The minimum dimensions of the Sechach [i.e. width and length]-A Teepee shaped Sukkah, portable Sukkah, and car sunroof Sukkah:[1]

Earlier, in Chapter 1 Halacha 6B, we spoke of the minimum dimension of 7×7 Tefachim that is required for the inside of a Sukkah to contain for it to be valid. In this Halacha we will discuss the minimum dimensions of the roof of the Sukkah and its Kosher Sechach and if it too must maintain the minimum dimension of 7×7 Tefachim, or if it is valid even if it is less than 7×7 Tefachim, so long as the inside of the Sukkah contains a 7×7 Tefachim space. It is possible for there to be less than 7×7 Tefachim of Sechach despite the Sukkah containing a 7×7 Tefachim dimension in any of the following scenarios:

1. The Sukkah is made in the form of a Tepee. Portable camp shower structures usually fit this description and hence the question is asked if placing Sechach on their top validates them despite their top not having a 7×7 Tefach dimension. [See Figure A-C]
2. The top of the Sukkah contains invalid Sechach, leaving a less than 7×7 dimension of valid Sechach on top of it. Portable camp shower structures usually fit this description and hence the question is asked if placing Sechach on their top validates them despite their top not having a 7×7 Tefach dimension of Kosher Sehchach. [See Figure D]
3. The top of the Sukkah contains empty space without Sechach, leaving a less than 7×7 dimension of valid Sechach on top of it.

*Important note: The discussion in this Halacha is with regards to the minimum required dimension of the roof and its Kosher Sechach even in a case that this Sechach will provide majority shade to the Sukkah. If, however, the Sukkah does not provide majority shade [such as it contains more empty space than Kosher Sechach on its roof] then it is invalid regardless of its dimension, unless the area of Sechach with majority shade is a 7×7 dimension and contains three Kosher walls, as explained in Halacha 2

A. The law by a tepee shaped Sukkah with less than a 7×7 Tefach dimension on its top:[2]

The Sukkah must maintain a minimum dimension of 7×7 Tefachim throughout its height of ten Tefachim from the ground. [However, past the height of ten Tefachim from the ground it is not necessary for it to maintain a 7×7 Tefachim dimension. Thus, technically, there is no requirement for there to be a 7×7 dimensions of Kosher Sechach on top of the Sukkah, so long as there is a 7×7 dimension of space inside the Sukkah for a height of ten Tefachim.] Accordingly, a tepee shaped Sukkah is Kosher even though its roof does not contain a space of 7×7 Tefachim, so long as there is a space of 7×7 Tefachim within a ten Tefachim height of the Sukkah when measuring from the ground.[3] Nonetheless, even by a teepee shaped Sukkah, there must be a minimum of a Tefach square of Sechach on its roof [Figure A], or it must be lifted a Tefach from the ground [Figure B].[4] If, however, it’s slanted walls are not lifted a Tefach from the ground and it does not contain a Tefach of roof on top, then it is invalid. [Figure C] In addition, in all cases, its walls must be made of material which is Kosher for Sechach being that the walls serve as part of the Kosher Sechach.[5] [From this ruling it can be implied that while there is no requirement to have a 7×7 Tefach dimension on the top area of the Sukkah where the Sechach rests, nonetheless there is a requirement for there to be a total area of 7×7 Tefachim of Kosher Sechach when including also the Sechach material made walls of the tepee Sukkah. However, to have a roofing of less than 7×7 Tefachim of Kosher Sechach and have straight walls, or tepee walls not made of Kosher Sechach, then it would be invalid. In B, however, it is made clear that this is not fully accurate, and in truth there is no requirement to have 7×7 Tefachim of Kosher Sechach, under certain conditions.]

Tepee shaped Sechach [Figure B]:[6] From the above law it is understood that it is permitted to make a slanted Sechach roofing for one’s Sukkah, and it does not have to lie flat, so long as it contains 7×7 Tefachim of Kosher Sechach.

B. The law by a Sukkah that contains a 7×7 Tefachim roof but contains less than 7×7 Tefachim of Kosher Sechach [containing empty space or non-Kosher Sechach to make up the remainder of the roof of the Sukkah]:[7]

[In the previous Halacha in A, we discussed a scenario of a tepee sukkah where it is not necessary for a Sukkah to contain a 7×7 Tefachim dimension of a roof, for it to remain valid. Nonetheless, it was implied from there that there nevertheless remains a requirement for there to be a total area of 7×7 Tefachim of Kosher Sechach when including also the Sechach material made walls of the tepee Sukkah. This would imply that in the above case a sukkah would be invalid if it contains anything less than 7 x 7 Tefachim of Kosher Sechach. However, in this Halacha, it is made clear that this is not fully accurate, and in truth there is no requirement to have 7×7 Tefachim of Kosher Sechach, under certain conditions, as will now be explained.]

The law: It is possible for a Sukkah to remain Kosher so long as it has a minimum of more than 4×4 dimension of Kosher Sechach, and this Kosher Sechach provides majority shade for the Sukkah. For example, if the total dimension of the roof of the sukkah is 7 x 7 Tefachim, then if it contains over 4 x 4 Tefachim dimension of Kosher Sechach, then the sukkah is valid even if the remaining less than 3×3 Tefach is made up of empty space or non-Kosher Sechach material.[8] If, however, it contains more than 3×3 Tefach of empty space or non-Kosher Sechach material on the roof next to the 4×4 area of Kosher Sechach, then it is invalid.[9] In such a case it is invalid even if it contains 6.9 by 6.9 Tefachim of Kosher Sechach.[10] [From here it can be established that by a non-tepee shaped Sukkah, there must be a roof of 7×7 Tefachim dimension for the Sukkah to be Kosher, although from amongst that space, it is not required for that entire space to be made up of Kosher Sechach, and rather so long as it contains less than 3 Tefachim of non-Kosher Sechach in that space, or empty space in that space, it is valid.[11]]

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[1] See Michaber 632:1; Rama 631:10; Tur 631; Beis Yosef 631 and 632; M”A 632:3; Elya Raba 632:3

Background: See Ran, brought in Beis Yosef 631, that the Sechach wall of the teepee must be 17 Tefachim tall, ten for the height of the wall, and seven for the Sechach, hence implying that it must have seven [x7?] Tefachim worth of Sechach. However, see Beis Yosef in explanation of Rav Hamaggid on Rambam Sukkah 4:7 that according to some opininions [which the Rav Hamagid leans to agree with] there is never a need to have a 7×7 space of Sechach, and so long as it has a Tefach of Kosher Sechach it is valid if it contains a space of 7×7 Tefachim on the ground, and does not contain 3 Tefachim of invalid Sechach, or empty space, on top, such as by a tepee Sukkah. Practically, while the Rav Hamagid himself is stringent, and so seems to be the opinion of the Beis Yosef, in the Tur and Shulchan Aruch no one makes mention of a requirement for there to be 17 Tefachim of slanted wall made from Kosher Sechach. Nonetheless, the Rama ibid rules like the Ran that the slanted walls must be made of material that is Kosher for Sechach being that the walls are the Sechach, and the M”B 631:34 and Kaf Hachaim 631:55 rule that this applies even if it has a flat Tefach of Kosher Sechach. Thus, we see that the Poskim did accept the opinion of the Ran in regards to that a Tefach of Sechach does not suffice and one must include also the walls as Sechach. Vetzaruch Iyun according to this why also the condition of having 17 Tefachim of wall was not mentioned, although perhaps the Rama holds that the walls can serve both as Sechach and walls, Vetzaruch Iyun! Whatever the case, everyone agrees that a Sukkah of 7×7 remains Kosher so long as it contains more than 4×4 of Kosher Sechach [See Michaber 632:1] and hence we can conclude that so long as a Sukkah contains 4×4 Tefachim of Kosher Sechach it is valid even according to the Ran, and that he does not require a space of 7×7 of Kosher Sechach. However, in truth this is seemingly only correct according to the understanding of Elya Raba 632:3 who rules that so long as there is more than 4×4 of Kosher Sechach, then it is valid [under the Kosher Sechach] even if  there is more than 3×3 of non-Kosher Sechach. However, according to the M”A 632:3 who rules that it is only valid if in addition to having more than 4×4 of Kosher Sechach it also has less than 3×3 of non-Kosher Sechach, as only then is it nullified to the Kosher Sechach [Taz 632:3; M”B 632:10], then we see that a Sukkah is invalid so long as it does not contain 7×7 of Kosher Sechach, or an exact measurement of 7×7 roofing which contains less than 3×3 of non-Kosher Sechach, in which case we view it as nullified to the Kosher Sechach. Practically, we rule like the the M”A ibid. [P”M 632 A”A 3; Siddur Beis Shoeiva 632:11; M”B 632:8; Kaf Hachaim 632:12]  Vetzaruch Iyun why the Poskim don’t add the opinion of the Maggid Mishneh as recorded in the Beis Yosef ibid to prove like the Elya Raba that there is no requirement to have 7×7 Tefachim of Sechach, and that even one Tefach can suffice. Perhaps, however, the reason is because although a single Tefach of Kosher Sechach suffices, one is not allowed to have more non-Kosher Sechach than Kosher Sechach on the roof, or have 3 Tefachim or more of non-Kosher Sechach. Vetzaruch Iyun!

[2] Rama 631:10; Tur 631

[3] Michaber and Rama 631:10; See Background in previous footnotes!

[4] Michaber 631:10

The law if it contains a Tefach of slanted roof within three Tefachim: Some Poskim rule that it is valid and is considered similar to one flat Tefach, justa s we rule in 315 bregaridng an Ohel on Shabbos. [M”A 631:9; Elya Raba 631:9; See Admur 315:15] However, other Poskim argue on this. [See Kaf Hachaim 631:47]

[5] Rama ibid; See Ran, brought in Beis Yosef 631

How much slanted wall Sechach must one have? See Ran, brought in Beis Yosef 631, that the Sechach wall of the teepee must be 17 Tefachim tall, ten for the height of the wall, and seven for the Sechach, hence implying that it must have seven [x7?] Tefachim worth of Sechach. However, see Beis Yosef in explanation of Rav Hamaggid on Rambam Sukkah 4:7 that according to some opininions [which the Rav Hamagid leans to agree with] there is never a need to have a 7×7 space of Sechach, and so long as it has a Tefach of Kosher Sechach it is valid if it contains a space of 7×7 Tefachim on the ground for a height of ten Tefachim, and does not contain 3 Tefachim of invalid Sechach, or empty space, on top, such as by a tepee Sukkah. Practically, while the Rav Hamagid himself is stringent, and so seems to be the opinion of the Beis Yosef, in the Tur and Shulchan Aruch no one makes mention of a requirement for there to be 17 Tefachim of slanted wall made from Kosher Sechach. Nonetheless, the Rama ibid rules like the Ran that the slanted walls must be made of material that is Kosher for Sechach being that the walls are the Sechach, and the M”B 631:34 and Kaf Hachaim 631:55 rule that this applies even if it has a flat Tefach of Kosher Sechach. Thus, we see that the Poskim did accept the opinion of the Ran in regards to that a Tefach of Sechach does not suffice and one must include also the walls as Sechach. Vetzaruch Iyun according to this why also the condition of having 17 Tefachim of wall was not mentioned, although perhaps the Rama holds that the walls can serve both as Sechach and walls, Vetzaruch Iyun! Whatever the case, it would be logical to assume that one is required to have at least 7 Tefachim of Kosher wall material on each side of the tepee.

Other opinions: Some Poskim rule that a single Tefach of Kosher Sechach on the teeppe roof of the Sukkah suffices [and there is no need to have the walls be made of Kosher Sechach to join for a 7×7 dimension of Sechach], so long as it contains a space of 7×7 Tefachim on the ground, for a height of ten Tefachim. [Beis Yosef in explanation of Rav Hamaggid on Rambam Sukkah 4:7 that so is true according to some opininions which the Rav Hamagid leans to agree with]

[6] See Michaber ibid that the slanted wall can be lifted a Tefach from the ground to be valid with its Kosher Sechach

[7] See Michaber 632:1

[8] Michaber 632:1

The reason: The reason for why the Sukkah is Kosher in such a case is because the less than 3 Tefachim of empty space, or invalid Sechach, becomes nullified to the more than 4 x 4 Tefachim of Kosher Sechach,and ends up being considered like actual Kosher Sechach, to make up for the minimum 7 x 7 Tefachim dimension that is required. This is similar to a non-kosher food which became mixed in  majority of  kosher food in which case we rule that the nonkosher food becomes nullified and becomes actually Kosher [Levush 632:1, brought and vehemently negated in Taz 632:3] According to this reasoning, it’s understood that indeed a 7 x 7 dimension of Kosher Sechach is required, and it is simply that the non-kosher Sechach  joins to make up this dimension. [See Bikureiy Yaakov 632:6 that so is also evident from the ruling of the M”A 632:3, brought in M”B 632:8, who rules that even if by a 9.5 x 9.5 Tefachim dimension of a sukkah it is only valid if there is less than 3 x 3 Tefachim of empty space or nonkosher Sechach, which proves that in his opinion it does not suffice to simply have a 4 x 4 dimension of Kosher Sechach, and rather one must have the nonkosher Sechach, or empty space join for the minimum measurement of 7 x 7.] However, other Poskim completely negate this approach and simply state that since there isn’t a 3 x 3 Tefach dimension of invalid Sechach, or empty space therefore it is considered like nonexistent. [Taz ibid; See P”M 632 M”Z 3] According to this approach it seems that there is no requirement for there to be a 7 x 7 dimension of Kosher Sechach and rather so long as one has a 4 x 4 dimension of Kosher Sechach, and does not have more than a 3 x 3 Tefach dimension of empty space or non-Kosher Sechach, then it is valid.

[9] Michaber ibid that by a 7×7 Tefach Sukkah the Sukkah remains Kosher so long as one has more than 4×4 Tefachim of Kosher Sechach and the remaining [less than three Tefachim] is of non-Kosher Sechach

[10] M”A 632:3; P”M 632 A”A 3; Siddur Beis Shoeiva 632:11; M”B 632:8; Kaf Hachaim 632:12

The reason: As in such a case it contains less than 7×7 Tefachim of Kosher Sechach which is the minimum dimension required for a Sukkah. [M”A ibid; Poskim ibid] Now, although earlier we established that one only requires slightly more than 4×4 Tefachim of Kosher Sechach, this only applies in a case that the non-Kosher Sechach or empty space is nullified to the Kosher Sechach, or is considered non-existant, which is only applicable if it contains less than a 3×3 Tefach dimension. [See Bikureiy Yaakov 632:6]

Other opinions: Some Poskim question the above ruling of the M”A ibid and state that so long as the 9.5 by 9.5 Tefach Sukkah contains more than 4×4 Tefachim of Kosher Sechach, the Sukkah is valid and one may eat and sleep under the Kosher Sechach even if the remainder of the ceiling is non-Kosher Sechach and is greater than 3×3 Tefachim, as it is no different than the validation of a 7×7 Tefach Sukkah with slightly more than 4×4 Tefachim of Kosher Sechach. [Elya Raba 632:3] According to this approach, it is understood that there is no need for one to have 7×7 Tefachim of Kosher Sechach, and that so long as one has more than 4×4 Tefachim of Kosher Sechach, and has more Kosher Sechach then sunlight or non-Kosher Sechach, then it is valid. However, see Bikureiy Yaakov 632:6 who explains that even according to this opinion one needs part of the non-Kosher Sechach to join the Kosher Sechach for a total of a 7×7 dimension, and it is just that they rule that even more than 3×3 Tefachim of non-Kosher Sechach can join the Kosher Sechach to make up this dimension. However, this only applies if the non-Kosher Sechach is less than 4×4 Tefachim, as otherwise it is considered its own area of significance and cannot join the Kosher Sechach to make up its 7×7 dimension, and is hence invalid. [Bikureiy Yaakov ibid]

[11] This does not contradict the ruling by a Tzarif, in which we ruled that having a Tefach roof suffices, as there the slanted walls count as part of the 7×7 requried roof and Sechach.

[12] This follows the opinion of the M”A ibid, however, according to the Elya Raba, it would be valid even if the invalid material is stretched more than 3×3 Tefachim, so long as its less than 4×4 Tefachim.

[13] This follows the opinion of the M”A ibid, however, according to the Elya Raba, it would be valid even if the invalid material is stretched more than 3×3 Tefachim, so long as there is a 4×4 area of Sechach on the sunroof, which is the standard case for almost all sunroofs of vehicles.

[14] In which case it would be invalid even according to the Elya Raba ibid