A Jack Arch roof is usually formed with number of 4.5 inches thick brick masonry
segmental arch of 6-9 inches rise from centre for 4 - 6 feet span supported by Rolled Steel Joist (RSJ) spanned over shorter dimension of room from wall to wall.
Y Bont Fawr, with its three
segmental arches and cut-waters, has dominated the life of Llanrwst since it was first built in 1636.
At first this was occupied by a vendor of garden furniture; subsequently it was filled by a cast-iron canopy, various wooden shacks and cab shelters, and an entrance to the tube railways below, hiding the original open arcade of
segmental arches. In the 1960s all this was cleared away only to be replaced by a new unsightly extension to the station.
Most of the windows are crowned by projecting brick
segmental arches, and some are trimmed with bluestone.
In the next century even larger,
segmental arches (i.e.
It is a decorative cast iron, three
segmental arched structure with a 22-metre span.
Upon entering the Post Office from Main Street, one passes through a wooden,
segmental arched doorway which opens into a reconstructed glass vestibule.
The prayer hall consists of arches on pillars, with
segmental arches on segmental vaults running parallel to the qibla wall on the east side.