Slate roof explained: lifespan, cost and types

Natural slate lasts 75-100 years but costs £80-120/m². Synthetic slate lasts 40-60 years and costs £60-90/m².

How long does a slate roof last?

Natural slate lasts 75-100 years according to Which? and the National Federation of Roofing Contractors. Welsh slate from Penrhyn or Ffestiniog quarries can last 100+ years. Spanish slate lasts 60-80 years (slightly softer stone). Synthetic slate (fibre cement) lasts 40-60 years per manufacturer warranties.

Lifespan depends on slate quality and installation. Low-grade slate delaminates (layers separate) after 40-50 years. Nails rust and slates slip. Wind-driven rain gets under poorly overlapped slates. A well-installed natural slate roof can outlast the building.

Natural slate lifespan

75-100 years

Synthetic slate lifespan

40-60 years

Natural slate weight

25-30 kg/m² (needs strong rafters)

Typical cost installed

£60-120/m²

How much does a slate roof cost?

Natural slate: £80-120/m² installed. Synthetic slate: £60-90/m² installed. A typical 60m² roof costs £4,800-7,200 for natural slate or £3,600-5,400 for synthetic. These are 2026 Checkatrade averages including labour.

Welsh slate costs more than Spanish (£100-120/m² vs £80-100/m²) because it's harder and lasts longer. Reclaimed slate costs £70-100/m² (cheaper material but higher labour to sort and match).

What is the difference between natural and synthetic slate?

Natural slate is quarried stone (metamorphic rock). Synthetic slate is fibre cement (cement + cellulose fibres pressed into sheets). Natural slate is heavier (25-30 kg/m²), lasts longer (75-100 years), costs more (£80-120/m²). Synthetic slate is lighter (10-15 kg/m²), lasts 40-60 years, costs less (£60-90/m²).

Visually they're similar from ground level. Close up, natural slate has visible grain and colour variation. Synthetic slate looks more uniform. Both come in grey, blue-grey, green and plum shades.

Does my roof structure support slate?

Natural slate weighs 25-30 kg/m². Concrete tiles weigh 40-50 kg/m². Clay tiles weigh 35-45 kg/m². So slate is lighter than concrete but heavier than modern lightweight tiles (15-20 kg/m²). If your roof currently has concrete tiles, it supports slate. If it has lightweight tiles, you may need to strengthen rafters (adds £1,000-2,000).

Building Control will want to see structural calculations for a slate roof on a new build or extension. For re-roofing an existing property, a surveyor checks rafter size and spacing.

Last reviewed: 2026-05-16