# How do I calculate the carbon footprint of a fibre cement roof sheet?

Canonical: https://senseible.earth/answers/fibre-cement-roof-sheet-carbon-footprint-per-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.

- [Product carbon footprint calculator](https://senseible.earth/calculators/product-carbon-footprint)
- [Fly ash brick footprint](https://senseible.earth/answers/fly-ash-brick-carbon-footprint-per-1000)
- [Paver block footprint](https://senseible.earth/answers/paver-block-carbon-footprint-per-square-metre)
- [Cement industry](https://senseible.earth/industries/cement)

Sources: [GHG Protocol Product Standard](https://ghgprotocol.org/standards), [ISO 14067:2018, Carbon footprint of products (iso.org)](https://www.iso.org), [IPCC 2006 Guidelines, Volume 2 Energy (fuel defaults)](https://www.ipcc-nggip.iges.or.jp/public/2006gl/vol2.html), [CEA CO2 Baseline Database, version 21.0](https://cea.nic.in/cdm-co2-baseline-database/?lang=en)

Last reviewed 2026-10-20.