Attic basics in Centennial-area houses

Common insulation
Loose-fill fiberglass or cellulose, sometimes over older batts
How smoke gets up there
Recessed lights, bath fans, the attic hatch, plumbing and wiring holes, and around the chimney
When odor gets worse
Warm afternoons and whenever the house is depressurized by exhaust fans
Usual fix
Remove affected insulation, clean and seal, then reinsulate

Why insulation can't usually be cleaned

Loose-fill insulation is a mass of fine fibers with enormous surface area, built to trap air. That same property lets it trap smoke particles and odor compounds. There is no practical way to wash it, and deodorizing it in place tends to give temporary results at best.

Summer sun heats an attic well above outdoor temperatures. Heat drives odor compounds out of the insulation, and the house below draws that air in through every ceiling penetration, especially when bath and kitchen fans run. That is why some owners find the smell is fine in the morning and noticeable by late afternoon.

Removal is usually done with a large vacuum system that pulls insulation through a hose to a truck or collection bags outside. After that, the roof deck, trusses and top plates are inspected, cleaned of soot where needed, and sometimes sealed with an odor-blocking coating before new insulation goes in.

Signs the attic is or is not the problem

Points to the attic

  • Odor strongest in upstairs rooms or near ceiling lights
  • Smell worse on warm afternoons
  • Dark streaks in insulation around fixtures and the hatch
  • Fire or heavy smoke reached the top floor

Points elsewhere

  • Smell strongest when the furnace runs, which suggests ducts
  • Odor near one wall, which suggests a wall cavity
  • Smell in closets with smoky clothing still inside
  • Basement odor after a lower-level fire

What a typical attic remediation looks like

  1. Inspect and photograph

    The attic is inspected from the hatch and by walking on framing where safe, with photos of the insulation depth and soot pattern.

  2. Protect the house below

    The hatch area and rooms below are covered to keep dislodged soot from falling into living space.

  3. Remove insulation

    Affected insulation is vacuumed out and disposed of. Batt insulation is bagged by hand.

  4. Clean and seal framing

    Soot is cleaned from trusses and roof deck, and an odor-sealing coating is applied if needed.

  5. Air-seal and reinsulate

    Gaps around fixtures and penetrations are sealed before new insulation is installed to the specified depth.

Common questions

Will new insulation be better than what I had?

Replacement is usually to a similar level, though code requirements for the repaired area may apply. If you want to add more, ask for the extra to be priced separately from the insurance scope.

General information for Centennial, not a quote or professional advice. In an emergency, call 911.