Once your insulation is in place, you want it to stay in place. The problem with some sprayed foams -- or any other things you can imagine stuffing into your walls to keep the heat in and the cold out, or vice versa -- is that they tend to settle into a little mass of compacted sludge at the bottom of your wall cavity. That tends to defeat the purpose. All it takes to hold Air Krete up is a lattice as flimsy as chicken wire. And once the material sets, it doesn't settle. Its initial dried form is the form it keeps for many, many years.