Dense Pack Cellulose Vs. Foam Insulation

Dense Pack Cellulose

• Dense pack cellulose is made from reconstituted wood fibers and recycled newspapers. This makes it a good choice for those who want to use an environmentally friendly insulation product. Cellulose is known for its ability to stop air from seeping in and for its sound insulation qualities. Many manufacturers treat the cellulose with borates to increase its fire retardant and insect repellent properties. Cellulose wet sprays are blown on to insulate open wall cavities and around ducts and pipe works. The wet-blown technique will perform very well at preventing and sealing off drafts. While cellulose can be used in a dry application, dry cellulose has a tendency to fall and settle because it does not adhere to surfaces as well.

Cellulose Cautions and Considerations

• One downside to dense pack cellulose is that it can retain moisture. Installers must allow sufficient time for drying, especially in situations where the wall or surface will be closed off after the cellulose insulation is applied. This will help prevent any moisture build-up. If you live in a moist and humid climate, cellulose may not be your best choice. Moisture could build-up and lead to mildew and mold development in between walls and other surfaces. Mold and mildew can cause reactions and exacerbate discomfort for anyone in the home who suffers from asthma or allergies.

Foam

• Foam insulation comes in panels and spray-on applications. Panels are most often used for commercial building projects for wall and electrical work insulation. Spray foam is used for both commercial and residential applications. Spray foam varieties are based on weight. For example, three-pound foam is used for roofs. Two-pound is used for exterior walls and half-pound foam is used underneath sheathing for roofs as well as for exterior walls. Unlike dense pack cellulose, spray-on foam is installed by professionals and is not a good candidate for a do-it-yourself project. Sprays contain lots of water and requires expert skills in knowing how to use just the right techniques for application. If mistakes are made, such as applying too much foam and not allowing it to dry properly, the moisture can crack walls. For these reasons, foam panels and sprays are usually sold to members of the building trade and HVAC professionals, only.

Foam Cautions and Considerations

• Understand that the denser and heavier the foam is in terms of weight -- the more expensive it will be. Denser foams have a higher R-rating, which is the rating used to measure the density on a per pound basis. For example, a less dense, one-half pound foam might have an R-rating of 3.5, and a two-pound foam with a higher density might have a rating of 6.0. The lighter foam may be appropriate for a garage walls, and foam with a higher R-rating might be better for insulating roof work. Always ask your installer to inform you about the pros and cons of various weights and R-ratings of the type of foam that is being recommended so you make the right choice for your insulation job.