The Material Culture of the Cook Islands (Aitutaki)
The Roof Ridging
The Roof Ridging.
To prevent leakage between the uppermost rows of thatch, a form of ridging had to be devised. This consisted of a nikau sheet plaited in a particular way and termed a page 25tapatu. They are sometimes referred to as tapoki, but like the Maori taupoki, it is a general term for a cover or lid. In Raratonga and Mangaia, the special ridging mat is named au.
Plaiting the Tapatu. A tapatu length is plaited from two leaves, one of which is split down the midrib. The whole leaf occupies the middle position whilst a half leaf is placed on either side in such a way that the midrib strips are to the outside and the leaflets cross those of the middle leaf as shown in Fig. 28.
Thus the leaflets on the left side of the middle sheet A, diagonally cross those of the half leaf B. on its left, and those on the right cross in a similar manner. We have the crossing elements for a plait naturally provided. The midribs of B. and C. are placed about 10 inches from the midrib of A.
As the sheet is usually turned over when fixing on the roof, theoretically the sheets should be plaited with the under surface (tua) upwards, but no attention was paid to this in the demonstration given to the author. The shiny surface was kept upwards. The leaflets were not opened out but were kept doubled, with the midrib forming the forward edge of the leaflet elements in the plait. The plait was a single check, but sometimes a twilled two is used.
The procedure is merely the continuation of this check technique, care being taken to maintain the midribs an even distance apart. Where necessary, two leaflets may be run together as a single plaiting element. When a suitable distance has been plaited on the left side, attention is turned to the right.
The right half sheet, which has really not been placed in position at the very start, is now laid parallel. It will be seen that the leaflets from B. overlap beyond the midrib of C. The free ends of B. are simply kept turned back to the left by the left hand, whilst A. and C. are plaited together as in the case on the left and for a similar working distance. For clearness, the end of the leaflets from C. are not shown in Fig. 29.
Another section is done on the left and then the right catches up. With many, this technique is considered sufficient and the sheet is finished off with the ends of the leaflets from B. and C. merely crossing each other in the middle line.
Preparatory Steps. Before the tapatu ridge sheets are put on, layers of grass known as mata are laid over the ridging. This is to round off the part near the taorangi horizontal pole which rests on the forks made by crossing the kaho above the ridge-pole or tahuhu. In Raratonga a hardy mountain fern called moa is also used.