“Foster” Foamseal 30-45 is a gray vapor barrier sealant designed for use with rigid thermal insulation including polystyrene foam.  It remains flexible and tough in joints and will not shrink or crack during repeated cycles of high and low temperatures.  Seals the joints of cellular glass and other insulations against the entrance of moisture.  

When used as a bedding compound and joint sealant, 30-45 provides additional protection to the blocks of insulation and protects metal equipment against corrosion.  Damage to the insulation due to migration of moisture is minimized.  Foamseal is water and weather resistant and is often used as a sealant in the laps of metal jacketing and as a flashing compound where structural parts must penetrate and insulation surface.