Last year I used bamboo mats as sechach (covering) for my sukkah. However, some of it blew off during Sukkot. I was wondering if I can just tie it down with string. When I asked (and looked on the Internet), I got mixed replies.


In general, the key difference between the materials used for the walls of the sukkah and the sechach covering is that the walls can be made of any material, but the sechach needs to be a substance that (a) has grown from the ground, (b) is presently detached from the ground, and (c) is not susceptible to ritual impurity.

Generally speaking, once something has become a tool or has been modified for use, it is susceptible to ritual impurity and therefore invalid for sechach. However, simple branches or beams can’t become impure and may therefore be used for sechach.

As a safeguard, the rabbis decreed that, ideally, the sechach should not be supported (or kept in place) with materials unsuitable for sechach, lest one come to use those as actual sechach.1

However, one may rest the sechach on the walls of the sukkah itself, even though the walls may be made of materials that are invalid as sechach, such as stone or brick. There is no need for a safeguard in this instance, as it is well known that these materials cannot be used for sechach. Using brick or stone for a roof would be similar to a permanent dwelling, and a sukkah is specifically constructed as a temporary dwelling.2

Wind, Ropes and Zip Ties

In order for a sukkah to be kosher, it needs to be sturdy enough to withstand a regular wind. That means if an ordinary wind can potentially blow off the sechach, the sukkah is invalid even if the sechach is still there.3 Therefore, if the sechach is made from very light materials (such as some bamboo mats), it may be necessary to hold it in place.

Based on the above, the preferred option in this instance would be to either place a heavier object such as a 2x4 piece of wood (as it itself is unsusceptible to ritual impurity) over the sechach to weigh it down, or, alternatively, tie the sechach down with rope made of unprocessed reed grass or palm (a simple, natural twine that can be found in many hardware stores).

However, if the sechach will only blow off with an uncommonly strong wind, it need not be tied down for the sukkah to be kosher. If one still wishes to hold it in place as an added precaution, one can use any material.

In any case, one should not use nails to hold down the sechach, as that is too similar to a permanent structure.4

A Support to a Support

Although what directly supports the sechach needs to be something that isn’t susceptible to impurity, according to most opinions, including Rabbi Schnur Zalman of Liadi in Shulchan Aruch Harav,5 it is of no consequence that the object that supports the sechach or holds it in place is itself supported by something that is invalid as sechach. After all, the support for the sechach of every sukkah in the world is ultimately supported by the ground, which is invalid as sechach.

Sukkah Still Kosher

Although we discussed the preferred manner of how the sechach should be supported or held down, it must be stressed that after the fact, if one already supported the sechach with something that is susceptible to ritual impurity (or must do so because they had no other material to use6), one may sit in such a sukkah without hesitation.7

Let us conclude with wishes that G‑d soon shelter us in His “sukkah of peace”8 with the arrival of Moshiach.