✍️Using sheets as a wall:[1]
It is not proper to use sheets [whether of fabric or plastic] as material for a wall even if it is tied down well.[2] However, it is permitted to use sheets if one places poles within three Tefach of each other and hence uses Lavud to make an additional backup wall.[3] [According to all, Bedieved if one used sheets for a wall, then if they are tied down well that they do not move with the wind, the Sukkah is Kosher even if Lavud was not used.[4]]
Practically are Sukkos with plastic or cloth material used as walls initially valid?[5]
If one places string or poles to perform Lavud to make three walls in addition to the plastic fabric walls, then even initially it is valid according to all. However, if Lavud is not being used, then one should not use such a Sukkah being it is possible that the plastic material walls will become loose and move with the wind. However, from the letter of the law, if the plastic does not move with the wind, it is valid. Furthermore, some Poskim[6] rule that it is even initially permitted to use plastic sheets if they are tightly attached as it is not possible to move with the wind.
How far must the sheet/plastic walls move with the wind to be considered problematic?[7]
If the wind can move it even slightly back and forth then it is invalid, even if the wind is unable to make it fall completely to the ground. [Some interpret this to mean as follows:[8] If the common wind can blow the sheet walls a distance of three Tefachim in a way that it invalidates the wall, then it is invalid. For example, if it can blow it three Tefachim, upwards from the ground, or three Tefachim away from the Sechach, or that it creates a stomach of three Tefachim deep in a way that it does not contain ten Tefachim of wall within three Tefachim of width, then it is invalid even when the wind does not blow.]
✍️ From the Rav’s Desk: Do I Need Lavud Strings on My Sukkah? When Are They Required and How Are They Made?
Question:
I see many Sukkos that have strings or wires wrapped around the walls. Some people tell me it is called “Lavud.” I am confused about a number of things: Does every Sukkah need these strings? When are they necessary? How are they installed? How high do they need to reach? How much space may there be between the strings? And does the string need to be made from a kosher material, or can it even be made from plastic?
Answer:
No, not every Sukkah needs Lavud strings.
Lavud is most commonly used as a backup wall for Sukkos that use fabric or plastic sheet walls, since such walls may move in the wind. By placing ropes, wires, poles, or strings within three tefachim (less than approximately 23 cm) of each other, for a total height of ten Tefachim (80/100 cm) Halacha views the gaps as closed and considers it a valid wall.
The strings may be made from virtually any material, including ordinary rope, cord, nylon, or plastic string. They do not need to be made of a material kosher for Sechach. They simply need to be strong enough not to snap or become untied in a normal wind.
Explanation
What Is Lavud?
Lavud is a halachic principle that states that whenever there is a gap of less than three Tefachim between two items that are parallel to each other, the gap is considered closed. Chazal therefore allow one to create a halachic wall by placing poles or strings close enough together that each gap is less than three tefachim.
For example, one can create a wall using horizontal ropes with less than three tefachim between each rope, or using vertical poles with less than three tefachim between each pole.
Why Do People Put Strings Around Their Sukkah?
The most common reason is because the walls are made from cloth or plastic sheets. The Shulchan Aruch states that one should not ideally make Sukkah walls entirely out of sheets because they may loosen and move in the wind. Even if tied well, one cannot always guarantee that they will remain perfectly secure for the entire Yom Tov. Therefore, the accepted practice is to add Lavud strings or poles as a backup wall. This way, even if the sheet moves, the halachic wall remains intact because of the Lavud.
Does Every Sukkah Need Lavud?
No. If your walls are made from solid wood, metal, brick, rigid panels, or another sturdy material that does not sway in a normal wind, then no Lavud strings are needed.
Lavud is generally used when:
- The walls are fabric.
- The walls are plastic sheets.
- One wants an extra level of halachic certainty.
- One is constructing a lightweight portable Sukkah.
How Many Strings Are Needed and How High Must They Reach?
The purpose of the strings is to create a halachic wall using the principle of Lavud. Accordingly, the Lavud strings must create a wall that reaches a height of ten tefachim, which is approximately 80-100 cm depending on the opinion followed.
- According to the measurements of Rav Chaim Na’eh, ten tefachim equals approximately 82 cm.
- According to the Chazon Ish, ten tefachim equals approximately 98.2 cm.
Practically, one should ideally ensure that the Lavud reaches at least 100 cm from the ground in order to satisfy all opinions, and all individuals who may wish to use ones Sukkah.
Likewise, the bottom string should begin within three tefachim of the ground, and the spacing between every string should remain less than three tefachim (approximately 24 cm according to Rav Chaim Na’eh).
How Much Space May There Be Between the Strings?
The maximum gap is less than three tefachim between every string. Practically, based on the ruling of the Grach Nae’eh, this is approximately 23 cm between each string to ensure the gap remains less than three tefachim according to all opinions.
Can I Use One Long String Around the Entire Sukkah?
Yes. There is no need to cut the string for every wall. A single continuous rope may wrap around all three walls of the Sukkah.
What Material Must the Strings Be Made Of?
This is perhaps the biggest misconception. There are no special material requirements for Lavud strings. The walls of a Sukkah do not follow the same rules as the Sechach. Accordingly, even materials completely invalid for Sechach may be used for the walls and for Lavud. They may be made from:
- Plastic cord
- Nylon rope
- Twine
- Metal wire
- Regular rope
- Virtually any durable material
The only requirement is that it be strong enough not to break or become untied in an ordinary wind.
Can One Build an Entire Sukkah Using Only Lavud Strings?
Not always. The Magen Avraham, as brought in the Mishnah Berurah, rules that one may create an entire Sukkah using horizontal or vertical Lavud alone only if the Sukkah contains four walls. In such a case, all four walls may be constructed from strings, ropes, or poles placed less than three tefachim apart from each other. However, if the Sukkah contains only the standard three walls, one may not initially create all three walls using Lavud alone. Rather, two walls must be complete walls containing a solid length of at least seven tefachim, without relying on Lavud. In addition, the third wall must contain a post that is wider than one tefach. One cannot simply create that third wall using many narrow strings or poles and rely entirely on Lavud. Accordingly, the Lavud strings found on most commercially manufactured canvas Sukkahs are generally not serving as the primary walls. Rather, they serve as a backup wall in case the canvas or plastic wall moves in the wind. This is a valid and recommended use of Lavud even in a standard three-walled Sukkah.
Common Lavud Layout
| Item | Requirement |
| Bottom string | Within 3 tefachim, 23 cm. of the ground |
| Space between each string | Less than 3 tefachim, 23 cm |
| Total wall height created | 10 tefachim, 82 cm or more |
| Material | Any durable material |
| Must be kosher for Sechach? | No |
| Used mainly for | Sheet and fabric walls |
Practical Takeaway
- If you have rigid walls that do not move in the wind, you generally do not need Lavud strings.
- If your Sukkah uses fabric or plastic sheet walls, then adding Lavud strings is highly recommended and is often the standard method used to ensure the walls remain kosher according to all opinions.
- The strings may be plastic, nylon, metal, or any other durable material, provided that the space between them is less than three tefachim and they reach a halachic wall height of ten tefachim.
Sources:
- Regarding making Sukkah walls through Lavud: Magen Avraham 630 in Hakdama; Mishnah Berurah 630:7. Piskeiy Teshuvos 630:2; See Shabbos 97
Other opinions: Some Poskim rule that Lavud only works vertically and not horizontally. [Maharsha, brought and negated in M”A ibid] Some Poskim rule that a Sukkah wall may never be made using Lavud of narrow sticks within three Tefach of each other. [Chazon Ish 75:12]
- Regarding use of Lavud as a backup to fabric and plastic walls: Michaber 630:10; Piskeiy Teshuvos 630:9
- Regarding walls being valid even from materials invalid for Sechach: Michaber 630:1; Biur Halacha 630:1
- Regarding the practical measurement of ten tefachim: See Shiureiy Torah p. 249 that an Ama Sochekes is 49 cm., and accordingly a Tefach Sochakos is 8.17 cm [i.e. 1/48 of a cm times 8.] and by the Shiur Sukkah of 7×7 one should measure with an Ama Sochakos, and the same would apply here Lechumra. Thus, its exact Shiur is 81.7 cm; See also M”B 633:2 and Shaar Hatziyon 633:2 that by Sukkah we follow the stringent approach in the dimensions, either Dochakos or Sochakos, and by the 7×7 dimension we follow Sochakos, and the same would apply here by the ten Tefach dimension; See also Midos Vishureiy Torah pp. 48-57 regarding Ama Sochakos and Dochakos; Piskeiy Teshuvos 633:1; Minchas Chinuch Mitzvah 325 who rules that by Tefachim we don’t apply the extra Dochakos or Sochakos, and this is only done by Amos
Other opinions-Chazon Ish: According to the Chazon Ish, the measurement is 98.2 cm following the 9.82 measurement of Tefach Sochakos. [See Piskeiy Teshuvos ibid]
- Regarding the practical measurement of three tefachim: See Shiureiy Torah p. 249 that an Ama Dochakos is 47 cm. [as opposed to 48 for a regular Ama], and accordingly a Tefach Dochakos is 7.83 cm [i.e. 1/48 of a cm times 8, deducted from 8 cnetimeters] and by the Shiur Sukkah of 7×7 one should measure with the stringent approach of an Ama Sochakos, and the same would apply here Lechumra to measure the three Tefachim as Dochakos. See also M”B 633:2 and Shaar Hatziyon 633:2 that by Sukkah we follow the stringent approach in the dimensions, either Dochakos or Sochakos, and by the 7×7 dimension we follow Sochakos, and the same would apply here by three Tefachim; See also Midos Vishureiy Torah pp. 48-57 regarding Ama Sochakos and Dochakos; Piskeiy Teshuvos 633:1 writes that its 23.4 according to Grach Nah, when taking into account the Dochakos according to Chazon Ish, as he explains there in footnote 2
Other opinions-Chazon Ish: According to the Chazon Ish, the measurement is 28.26 cm following the 9.42 measurement of Tefach Dochakos. [See Piskeiy Teshuvos ibid]
[1] Michaber 630:10; Piskeiy Teshuvos 630:9
[2] The reason: Being that it is difficult to ascertain that the sheets will not move with the wind, as even if one ties them well, occasionally the ropes tear unnoticeably, and he ends up having a wall that cannot stand in face of a common wind. [Michaber ibid]
[3] The reason: As in such a case even if the sheets move with the wind the wall remains Kosher due to the poles which are Lavud.
[4] Aruch Hashulchan 630:32
[5] Piskeiy Teshuvos 630:9
[6] Salmas Chaim 253; Kinyan Torah 4:70; Mishneh Halachos 5:77; Moadim Uzmanim 1:84
[7] M”B 630:48
[8] Chazon Ish 77:6; Piskeiy Teshuvos 631:9