air krete insulation is fire proof, environmentally safe and non-toxic free of cfc's & formaldehyde, mold resistant & pest resistant because air krete has a drying effect on the pests. air krete application can completely fill all cavities including door and window casings and has a great r value of 3.9 per inch. there is 0% shrinkage and has acoustical properties - air krete acts like a blanket that deadens noise from outside the house. air krete was used for this purpose in the neil young sound studios in santa cruz and musicians institute in hollywood ca.