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How do AttiCat bag calculations work?

Short answer

Choose the chart that matches the market and bag, select an exact labeled added R-value, divide attic area by that row’s maximum coverage per bag, and round up; also honor a stated minimum bag rate.

The U.S. and Canadian coverage cards are different. The calculator refuses interpolation so a plausible-looking R-value cannot create an unsupported coverage number.

  • The result is an added product-label R-value, not a measured whole-assembly rating.
  • Installed minimum thickness is part of the label result.
  • Verify the current bag and card before installation.

Formula or decision boundary

whole bags = ceiling(area ÷ label maximum coverage); U.S. rows also check ceiling(area ÷ 1,000 × minimum bags/1,000)

Label behavior

Label behavior
ChoiceAccepted?Reason
Exact row on matching market cardYespublished coverage
R-value between rowsNowould require interpolation
U.S. row for Canadian bagNodifferent market label
Current matching bag labelYesverify at purchase

Use the answer

  1. Measure net attic area

    Use the insulated ceiling-plane area and separate spaces with different assemblies.

  2. Select market and exact row

    Match the bags and choose only a published label R-value.

  3. Install to both controls

    Meet required bag count, maximum coverage, and minimum installed thickness on the label.

Safety and scope

  • Inspect and air-seal before adding material.
  • Do not cover prohibited fixtures or disturb suspect insulation.

Sources and scope

Source links reviewed July 16, 2026. A review date is not the document's publication date.

  1. Owens Corning: AttiCat Expanding Blown-In Insulation SystemUnited States · manufacturer data sheet

    Calculator accepts only labeled table R-values and rounds the label bag requirement up.

  2. Owens Corning Canada: AttiCat Expanding Blown-In Insulation System and coverage chartCanada · manufacturer data sheet

    The official product page publishes the coverage chart and links the identified Coverage Card; use the Canadian label, never the U.S. table, and verify the current bag at purchase.

  3. ENERGY STAR: Attic InsulationUnited States · government guide

    Air leaks and moisture conditions should be addressed before insulation is added.

  4. Natural Resources Canada: Keeping the Heat In — Roofs and atticsCanada · government guide

    Follow product labels for bag count and settled depth; do not disturb suspected vermiculite.