Loose-fill (including Cellulose)
Loose-fill materials can be blown into attics, finished wall cavities, and hard-to-reach areas. They are ideal for these tasks because they conform to spaces and fill in the nooks and crannies. They can also be sprayed in place, usually with water-based adhesives. Many types are made of recycled materials (a type of cellulose) and are relatively inexpensive.
General procedure for retrofits in walls:
- Drill holes in wall with hole saw, taking firestops, plumbing pipes, and other obstructions into account. It may be desirable to drill two holes in each wall cavity/joist section, one at the bottom and a second at the top for both verification and top-off.
- Pump loose fill into wall cavity, gradually pulling the hose up as the cavity fills.
- Cap the holes in the wall.
Read more about this topic: Building Insulation Materials