The crown-post roof appeared in England in the second half of the thirteenth century and persisted until the early sixteenth century in the south-east of England. Rafter holes are found in these roofs near to the feet of the rafters on their lower faces. They are blind holes typically 75 mm to 100 mm deep by about 25 mm in diameter. Various theories have been put forward over the years to explain their function. This paper reviews the evidence found on the rafters and integrates it into a revision of one of the earlier theories which suggested that rafter holes formed part of a jig or templet. This jig was used to ensure that the collars were at the correct height relative to the crown plate (or collar purlin). These ideas have been applied in the prefabrication of a new crown-post roof. Evidence is also presented showing how the practice of using jigs to help prefabricate rafter cross-frames may also have been applied to some other roof types such as scissor-braced and side-purlin roofs, in south-east England.

冠柱式屋顶于十三世纪下半叶出现在英格兰，并在英格兰东南部一直持续到十六世纪初。在靠近椽子底面的这些屋顶上发现了椽子孔。它们是通常 75 毫米至 100 毫米深、直径约 25 毫米的盲孔。多年来已经提出了各种理论来解释它们的功能。本文回顾了在椽子上发现的证据，并将其整合到对早期理论之一的修订中，该理论认为椽子孔是夹具或模板的一部分。该夹具用于确保项圈相对于冠板（或项圈檩条）处于正确的高度。这些想法已应用于新冠柱屋顶的预制。