Cellulose insulation is made from recycled paper fibre treated with borate minerals that make it resistant to fire, mold, and insects. It delivers about R-3.7 per inch, flows into irregular spaces, and is one of the most economical and ecological ways to insulate large areas. It has been used in Quebec homes for decades and remains the best value available for open attics.
For an open attic, we run a hose from the blowing machine in our truck up to the attic hatch. One of our crew members fluffs and loads blocks of cellulose into the hopper, while another crew member in the attic distributes the cellulose evenly across the floor to the depth required, typically 12 to 16 inches to reach R-41 to R-60. Before blowing, we prepare the attic properly:
Install baffles at the eaves so soffit ventilation stays open
Build a dam around the hatch and insulate the hatch cover
Block off and clear recessed lights, exhaust fans, and chimneys
Depending on your existing insulation and whether it’s been damaged, has settled over time, or shows signs of vermin or other critters, an attic top-up may be applicable. New cellulose insulation can be blown on top of existing insulation, even of other types, in order to “top up” the attic to the desired R-value.
Isolation Majeau’s professional teams will be able to tell you if your attic is applicable for a top-up, or if a complete removal and re-insulation of the attic space is recommended.
Cellulose, like any fibrous insulation, does not stop air leakage by itself in loose-fill form, which is why it’s recommended to pair with air sealing. It must also be kept dry; if your attic has a roof leak or ventilation problem, that needs to be addressed first rather than burying it.
Excellent cost per unit of R-value, especially in attics
Roughly 85 percent recycled content, with low embodied energy
Made from locally-recycled newsprint, and manufactured in Canada
Fills gaps and irregular spaces that batts leave open
Good acoustic performance
Borate treatment resists fire, mold, and pests
Dense-pack cellulose is a different installation technique. Instead of being blown into an open space, cellulose is blown into closed wall cavities through small holes in a membrane to a specified packed density. When densely-packed in this way, cellulose insulation doesn’t settle over time, and it packs firmly around wiring, plumbing, and framing. This type of installation is extremely efficient, provides a very high R-value, and is generally done in new construction or renovations where the wall or ceiling cavities are fully exposed.
Some insulation contractors will cut corners in your attic by skipping proper ventilation, blowing over problem areas, or charging extra for proper attic hatch cribbing. Isolation Majeau offers a complete package for every attic we insulate, with proper ventilation, baffles, and attic hatch work included in every job.
Our professional teams ensure consistent depth throughout your attic with no low spots. Whether you’re looking for a full, new attic install or just a top-up of your existing insulation, we can help!
Our Service Areas
Our Certifications
