Building takes place in stages, with the formwork being repositioned as often as necessary. This is one of the most interesting methods, but applies only to barrel vaults.
Corbel vaults can be built only using small spans. Building in so-called "slices", without formwork, is the most economical method. This exploits the properties of certain mortars which enable the bricks to be laid face on layers leaning at a steep angle to the vertical. To improve adhesion, small and fairly thin elements of regular dimensions should be used. Using this principle, and by varying the shape and the size of the courses, one can build barrel, groined, dominical, trough, squinch and boat vaults. Traditionally, all these vaults are built "by eye", but light tools can be used to guide the masons so that they build the required shape correctly.
Building techniques without formwork are always preferred as a formwork would be too complicated to manufacture.
This enables large areas to be covered, but results in conical forms which are very high relative to the span.
Increasingly inclined rings:
Horizontal rings which gradually decrease in diameter can be used to create all types of cupolas. This method uses the same brick-laying technique as for vaults built in "slices". Simple rotating guides which describe the form in the air can be used to obtain correct, regular forms.
Using a straw-reinforced earth mortar, it is possible to build fairly large sized cupolas. These are built up in successive layers.
Building a barrel vault in slices
Building a cupola using inclined ring-courses