Sealants

Sealants, as the name applies, are used to stick materials together and also to block airflow. All caulking (a sealant to seal joints or seams against leakage) materials must have at least a minimum of 20 years of life expectancy before use. Acceptable sealants include (but not limited to): 

1. Foam sealants that meet ICC ES 377 and ASTM C1642-07 such as: 
   1. 1-part urethane foam, low CFC (e.g. Great stuff, Pur-fil, Insta-foam, or equivalent). 
   2.  1-part urethane fire-block foam rated for sealing gaps in wood fire blocking. 
   3.  2-part urethane foam kits 1.75pcf density, 2-part Flame Spread 25 foam kits 1.75pcf. 
2. Siliconized latex sealants meeting ASTM C834, 
3. Silicone, 1-part gun grade urethane, and other elastomeric sealants meeting ASTMC 920, (“Silicone” refers to 100% silicone caulk, clear or pigmented—not acrylic) 
4. Water-based duct sealant meeting UL 181A-M, UL 181B-M (“RCD #6” or equivalent) 
5. Sealants rated for contact with chimneys and combustion vents such as: 
   1.  Non-combustible fire barrier caulk or furnace cement meeting ASTM E 136. 
   2.  Silicone high temp RTV listed for use on gas vents to 500 degrees F, meeting ASTM C920.