Fiberglass vs Cellulose Insulation: Compare the Chart Rows

For each proposed product, record target R, bag mass, minimum installed depth, settled depth, maximum coverage per bag and minimum bags per 1,000 ft². Keep the rows separate. A material category does not provide a valid coverage curve for every brand.

Identify whether the chart is for open attic blowing, dense-pack cavities or another application. An attic row cannot automatically price or specify a wall-cavity installation. Both the thermal target and the installation method need to match the chart.

For an arithmetic example, 500 ft² with 40 ft² maximum coverage per bag needs ceil(500 / 40) = 13 bags. If the same hypothetical row requires 28 bags per 1,000 ft², density requires ceil(0.5 × 28) = 14. The final order is 14 before a separately selected allowance.

Installed and settled depths remain distinct outputs. Do not lower the bag count merely because a loose-looking layer appears deep enough. Use the selected product’s documented chart requirements.

Existing material condition, access, air sealing, ventilation protection, moisture and cleanup can change the project. Ask installers to quote the same thermal target and scope. The linked manufacturer libraries provide current-document starting points; stale PDF redirects and search snippets are not accepted here as verified product presets. Material selection still needs a suitable project assembly.