irakagawara 甍瓦

Also called irakamune 甍棟; hon irakagawara 本甍瓦. The roof tiles that form the lowest part of the stack of high ridge tiles that extend far above the structural ridge beam. 

Irakagawara are subdivided into broad concave tiles with a pendant attached, called iraka karakusagawara 甍唐草瓦 or iraka hiragawara 甍平瓦, and semi-cylindrical convex tiles with a pendant attached, called iraka tomoegawara 甍巴瓦 or iraka marugawara 甍丸瓦. The inclusion of the word karakusa, meaning arabesque, or tomoe, meaning comma motif, does not necessarily mean that the pendants are decorated with these motifs. See *karakusamon 唐草文; *tomoemon 巴文. 

It is believed that before the late 16th century, only flat tiles *noshigawara 熨斗瓦, were piled up on the low ridge to make an imposing impression. However, the absence of any transition between tiles stacked up on the ridge and the sloping surface of the roof gave an abrupt, stark appearance. One way to remedy this abrupt change in planes was to arrange a line of irakagawara on either side of the high ridge, achieving an aesthetic contour. At first, ordinary-size broad, concave eave-end tiles *nokihiragawara 軒平瓦, and semi-circular eave-end tiles *nokimarugawara 軒丸瓦, were used, but they proved to be too long. Thus, the irakagawara were shortened. The use of these tiles provided the impetus for further elaboration in ridge design which reached its zenith in the Edo period.