Munagi

What munagi means

The munagi, or ridge beam, is the horizontal timber that runs along the top of a roof frame in the direction of the ridge and carries the upper ends of the rafters from both slopes. It is the highest member of the roof structure and fixes the apex of the roof. Setting it in place, jōtō or muneage, marks a milestone in construction and has long been accompanied by a ceremony.

How the ridge beam is supported depends on the roof frame. In the ordinary Wagoya frame, short posts standing on level beams carry it. Gates show how the method varies by type. The front gate of the former Nagashima family house is a Yakuimon in which posts set on a beam spanning the main and rear posts carry the ridge beam, while the garden gate of the same property is an Udekimon in which the main posts carry it directly. Records of this kind show where the ridge beam is supported.

The ridge beam can also date a building. At the ridge-raising, the date, the patron and the carpenters were sometimes written in ink directly on the beam, an inscription called munagi-mei. The record for the Konjikido of Chusonji states that such an inscription shows it was completed in 1124. When the same kind of information is written on a separate board and nailed to the ridge beam, the board is a Munafuda.

Reading the records and the building

The ridge beam appears in records in two ways: in structural descriptions, as when posts on a beam or the main posts carry it, and as the basis for a date. As evidence it appears as an inscription on the ridge beam or, in farmhouses, on the jimune, and the record for a rice storehouse of the Hatakoshi family says its date is known from such an inscription. The jimune is a heavy beam in the farmhouse roof frame running below the ridge, a different position from the ridge beam at the apex.

On site, look for the member running along the apex in buildings with an open or exposed roof. In gates and pavilions where the frame is visible, looking up at the gable end shows the section of the ridge beam and the posts or members that carry it. Records distinguish dates taken from a ridge-beam inscription from those taken from a ridge board, and articles should keep the two apart.