashings, and more exposed positions.

Re-roofing of more than 50% of a pitched roof area must achieve Part L compliance for the thermal envelope — this typically means installing appropriate insulation at the same time as the re-roofing works if the roof was not previously insulated to current standards. Building Control notification may be required.

Indicative costs for re-roofing a typical 3-bedroom London terrace house (2025):

• Fibre cement slate re-roof (strip, new felt and battens, relay): £6,000–£12,000
• Natural Welsh slate re-roof: £10,000–£20,000+
• Clay plain tile re-roof: £8,000–£16,000
• Including lead valley and chimney flashing renewal: add £800–£2,500

rcbGroup manages roof works — from minor repairs to complete re-roofing — as part of our London residential project portfolio. We advise on appropriate materials for the building type and planning context, coordinate leadwork and specialist roofing, and manage Building Regulations compliance where applicable.

Contact our team to discuss roofing requirements for your London property.