Difference between cofferdams and caissons
Cofferdams and caissons are both structures that are used when undertaking construction works in areas submerged in under water.
The main difference between the two is that a cofferdam is a temporary structure which is removed after completion of the work, whereas a caisson is built to remain in place as part of the completed structure.
The aim of a cofferdam is to be as watertight as possible to create a dry area in which to carry out the required works, or at least to limit water ingress to a safe level that can be pumped away.
A caisson is typically a box-like structure made of materials such as timber, steel, masonry and reinforced concrete. It may be constructed onshore then floated to the required location, where it is sunk into place, enabling access to the bed to undertake works.
The type of structure being built will determine whether a caisson or a cofferdam is most suitable. The two principal factors influencing the choice are the ground conditions and the depth to which the work is to be taken. In general, cofferdams are suitable for depths of up to 18 m below high water level, while caissons are more suitable for greater depths.
[edit] Related articles on Designing Buildings Wiki
Featured articles and news
Shortage of high-quality data threatening the AI boom
And other fundamental issues highlighted by the Open Data Institute.
Data centres top the list of growth opportunities
In robust, yet heterogenous world BACS market.
Increased funding for BSR announced
Within plans for next generation of new towns.
New Towns Taskforce interim policy statement
With initial reactions to the 6 month policy update.
Heritage, industry and slavery
Interpretation must tell the story accurately.
PM announces Building safety and fire move to MHCLG
Following recommendations of the Grenfell Inquiry report.
Conserving the ruins of a great Elizabethan country house.
BSRIA European air conditioning market update 2024
Highs, lows and discrepancy rates in the annual demand.
50 years celebrating the ECA Apprenticeship Awards
As SMEs say the 10 years of the Apprenticeship Levy has failed them.
Nominations sought for CIOB awards
Celebrating construction excellence in Ireland and Northern Ireland.
EPC consultation in context: NCM, SAP, SBEM and HEM
One week to respond to the consultation on reforms to the Energy Performance of Buildings framework.
CIAT Celebrates 60 years of Architectural Technology
Find out more #CIAT60 social media takeover.
The BPF urges Chancellor for additional BSR resources
To remove barriers and bottlenecks which delay projects.
Flexibility over requirements to boost apprentice numbers
English, maths and minimumun duration requirements reduced for a 10,000 gain.
A long term view on European heating markets
BSRIA HVAC 2032 Study.
Humidity resilience strategies for home design
Frequency of extreme humidity events is increasing.
National Apprenticeship Week 2025
Skills for life : 10-16 February