Ciria C660 Excel Spreadsheet Extra Quality Now

C660 has not been superseded as of 2025, but CIRIA is working on a replacement (C801 – ground gas guidance update). When that arrives, your spreadsheet logic will need a major overhaul.

A purpose-built CIRIA C660 Excel spreadsheet automates repetitive calculations and enforces the logic of the guidance. Here’s why the industry has embraced it:

| Pitfall | Spreadsheet solution | |---------|----------------------| | Using raw gas % instead of GSV | The spreadsheet forces GSV calculation before hazard classification. | | Ignoring CO₂ as a hazard despite high methane | The matrix combines both gases; high CO₂ can trigger Category 5 even if methane is moderate. | | Selecting the wrong Characteristic Situation (e.g., CS2 instead of CS3) | Dropdown menus and look‑ups prevent manual misclassification. | | Forgetting to correct flow rates to standard temperature (20°C) and pressure (1013 mbar) | Built‑in correction factors applied automatically to GSV. | | Mixing up units (e.g., l/hr vs. ml/min) | All cells use consistent units; conversion is internal. | | No audit trail for regulators | The spreadsheet can be printed with formulas shown or saved as a locked archive. | ciria c660 excel spreadsheet

| Adoption Status | Date | Correspondence | | --- | --- | --- | | Submitted | 2023-03-01 | Email to local authority | | Approved | 2023-03-15 | Adoption letter received |

Let's walk through a real-world scenario: A proposed housing development on a former landfill site. C660 has not been superseded as of 2025,

“We require all gas risk assessments to be undertaken in accordance with CIRIA C660. Where spreadsheets are used, they must clearly show the calculation of GSVs and the assignment of Characteristic Situations.” – Typical EA comment on planning condition discharge.

has been the industry benchmark for predicting early-age temperature rise and managing thermal cracking risks. However, as design codes evolve, so do our tools. Key Features of the C660 Spreadsheet: Temperature Modeling: Here’s why the industry has embraced it: |

CIRIA C660 Excel Spreadsheet is a widely used technical tool for estimating early-age thermal crack development in concrete structures. While originally published in 2007, it has largely been superseded by the more refined CIRIA C766

The Excel spreadsheet is a technical tool used by structural engineers to predict and control early-age thermal cracking in concrete. It automates complex calculations derived from the CIRIA C660 (and its successor C766) guidance to ensure structural integrity in mass concrete pours. 🛠️ Key Capabilities