How to add cellulose insulation to your attic

Insulation contractor Rick Davenport shows Bob how they install wet-spray cellulose insulation into open walls. The material is typical cellulose insulation, simply recycled newspaper. It's the installation system that is unique. Small jets of water moisten the insulation as it leaves the nozzle of the blower hose. The damp cellulose sticks to the studs and exterior sheathing, completely filling the wall cavity. The moisture will dry before the interior drywall is installed, so it doesn't harm the wall or affect the insulation value of the material. A large rotating brush, called a stud scrubber, removes excess material and cleans the inside face of the stud. In the ceiling, a blown-in-insulation is used. Plastic netting has been stretched along the bottom surface of the ceiling joists to support the material. The end of the blower hose is inserted through the netting to fill the cavity. Instead of adding water as the cellulose leaves the hose, an adhesive binder is mixed with the cellulose before it leaves the hose. The binder helps achieve a controlled density that provides a uniform insulation level of R-3.7 per inch, which comes to R-37 in this 10-inch cavity.