TryBuildCalc

Blown-In Insulation Verification Checklist

Essential Checklist+

Complete these critical checks before approving the work or proceeding to the next construction stage.

✓15 Inspection Points
✓5 Verification Categories
✓Measurement & Planning+
  • Area (length x width) for every attic/ceiling plane and floor plane was measured on site, not taken from a floor plan alone.
  • Where insulation already exists, its current depth was measured at several points (not just one spot) and the lowest representative depth was used for the top-up calculation.
  • Dimensions were entered in consistent units — all feet or all meters, not mixed.
✓Product Selection+
  • Target R-value meets or exceeds the local energy code minimum for the climate zone and application (attic/ceiling or floor), not just a generic default.
  • Material choice (fiberglass or cellulose) matches local code/fire-rating requirements and supplier availability.
  • For a floor cavity, a dense-pack-rated material and installation method is being used — not open-blow fiberglass, which the manufacturer does not recommend for closed-cavity application.
  • The specific product's own printed FTC coverage chart (on the bag) was checked and compared against this calculator's estimate before finalizing quantity.
✓Quantity & Purchasing+
  • Wastage allowance (typically 5-15%) was applied on top of the real weight-based total, not used to replace it.
  • The final bag count including wastage — not the raw bag count — was used for purchase.
✓Installation+
  • Insulation is blown to at least the manufacturer's minimum settled thickness for the target R-value across the ENTIRE area, not just the easiest-to-reach sections.
  • Depth markers/rulers are placed across the attic before blowing so installed depth can be checked and compared against the target as work proceeds.
  • Baffles are installed at the eaves before blowing attic insulation so soffit vents stay clear — blocking them traps heat and moisture.
  • Insulation is kept clear of recessed lighting and other heat-producing fixtures unless they're rated IC (insulation contact), per the fixture's own clearance requirement.
✓Safety & Final Check+
  • Skin, eye, and respiratory protection (long sleeves, gloves, eye protection, a dust mask or respirator) was used when handling and blowing insulation.
  • Installed depth was spot-checked against the depth markers at multiple points across the area before considering the job complete.
Full QC Checklist+

Verify measurement, material selection, quantity, installation, and safety before closing up an attic or floor cavity.

✓25 Inspection Points
✓5 Verification Categories
✓Measurement & Planning+
  • Area (length x width) for every attic/ceiling plane and floor plane was measured on site, not taken from a floor plan alone.
  • Obstructions that reduce the real blow-able area (chimneys, large ductwork, skylights wells, structural elements) were accounted for in the entered area.
  • Where insulation already exists, its current depth was measured at several points (not just one spot) and the lowest representative depth was used for the top-up calculation.
  • Dimensions were entered in consistent units — all feet or all meters, not mixed.
  • Separate area rows were used for sections with genuinely different material, target R-value, or application (attic vs. floor) rather than averaging them into one row.
✓Product Selection+
  • Target R-value meets or exceeds the local energy code minimum for the climate zone and application (attic/ceiling or floor), not just a generic default.
  • Material choice (fiberglass or cellulose) matches local code/fire-rating requirements and supplier availability.
  • For a floor cavity, a dense-pack-rated material and installation method is being used — not open-blow fiberglass, which the manufacturer does not recommend for closed-cavity application.
  • The specific product's own printed FTC coverage chart (on the bag) was checked and compared against this calculator's estimate before finalizing quantity.
  • A compatible blowing machine (rented or supplied with purchase) was confirmed available for the chosen material before the installation date.
  • Baffles for soffit/ridge vent clearance are on hand before blowing attic insulation, if not already installed.
✓Quantity & Purchasing+
  • Wastage allowance (typically 5-15%) was applied on top of the real weight-based total, not used to replace it.
  • The final bag count including wastage — not the raw bag count — was used for purchase.
  • Where multiple materials are used (e.g. attic and floor use different products), each material's own bag count was purchased separately, not a single combined total.
  • Product was ordered from the same production batch/lot where visual or performance consistency matters.
✓Installation+
  • Insulation is blown to at least the manufacturer's minimum settled thickness for the target R-value across the ENTIRE area, not just the easiest-to-reach sections.
  • Depth markers/rulers are placed across the attic before blowing so installed depth can be checked and compared against the target as work proceeds.
  • Baffles are installed at the eaves before blowing attic insulation so soffit vents stay clear — blocking them traps heat and moisture.
  • Insulation is kept clear of recessed lighting and other heat-producing fixtures unless they're rated IC (insulation contact), per the fixture's own clearance requirement.
  • Combustion appliance flues, chimneys, and electrical junction boxes retain their required clearance from loose-fill insulation per the manufacturer and local code.
✓Safety & Final Check+
  • Skin, eye, and respiratory protection (long sleeves, gloves, eye protection, a dust mask or respirator) was used when handling and blowing insulation.
  • Adequate ventilation and lighting were maintained in the attic or floor cavity work area throughout installation.
  • A second person was stationed at the blowing machine (hopper-feeding) while the installer worked in the attic/floor cavity, for both safety and installation quality.
  • Installed depth was spot-checked against the depth markers at multiple points across the area before considering the job complete.
  • No insulation was left blocking attic access, electrical panels, or other areas that must remain accessible.
Inspection Notes+
Use the latest approved drawings, specifications, and site measurements.
Complete all critical checks before proceeding to the next work stage.
Record deviations and confirm rectification where required.

Related Calculators & Guides

Blown-In Insulation CalculatorOpen the related calculator and verify the current project inputs.

FAQ

Use it after collecting the project inputs and again before approving or closing the relevant work stage.
No. It supports verification but does not replace approved drawings, specifications, codes, manufacturer requirements, or professional inspection.