Ceiling Blow-In Insulation Vs. Roll Insulation

Efficiency

• Both rolls and blown-in insulation offer thermal resistance, or R-value, in your ceiling. The thickness of the roll batts and the depth to which you apply blown-in insulation will determine the amount of R-value in the ceiling. As the thickness increases, so does the insulating factor.

Tools

• To install roll insulation, you'll need a utility knife to cut the batts, a tape measure and a staple gun. For blown-in insulation, all you need is a blower/hopper rig that you can rent from a construction rental store. Some lumber and hardware stores allow you to use their rig if you purchase the insulation from them.

  In addition to the blower/hopper, you'll need an assistant to feed the insulation into the rig while you operate the blower hose.

Installation

• Installing roll insulation involves measuring and cutting individual batts to fit between the ceiling joists or the attic rafters. You'll fold out the attached paper strips over the adjacent joists and secure the strips to the joists with a staple gun. You will cut around can lights and stovepipes, leaving at least 2 inches free on all sides.

  Before you blow in insulation, you'll block around eave vents, can lights and any heated vent pipes that may extend through the attic. Block by building simple cubicles out of drywall or plywood to fit around the cans or the pipes to prevent the loose fibers from making contact with these heat-related items. Your local building code may specify a required distance from the heat-related items to the insulation.

  Take safety precautions when installing insulation. Wear gloves, disposable coveralls and protective eyewear when installing either type. In addition, wear a wide-brimmed hat and a full respirator when installing blown-in insulation. The hat brim offers better visibility from fibers falling in front of your face.

Considerations

• Blown-in insulation offers the tightest seal in corners and small stud spaces, but it isn't always feasible. If you're insulating a small attic, with restricted space to move around, opt for blown-in insulation.

  If your roof has a truss system, you may have to blow in insulation because it can be tough to maneuver around the truss rails to install batts.

  In vaulted ceilings, with only stud space, use roll insulation, installed before you attach the ceiling drywall panels.