Open cell offers more sound buffering for soundproofing. R value is 3.5 per inch. It is not waterproof. It does not offer structure stability. At a 3.5 inch average, open cell completely seals the structure being sprayed. No insulation outperforms open cell except for closed cell spay foam. Closed cell offers a 100% moisture barrier. Adds structure stability. Thermal heat reduction is high. R value is 7 per inch. An inch and a half of closed cell, the structure is completely closed.