Daf Yomi - Sukkah 8 - Who Places the S'chach?

The reason that a goy, woman or animal can make a sukkah is because a sukkah does not have to be built with the intention for the mitzva, it is valid as long as the intention was to be used for shade.

The Bikurei Yaakov rules that this is only bdieved, however it is preferable that the s'chach should not be placed on the sukkah by a goy, woman or minor.

He bases this on a Magen Avrohom 649:8 that rules that it's preferable that a goy should not be the one to tie the lulav together, even though a lulav is not necessary to be tied, but since it is glorifying the mitzva, it should not be done by someone who is not obligated in the mitzva.

Sheorim Mitzuyanim Bhalacha differs and states that there is a distinction between lulav and s'chach. Preparing the lulav which is glorifying the mitzva is a segment of the mitzva and therefore should not be performed by a goy, however the placing of the s'chach that doesn't even have to be done for the sake of the mitzva, rather just for providing shade, perhaps it can be done by a goy even l'chatchila.

The Ksav Sofer O"C 9 discusses the permissibility of a minor placing the s'chach on the sukkah. Firstly, he states, it is not an obligation to place the s'chach with an intention of providing shade, which would prevent a minor from performing this for perhaps he won't have this intention, rather it is integral that the s'chach is not placed there for other motives like storage or dwelling and therefore a minor can do it. Secondly, it is possible that the intention of the baal habayis that the s'chach should provide shade is sufficient.

There might possibly be an inyon for the baal habayis to place the s'chach himself due to the principle of mitzva bo yoser mibeshlucho.