For information:

Why have over 5 MILLION Canadian windows been sealed with “Blue Goo”?

What is “Blue Goo”?

Envelope Sealant a.k.a. “Blue Goo” is an elastomeric co-polymer sealant which acts as a primary
barrier to moisture and air penetration at the window to wall interface.  The self-curing, flexible nature of Envelope Sealant allows for shifting and movement during settling, while maintaining a
permanent seal. The product bonds directly to any substrate including OSB, plywood, fiberglass, concrete and even styrofoam (Type II).


“Blue Goo” can be applied at temperatures ranging from -25° to 30° Celcius and does not require the use of a primer.