Maximum length of CSST not supported by a listed method shall be supported on a roof top

Maximum length of CSST not supported by a listed method shall be supported on a roof top

• A. 12 inches
• B. 24 inches
• C. 60 inches
• D. 30 inches

Answer: (D)

CSST that isn’t secured by a listed support method must be supported at fairly close intervals to prevent movement and damage. On a roof, this means the maximum distance the tubing can run without a supported attachment is 30 inches. The idea is to minimize movement from wind, thermal expansion, or foot traffic near the installation, which could cause kinks, abrasion, or punctures over time. If you do have a listed method for supporting CSST on a roof, you follow the spacing and requirements specified by that listing. But in the absence of such a listed method, you use the 30-inch spacing as the default to keep the installation safe and the gas path intact. Shorter or longer spacings aren’t allowed unless the listed method explicitly permits them, and on rooftops those 30 inches help guard against damage where the tubing is more exposed.

CSST that isn’t secured by a listed support method must be supported at fairly close intervals to prevent movement and damage. On a roof, this means the maximum distance the tubing can run without a supported attachment is 30 inches. The idea is to minimize movement from wind, thermal expansion, or foot traffic near the installation, which could cause kinks, abrasion, or punctures over time.

If you do have a listed method for supporting CSST on a roof, you follow the spacing and requirements specified by that listing. But in the absence of such a listed method, you use the 30-inch spacing as the default to keep the installation safe and the gas path intact. Shorter or longer spacings aren’t allowed unless the listed method explicitly permits them, and on rooftops those 30 inches help guard against damage where the tubing is more exposed.