Is a Sukka Made of Canvas Kosher?

Ask the Rov: The Sukka market these days is full of various types of fabric sukkas. How can I ensure that my canvas sukka is kosher?

By Rabbi Chaim Hillel Raskin, Rov of Anash in Petach Tikvah.

The Gemara teaches that the sukka’s walls need to be able to stand in a common wind to be valid. Therefore, if one makes walls out of flimsy materials—such as tree branches or fabric—he must tie them so the wind doesn’t cause them to sway.

The rishonim quote this halacha but don’t provide a clear definition of how much movement is problematic. Some later poskim explain that only if the wall sometimes sways more than 3 tefachim (9.45”)—exceeding the threshold of lavud—is it considered unable to stand in the wind. Others understand from the Gemara that even swaying minimally—unless hardly discernable—removes its halachic status as a wall.

The sturdiness of the walls is measured based on the standard wind in that location. When the sukka isn’t open to the wind, some say the barometer is whether the walls would sway if the area was open to the wind.

Shulchan Aruch quotes an additional concern with cloth walls—they can easily become untied thereby invalidating the sukka without the owner noticing. It is therefore recommended to create another set of halachic walls by adding horizontal “lavud” sticks or strings around the lower portion of the walls. When there is less than 3 tefachim between one and the other, they are considered halachically as one continuation.

Three or four of these reinforcements—depending on their width—are sufficient to create “walls” up to a height of 10 tefachim (31.5”). More than that isn’t necessary since these walls are considered to halachically continue until the roof by the principle of gud asik. (If using ropes or cables, it is important that they be taut; otherwise their purpose is defeated.)

The fact that canvas sukkas are sold and used isn’t proof that they are halachically valid. Some contemporary poskim argue that today’s canvas sukkas are created to fit snugly, thus there is less concern that it will sway and detach, though every case must be judged individually.

In practice, one should ensure that the sukka walls are tight and kosher according to all opinions. It is appropriate to add the lavud, but the sukka is kosher as long as the walls don’t sway and are tied down well. If one finds himself in a place with only a canvas sukka that sways slightly, he may use it if the walls are tied well relying on the lenient opinions.

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