Can you use fabric made from plant fibre for s'chach?

Question

Can you use fabric made from plant fibre (eg. hemp, jute, burlap, hessian etc) for s'chach?

As far as I understand, it grows from the ground, it isn't made into a keli so shouldn't be mekabel tumah and it isn't still connected to the ground, but I know that paper and cardboard aren't ok because they have been processed so much, so not sure if that falls into the same problem?

If it is allowable, would it be considered not ideal and are there any restrictions on it - obviously it would need to be more shade than sun, but is there anything else?

Answer 1

Per Shulchan Aruch, Orach Chaim 629:3, it would be invalid for s'chach at even an earlier stage, when it's been "pounded and combed." Taz there says that it's barred derabanan, because (1) it's ready to be spun into thread (at which point it will be mekabel tum'ah), (2) it doesn't look like its original form (this is the point you were making about paper and cardboard being "processed so much"), and (3) it's usable as stuffing for pillows.

On top of that, even if somehow we could argue that these considerations would apply only to flax (the subject of the halachah there), there's also the point that you can't use something that once was a keli and now is broken (ibid. 629:2). So not only would the pieces have to be less than 3x3 fingerbreadths (as in Danny's answer), they'd have had to be woven as pieces less than that size in the first place.

Answer 2

See Mishna in Keilim 27:1 that cloth is mekabel tumah once it's as large as 3 fingerbreadths by 3 fingerbreadths. So your plant fibre s'chach would have to consist of tiny pieces of less than an inch squared.

הַבֶּגֶד מִטַּמֵּא מִשּׁוּם חֲמִשָּׁה שֵׁמוֹת. הַשַּׂק, מִשּׁוּם אַרְבָּעָה. הָעוֹר, מִשּׁוּם שְׁלֹשָׁה. הָעֵץ, מִשּׁוּם שְׁנַיִם. וּכְלִי חֶרֶס, מִשּׁוּם אֶחָד. כְּלִי חֶרֶס מִטַּמֵּא מִשּׁוּם כְּלִי קִבּוּל. כֹּל שֶׁאֵין לוֹ תוֹךְ בִּכְלֵי חֶרֶס, אֵין לוֹ אֲחוֹרָיִם. מוּסָף עָלָיו הָעֵץ, שֶׁהוּא מִטַּמֵּא מִשּׁוּם מוֹשָׁב. וְכֵן טַבְלָא שֶׁאֵין לָהּ לִזְבֵּז, בִּכְלֵי עֵץ, טְמֵאָה, וּבִכְלֵי חֶרֶס, טְהוֹרָה. מוּסָף עָלָיו הָעוֹר, שֶׁהוּא מִטַּמֵּא מִשּׁוּם אֹהָלִים. מוּסָף עָלָיו הַשַּׂק, שֶׁהוּא מִטַּמֵּא מִשּׁוּם אָרִיג. מוּסָף עָלָיו הַבֶּגֶד, שֶׁהוּא מִטַּמֵּא מִשּׁוּם שָׁלֹשׁ עַל שָׁלֹשׁ:rlm;

Cloth is susceptible to five categories of uncleanness; Sack-cloth is susceptible to four; Leather to three; Wood to two; And an earthenware vessel to one. An earthenware vessel is susceptible to uncleanness [only] as a receptacle; any earthen vessel that has no inner part is not susceptible to uncleanness from its outer part. Wood is subject to an additional form of uncleanness in that it is also susceptible to uncleanness as a seat. Similarly a tablet which has no rim is susceptible to uncleanness if it is a wooden object and insusceptible if it is an earthenware one. Leather is susceptible to an additional form of uncleanness in that it is also susceptible to the uncleanness of a tent. Sack-cloth has an additional form of uncleanness in that it is susceptible to uncleanness as woven work. Cloth has an additional form of uncleanness in that it is susceptible to uncleanness when it is only three by three fingerbreadths.

In Mishna 28:7 we learn that this excludes the fringes.

This is coded by the Rambam in Mishneh Torah, Keilim Ch. 22