818. Braiding, Assembling

Shabbos 22:26

One may not braid or part hair, as these activities resemble building. A candlestick of separate pieces may not be assembled on Shabbos, nor may a chair or a table of pieces be assembled, as this resembles building. If one does assemble one of these things, he would not be liable because the primary labor of building, and its reciprocal labor of demolishing, do not apply to utensils. If the parts of one of these utensils are already put together loosely, one may finish assembling it. One may not adjust the vertebrae of a child’s spine on Shabbos as this resembles building.

Shabbos 22:27

One who erects a permanent tent is liable for performing a subordinate labor of building. Therefore, one should neither erect nor demolish even a temporary tent out of concern that one may come to erect or demolish a permanent tent. If one does erect or demolish a temporary tent, he would not be liable. One is permitted to add on to a temporary tent on Shabbos. Let’s say, for example, that a cloth was spread over pillars or walls and it was rolled up before Shabbos. In such a case, if a portion the size of a handbreadth (about 3”) hung down before Shabbos, one may extend it until reaches its full size on Shabbos, forming a large tent. The same is true in all similar scenarios.