Mesh Cubicle Curtains

What is the mesh requirement for cubicle curtains in hospitals?

This only applies to healthcare occupancies and the distance of the sprinkler from the mesh is just as important as the commonly known 18" rule.  Please see the code references below.

NFPA 101, Life Safety Code^®, 2000 Edition

19.3.5.5*

Newly introduced cubicle curtains in sprinklered areas shall be installed in accordance with NFPA 13, Standard for the Installation of Sprinkler Systems.

Annex A.19.3.5.5

For the proper operation of sprinkler systems, cubicle curtains and sprinkler locations need to be coordinated. Improperly designed systems might obstruct the sprinkler spray from reaching the fire or might shield the heat from the sprinkler. Many options are available to the designer including, but not limited to, hanging the cubicle curtains 18 in. (46 cm) below the sprinkler deflector; using 1/2-in. (1.3-cm) diagonal mesh or a 70 percent open weave top panel that extends 18 in. (46 cm) below the sprinkler deflector; or designing the system to have a horizontal and minimum vertical distance that meets the requirements of NFPA 13, Standard for the Installation of Sprinkler Systems. The test data that forms the basis of the NFPA 13 requirements is from fire tests with sprinkler discharge that penetrated a single privacy curtain.

NFPA 13, 1999 Edition, Cubicle Mesh Curtains

Appendix A

A-5-6.5.2.3 

The distances given in Table 5-6.5.2.3 were determined through tests in which privacy curtains with either a solid fabric or close mesh [1/4 in. (6.4 mm)] top panel were installed. For broader-mesh top panels — for example, 1/2 in. (13 mm) or greater measured on the diagonal — the obstruction of the sprinkler spray is not likely to be severe and the authority having jurisdiction might not need to apply the requirements in 5-6.5.2.3. 

A-5-6.6 

The 18-in. (457-mm) dimension is not intended to limit the height of shelving on a wall or shelving against a wall in accordance with 5-6.6.