Roofing

Natural Slate.

Natural slate has the lowest CO₂ footprint of all roofing materials and lasts 100–150 years. Always calculate lifecycle CO₂ — cheaper materials with shorter lifespans often give a higher total footprint.

Key Figures

Carbon Footprint (GWP): 0.058 kg CO₂-eq/kg
Density: 2700 kg/m³
Expected Lifespan: 100–150+ år

What is natural slate?

Natural slate is split shale stone — one of the oldest and most durable roofing materials. Lifespan of 100–150 years or more. The low carbon footprint is because production is primarily mechanical splitting, not thermal treatment. Used on historic buildings and as premium roofing.

Carbon Footprint Compared

Natural slate ← this material 0.058 kg CO₂/kg

Concrete roof tile 0.25 kg CO₂/kg

Roofing felt 1.2 kg CO₂/kg

Roofing membrane 2.5 kg CO₂/kg

Negative carbon footprint (green) indicates carbon storage. Data based on EPD averages from ECO Platform and estimates per EN 15804.

Typical Applications

check_circle Historic and heritage buildings
check_circle Pitched roofs with inclination 30–60°
check_circle Premium residential construction
check_circle Facade cladding

In Renovation

Natural slate is a classic choice for renovating historic buildings and listed properties. It is the roofing material with the lowest carbon footprint and the longest lifespan.

Questions about natural slate

Where does natural slate come from?

Mostly from Spain (Galicia), Wales, and Brazil. Spanish slate is the most widely used in Denmark. Quality varies — look for S1 or T1 classification for the best durability.

Is natural slate expensive?

Yes — natural slate costs 2–3x more than concrete tiles in material cost. But with a lifespan of 100+ years, it is actually cheaper per year of service than most alternatives.

Does slate require maintenance?

Minimal. Slate tiles are robust and rarely need repair. Nails and the wooden battens holding the tiles can rust and rot after 40–60 years and require periodic inspection.

Is natural slate suitable for all roof types?

Natural slate requires adequate pitch (min. 25–30°) and a structure that can bear the weight (approx. 30–50 kg/m²). It is not suitable for flat roofs.

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