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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 charts are different. The calculator accepts only published rows, so it will not guess a coverage number between R-values.

  • 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.

How this answer is worked out

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

Put it into practice

  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.

Before you start

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

Sources and notes

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.