Tunnel form

Tunnel form is a formwork system that allows the contractor to cast walls and slabs in one operation in a daily cycle. It combines the speed, quality and accuracy of factory/off-site production with the flexibility and economy of in-situ construction and is recognised as a modern method of construction (MMC).

The result is a cellular reinforced structure, the surfaces of which are sufficiently high quality to require only minimal finishing for direct decoration, while the end walls and facades are easily completed with thermally insulated units that can be clad as required.

The system creates an efficient load-bearing structure for use in a wide variety of applications. It is particularly effective in projects suited to repetitive cellular construction such as residential blocks, hotels, student accommodation, barracks and prisons.



The formwork is specially adapted for each project. The repetitive nature of the system and the use of prefabricated forms and reinforcing mats/cages simplifies the whole construction process, producing a smooth and fast operation. The techniques used are already familiar to the industry, but with tunnel form construction there is less reliance on skilled labour.


Quality is enhanced despite the speed of construction. The precise, even steel face of the formwork creates a smooth, high quality finish capable of receiving direct decoration with the minimum of preparation (a skim coat may be required). This reduces the requirement for following trades, thus providing additional cost savings and speeding the entire process.


The large bays constructed using tunnel form provide exceptional flexibility in the design and layout of the building and allow a high degree of freedom in the final appearance.


Tunnel form has integral working platforms and edge protection systems. In addition, the repetitive, predictable nature of the tasks involved encourages familiarity with operations, and, once training is complete, productivity improves as construction progresses. The minimal requirement for tools and equipment when moving the tunnel form further reduces the risk of accidents on site.


The insitu casting of units on site and the local availability of ready-mixed concrete supplies reduce transportation impacts.

Just-in-time deliveries and near zero wastage produce an overall tidier site with associated cost savings and safety benefits.

Concrete’s thermal mass coupled with correct insulation and boiler design minimises heating costs and can even reduce air-conditioning requirements