Flexible Weather Sealing Foam Tape What is the expanding foam tape? Our expanding foam tape is a pre-compressed self-expanding PUR foam sealing tape impregnated with a fire resistant polymeric dispersion. Unlike regular expanding foam in a can, our Expanding Tape does not harden or crack. It remains permanently elastic, expanding and contracting as joints move, thus creating a flexible weather seal. Where is the expanding tape used? It is a versatile tape that has a wide range of uses, it is most commonly used for sealing construction joints (including moving joints) in areas such as; prefabricated concrete and other material, elements (including civil engineering), perimeter seals for fenestration (windows/doors), skylights, cladding panels and curtain walling. The tape withstands the long term stresses caused by UV light and driving rain. It can also be used as an aesthetic, air, draught or dust seal for internal joints. The vapour permeable joint sealing tape also possesses outstanding thermal and acoustic characteristics, as well as allowing for diurnal movement. Is Expanding Foam Tape waterproof? The tape provides a waterproof weather seal providing protection from general weather including wind driven rain. How long does it take to expand? The tape will start to expand as soon as it is unwound from the roll (this releases the compression that is applied when it is manufactured). As a general rule, maximum expansion is usually achieved within 24 hours. The speed of the expansion is determined by the ambient temperature during application and the temperature of the tape itself when it is applied. The cooler the temperature, the slower the rate of expansion