Freeboard
Culvert, screen and outfall manual, (CIRIA C786) published by CIRIA in 2019, defines freeboard as: ‘An allowance for uncertainty in design water level and any other physical processes that may affect the ability of an asset to withstand the design water level such as wave action or superelevation.’
See also Residual uncertainty allowance.
Containment systems for the prevention of pollution, Secondary, tertiary and other measures for industrial and commercial premises (CIRIA C736), published by CIRIA in 2014 defines freeboard as: ‘An allowance in the form of increased height of a containment wall for additional capacity over and above the minimum design requirement.’
Rules of Thumb, Guidelines for building services (5th Edition) BG 9/2011, by Glenn Hawkins, published by BSRIA in 2011, defines freeboard as: ‘The vertical distance in a water tank between the maximum water level and the top of the tank’. This definition is repeated in BG 87/2024, Useful Information Guide, written by Chin Hang “Kay” Lam and published by BSRIA in 2024.
High Speed Rail (Crewe – Manchester) Environmental Statement, Glossary, abbreviations and references, published by the Department for Transport in 2022, defines freeboard allowance as:
The height from the maximum design level of a watercourse to:
- the adjacent banks of an open channel, to provide a factor of safety against flooding; or
- the soffit (underside) of any culvert or bridge above, to reduce the risk of blockage by floating debris, etc.’
[edit] Related articles on Designing Buildings
Featured articles
Check out some of the best features and news from Designing Buildings as well as key stories from around the web.
Minimum energy efficiency standards (MEES)
CIAT briefing on response to consultations for privately rented non-domestic properties.
Connect, collaborate, shape the future
Registration now live for UK Construction Week Birmingham.
CIOB announces Saul Humphrey FCIOB as new President for 26/27 term.
A quick, simple, and zero-bills solution to prevent overheating.
The adaptive reuse of large industrial structures.
Promoting the circular economy by extending the life of buildings.
CIAT responds to Climate Change Committee report
An urgent wake-up call for both government and the built environment.
Construction Management, 24 June
FMB pilot aims to build pipeline of site-ready tradespeople.
A quick introduction.
CLC publishes Mental Health Joint Code of Practice.
A quick introduction to its uses and risks.
Construction Management, 17 June
Government rolls out digital planning tool to all local authorities.
Your views needed - a strategy for the professions, trades and occupations.