How do I calculate the carbon footprint of a fibre cement roof sheet?
Cement is the main input: multiply the cement per sheet by the cement maker's per-kg figure. Add fibre, fly ash and the plant's forming, steam curing and electricity, then divide by sheets made and report by length and thickness.
Materials
- Cement by weight per sheet.
- Cellulose or synthetic fibre.
- Fly ash and water.
Process
- Slurry mixing and sheet forming.
- Corrugating and stacking.
- Curing with steam or air, and trimming.
Per sheet
Report per sheet with length and thickness, and per square metre for comparison with metal roofing.
Worked example: fibre cement roof sheet unit per sheet (one month)
- Electricity: 50,000 kWh x 0.710 = 35,500 kg CO2
- Coal: 40,000 kg x 2.42 = 96,800 kg CO2
- Sheets made: 60,000
- Plant total: 132,300 / 60,000 = 2.205 kg CO2 per sheet
- Add cement and fibre for the full figure
Inputs are illustrative; use your own bills and production records.
What Senseible does here
Senseible reads the plant's electricity bills (CEA grid factor 0.710 kg CO2 per kWh, CO2 Baseline Database version 21.0) and fuel invoices (IPCC 2006 defaults) into a fingerprinted Scope 1 and 2 record, the plant-level input to a per-unit figure. Bought-in materials go to the supplier evidence trail; product reports are self-declared drafts.
Sources: GHG Protocol Product Standard, ISO 14067:2018, Carbon footprint of products (iso.org), IPCC 2006 Guidelines, Volume 2 Energy (fuel defaults), CEA CO2 Baseline Database, version 21.0
Last reviewed 2026-10-20.