Halocho #1291 - Making tents on Shabbat

Making a roof on Shabbat is forbidden; even if it's a temporary flimsy roof.

A roof is defined as a cover, over an area of at least 1 Tefach (8 cm, 3") by 1 Tefach, and at least 1 Tefach of space underneath it.

For example, on Shabbat one may not put a netting over a baby's crib - to protect the baby from flies - since one is creating a roof over the crib.

However, one may extend an existing roof, if the roof was already stretched out at least 1 Tefach.

For example, one may roll up the netting over a baby's crib until the last Tefach, before Shabbat, and unroll it on Shabbat, since 1 Tefach was left unrolled. 

Even if the netting - when  rolled-up - was wider than 1 Tefach, it does not count towards the unrolled section. One needs 1 Tefach unrolled, besides for the width of the roll.

These Halachot apply to Yom Tov also.

Source: Kitzur Shulchan Aruch 80:77

Shabbat Shalom
- Danny
Thursday, 20 Adar-I 5774