As noted in the Publisher’s Foreword, the following summaries do not pretend to embrace all the practical directives that must be mastered if one is to rest assured that his sukkah is in fact kosher.

Summary of Section 626

(a) S’chach must be put in place for the purpose of shade. If it is put in place for other reasons, e.g., to create a dwelling or a storehouse, it is invalid (subsection 1).

(b) The s’chach must be positioned under the open sky, not under an invalid covering such as a tree or overhanging balcony. If it is placed under an invalid covering, the shade from the invalid covering disqualifies the shade produced by the s’chach directly beneath it (subsection 2).

(c) A sukkah is invalid if its s’chach casts a shadow over less than half of its floor area (subsection 3).

(d) If valid s’chach is mixed with invalid material, there are situations in which it would be considered acceptable. However, there are many factors involved. Hence if a person finds it necessary to construct a sukkah in such a manner, he should consult a competent Rabbinic authority with regard to the particulars.

(e) There is a general principle that applies with regard to s’chach. The Torah states, “Make the Sukkos festival for yourself.” Implied is that the s’chach of a sukkah must be made. We may not use something that was initially invalid for s’chach, but which later became suitable as a matter of course, for the initial act of making, which was invalid, is not considered “making” at all (subsection 16).

(f) It is permitted to make a sukkah in a house below a roof from which the shingles were removed with the intent of making a sukkah, even if the wood or the beams on which the shingles had been resting remain. Indeed, the beams themselves can be considered as part of the s’chach. The reason that this is not considered as a contradiction to the above principle is that one performed an action and removed the shingles with the intent of making a sukkah for shade. Hence it is considered as if he performed an action with regard to the wood or the beams themselves and prepared them for the sake of the sukkah (subsection 17).

(g) If, however, a building was initially constructed with beams that were fixed in place as part of the structure, but they were never covered with roofing material, they are invalid for use as s’chach, and indeed can disqualify valid s’chach (subsection 12).

(h) If s’chach is disqualified by an external factor – e.g., one constructed his sukkah under the roof of a house and, after placing s’chach upon it as required by law, removed the roof of the house that was above the sukkah – itis valid, even though no action was taken with the s’chach itself to make it valid (subsection 17).

(i) When one is making a sukkah under a hinged roof that can be opened and closed at will, he must be careful to put the s’chach in place while the roof is open. Since it is already on hinges, opening it is not considered as an act of sufficient importance to validate s’chach placed upon it previously (subsection 19).

(j) Such a retractable roof fits the halachic definition of an entrance and may be closed and opened on Shabbos and the festivals. Doing so does not involve the forbidden labors of destroying or building (subsection 20).

(k) When the retractable roof is closed, one must be careful not to sit under it with the intent of fulfilling the mitzvah of the sukkah, for at that time the sukkah is not valid and one does not fulfill his obligation by dwelling in it (subsection 21).

Summary of Section 627

(a) One is required to dwell directly under the s’chach, with no other shelter (ohel) intervening.The term ohel is used only for a structure that is at least ten hand­breadths above the ground. Even if it has no walls, it is placed in that category and it is forbidden to dwell under it (subsection 1).

(b) Any roof that is a handbreadth wide and ten handbreadths above the ground is defined as an ohel (subsection 2).

(c) Stringency is sometimes required even when a canopy within a sukkah does not have a roof that is a handbreadth wide; for example, a canopy that hangs down from its horizontal beam, and within three handbreadths of that beam it spreads out on either side, creating a horizontal span of a handbreadth. The rationale is that any space of less than three handbreadths is governed by the principle of lavud, so that the entire space is considered as if on the same level (subsection 3).

(d) Decorative objects may be hung in a sukkah, whether on the walls or under the s’chach, even though they are invalid as s’chach. Even a four-handbreadth piece of such fabric does not disqualify the sukkah. It is even permitted to sit directly below such decorative hangings, because they are subordinate to the s’chach, provided they are within four handbreadths of it.If they are lower than four handbreadths from the s’chach, they are not considered as subordinate to it and they disqualify the sukkah, as is the case with other materials that are invalid as s’chach (subsection 4).

The above leniencies do not apply if an object is hung under the s’chach for purposes other than decorating the sukkah (subsection 6).

(e) Material that is invalid as s’chach does not disqualify a sukkah unless it measures four handbreadths or more (subsection 4).

Summary of Section 628

(a) When one valid and sturdy sukkah is constructed on top of another, the lower sukkah is invalid by Scriptural decree. If the upper sukkah is either structurally or halachicallyunacceptable, the lower sukkah may be used if it is valid (subsection 1).

(b) Invalid material disqualifies the valid s’chach below it only when the invalid material is inherently unsatisfactory; e.g., it is still connected to the ground or it is susceptible to contracting ritual impurity. When, however, the s’chach is inherently valid but is invalidated by an external factor – for example, by being situated more than 20 cubits above ground level – it does not disqualify the valid s’chach below it, for it is inherently suitable for use as s’chach for the lower sukkah (subsection 2).

(c) A sukkah that cannot withstand ordinary land winds is invalid. This applies even when there is no wind at all. If the sukkah can withstand the winds common on land, it is valid even if it cannot withstand the winds common at sea (subsection 4).

(d) A sukkah on a camel or on top of a tree is valid. One may not, however, climb up to it on Shabbos or on a festival, when it is forbidden to make use of any living creature or of any plant connected to the ground. We do not override even a shvus – whichwas ordained by the Sages – in order to enable the observance of the mitzvah of sukkah (subsection 5).

(e) For several reasons, it is undesirable that the base of the sukkah be positioned on the ground, with its s’chach resting on a nearby tree (subsection 6-7).

(f) The supports for the s’chach of a sukkah must be stationary, unless the entire sukkah is built on a movable base, such as on a camel, a ship, or a wagon (subsection 4, 8).

(g) It is forbidden to make use of the appendages of a tree on Shabbos or on a festival (subsection 6). Hence one may not climb up to a sukkah using a ladder supported by a tree even if there is no problem in using the tree itself (subsection 9).

Summary of Section 629

(a) To be valid for use as s’chach, a substance must:

(i) have grown from the ground;

(ii) be presently detached from the ground; and

(iii) not be susceptible to ritual impurity.

This excludes all kinds of foods, utensils, animal substances and metals (subsection 1).

(b) Anything that was susceptible to ritual impurity even briefly may not be used for s’chach, even though later its status changed and it was no longer susceptible to ritual impurity. This category includes:

(i) broken utensils, when the pieces are not large enough to be susceptible to ritual impurity;

(ii) pieces of cloth that are so tattered that less than three fingerbreadths by three fingerbreadths remains;

(iii) the detached handle of a utensil (subsection 2).

(c) Any article that serves as a receptacle is considered a utensil and hence is unfit for use as s’chach (subsection 3-4).

(d) Natural fibers that have been processed to be used as fabric are invalid for use as s’chach (subsection 5).

(e) Mats that were made to sit on or to lie on are invalid for use as s’chach. Those made for shade are acceptable (subsection 7).

(f) An object that is susceptible to ritual impurity, such as a chair or a bench, should preferably not be used to hold the s’chach in place or to support it (subsection 11). After the fact, if one already supported the s’chach itself with something that is susceptible to ritual impurity, one may sit under it and discharge one’s obligation thereby (subsection 13).

(g) The s’chach may be placed on beams or pegs which are placed on an object that is susceptible to ritual impurity. It is of no consequence that the object that supports the s’chach or holds it in place is supported by something that is invalid as s’chach (subsection 12).

(h) All accessories to food – such as the straw of ears of grain, the twigs to which grapes are attached, and the branches to which dates are attached – are susceptible to ritual impurity. However, this applies only up to a certain length (subsection 15).

(i) As mentioned at the outset, fruit and vegetables are not valid for use as s’chach. Moreover, they and their accessories can disqualify valid s’chach. Nevertheless, if branches with fruit were cut down for the express purpose of being used as s’chach, the accessories are not disqualified as s’chach (subsection 16).

(j) Leaves that will dry, wither, and fall from a branch within seven days are considered from the outset as if they have already fallen, even though they have not yet dried. Hence, three handbreadths of such a covering, even if they are at the side of a sukkah, disqualifies the sukkah as empty space would (subsection 19).

(k) Anything that is still growing in the ground may not be used as s’chach because it does not resemble “the remnants of the threshing floor and the winepress,” which have been detached from the ground (subsection 20).

(l) Moreover, if one covered a sukkah with branches that were connected to the ground and then detached them, the s’chach is invalid. This is derived from the verse, “Make the Sukkos festival....” Implied is that one must make the sukkah, and not use something which was already made in an unacceptable manner. One may rectify this disqualifying factor by picking up the s’chach and putting it down again after it was detached from the ground (subsection 20).

(m) The Sages forbade using the following materials as s’chach as an initial preference:

(i) grasses with an unpleasant smell, which are invalid even though they are not edible and are not susceptible to ritual impurity;

(ii) certain kinds of brambles whose leaves fall even when there is no wind.

The rationale is that they may cause people to leave the sukkah. Nevertheless, if one transgressed and used them as s’chach, the sukkah is valid (subsection 21).

(n) The Sages decreed that bundles of straw or bundles of wood may not be used for s’chach while they are bound together (subsection 22). If one transgressed and used a bundle as s’chach, he may untie it and thus render the s’chach valid, provided the bundle was placed there for the purpose of shade. This leniency is granted because bundles are deemed invalid only by Rabbinic ordinance, as explained above (subsection 28).

(o) The Talmudic Sages decreed that boards that are four handbreadths wide or more may not be used as s’chach, because the ceilings of most homes were once made of such boards (subsection 29). Even if the boards are laid on their sides and the sides are less than four handbreadths wide, the boards should not be used as s’chach (subsection 30).

(p) More recently, however, homes are sometimes roofed by boards that are less than three handbreadths wide. The medieval halachic authorities known as Rishonim therefore extended the above prohibition and ruled that a sukkah should be disqualified even if boards less than three handbreadths wide are used as s’chach (subsection 32).

(q) In a pressing situation, where there are no alternative materials for s’chach, one may use boards even if they are more than four handbreadths wide (subsection 33).

Summary of Section 631

(a) The shaded area of a sukkah floor must exceed the area exposed to sunlight (subsecs. 1-3). If a sukkah isconstructed in this manner, one may even dwell in the part of a sukkah in which the sunlight exceeds the shade, for this area is batel – insignificant and therefore nullified – vis-à-vis the majority of s’chach, under which the shade exceeds the sunlit area.

Nevertheless, if the minority of s’chach, under which the sunlit area exceeds the shade, is as large as seven handbreadths by seven handbreadths, it is considered significant and one cannot fulfill one’s obligation by dwelling under it (subsection 4).

(b) When s’chach is so thick that it prevents rain from entering, it is invalid, because the shelter then resembles a house (subsection 5).

(c) If the s’chach was disordered, i.e., parts of it were on a higher level than others, the sukkah is valid, because the two levels of s’chach together are considered as a single covering of s’chach. If, however, the two levels are separated by three handbreadths or more, they do not combine and are not considered as a covering of s’chach at all (subsecs. 6-7).

(d) Moreover, if the width of the higher level of s’chach meets at least the minimum requirement to be called a roof, a handbreadth by a handbreadth, and it is positioned exactly over a corresponding open space on the lower level, the sukkah is valid, even though there are more than three handbreadths between the two. We consider the s’chach on the higher level as if it had descended downward and was positioned in the empty space under it.

The above applies provided the area of the empty space is at least the same as the area of the upper level of s’chach. If it was less than it, or if the higher level of s’chach was not positioned exactly over the empty space below it, but instead, were it to be lowered, part of it would touch the lower level of s’chach, the higher level is not considered as if it had come down to the lower level (subsection 7).

(e) When canes of s’chach project outward behind the sukkah and two of the walls extend together with them, it is considered as if a new and valid sukkah was constructed, provided the following conditions are met:

(i) these canes extend over the minimum area of a sukkah, which is seven handbreadths square;

(ii) the shaded area on the floor under them exceeds the sunlit area; and

(iii) there are now three walls – the middle wall and the two long walls that extend together with the canes.

This is true even though the middle wall was not constructed with this intent, but to serve the main sukkah (subsection 8).

(f) A similar law applies if a sukkah does not have a wall on its fourth side and the canes project outward on this open side. If the canes covering this addition extend over the minimum dimensions of a sukkah, this additional area is also considered as part of the sukkah and one may sit there even though it has only one wall (subsection 9).

(g) Four handbreadths of invalid covering in one place in a large sukkah, or three handbreadths of such covering in a small sukkah (i.e., one that is only seven handbreadths square), is considered as a separate area and can disqualify the entire sukkah in certain situations (subsection 10).

(h) When a sukkah is covered partly with valid s’chach and partly with materials that are invalid as s’chach, it is acceptable even if the valid s’chach is somewhat sparse, provided the length and the width of the area covered by valid s’chach are equivalent to the length and width of the area covered by invalid s’chach. One must, however, place a little additional valid s’chach to overlap the invalid s’chach (subsection 11).

(i) When a structure is roofed with boards, the boards are unacceptable for use as s’chach regardless of their size, because they were put in place to create a dwelling, not for shade alone. To make such a structure acceptable as a sukkah, every alternate board must be removed and valid s’chach must be put in its place (subsection 12).

Summary of Section 637

(a) A person who did not build a sukkah before the festival, whether unintention­ally or intentionally, should build one during Chol HaMoed (subsection 1).

(b) It is permitted to leave one sukkah and dwell in another. There is no require­ment to dwell in the same sukkah for all seven days (subsection 2).

(c) The Torah states, “Make the Sukkos festival for yourself,” implying that the sukkah must be “your own” and not your friend’s. One may, however, fulfill his obligation with a borrowed sukkah. Since he enters it with permission, it is considered as his (subsection 3).

(d) Although a sukkah must be one’s own, a stolen sukkah is acceptable after the event in certain circumstances (subsections 4-9). Initially, however, one should not use a sukkah constructed on another’s property. If one did, no blessing should be recited when such a sukkah is used (subsection 11).

(e) One should initially not build his sukkah on another’s land without his consent, for the owner could possibly object to having a dwelling erected on his property in such a way (subsection 10).

(f) Similarly, a sukkah should preferably not be constructed on land belonging to people at large, such as a public place or thoroughfare (subsection 11).

Summary of Section 638

(a) It is forbidden to derive benefit from the s’chach of a sukkah. Since it is used for a mitzvah, holiness rests upon it. This prohibition applies throughout the entire festival and applies even if the sukkah collapses (subsection 1).

(b) According to Rabbinic decree, this prohibition also applies to the walls of the sukkah (subsection 2). Thus it is forbidden to take a sliver of wood from the walls or s’chach for use as a toothpick or the like. It is, however, permitted to use and derive benefit from the walls in a manner that does not deprive them of the holiness of the sukkah. Thus one may place or hang objects on them, or smell them if they are made of fragrant wood (subsection 5).

(c) Similarly, it is forbidden to make use of the decorations of the sukkah throughout the festival. This prohibition leads to a further restriction: It is forbidden to move them on Shabbos or Yom-Tov, even to protect them from rain or thieves (subsection 6).

(d) One may, however, avert the latter restriction by stating in advance that he intends to make use of the decorations in the course of the festival. For that stipulation to be effective, he must say, “I will not refrain from making use of them throughout the time of bein hashmashos on all the eight days of the festival.” Thus, at the time the holiness of the sukkah would rest upon them – bein hashmashos, the twilight time with which the Yom-Tov begins – this holiness will not rest upon them at all and they are never considered as having been set aside for the mitzvah (subsection 7). If one does not use this exact wording, it is possible that the holiness of the mitzvah will rest on the decorations, despite his stipulation (subsection 8).

(e) According to one authority, when valuable objects are used as decorations for a sukkah, it is considered as if an appropriate stipulation has been made concerning them, for this is one’s presumed intent. Nevertheless, an explicit stipulation should be made (subsection 11).

(f) The leniency effected by such a stipulation applies only to the decorations, but not to the s’chach or the walls (subsection 12).

(g) All of the above restrictions apply only after one has actually made use of the sukkah for the mitzvah. If one has not done so, even if he intended to do so and designated the walls and the s’chach for this purpose, they may still be used for mundane purposes (subsection 15).

(h) After the festival the s’chach may be used for mundane purposes, though not in a manner that would be disrespectful to the mitzvah (subsection 17).