Barrel Vaults ~ these are single curvature shells which are
essentially a cut cylinder which must be restrained at both ends to
overcome the tendency to flatten. A barrel vault acts as a beam
whose span is equal to the length of the roof. Long span barrel
vaults are those whose span is longer than its width or chord
length and conversely short barrel vaults are those whose span is
shorter than its width or chord length. In every long span barrel
vaults thermal expansion joints will be required at 30„000 centres
which will create a series of abutting barrel vault roofs weather
sealed together (see next page).Typical Single Barrel Vault Principles~Shell Roof Construction