25 Checkpoints for Inspecting Insulation Jobs

Wall Areas

1. Cavity Fill. The batts or loose-fill should fill all standard and narrow cavities completely: no gaps top or bottom.

2. Electrical Wiring. Insulation should be split or cut to fit around wiring.

3. Electrical Boxes. Batts should be cut to fit around electrical boxes with a piece placed behind each box.

4. Plumbing. Insulation should be placed between the outside wall and the pipes. If kraft facing is used, it should be in substantial contact with the gypsum board.

5. R-value. The R-value should be marked visibly on the insulation, faced or unfaced. The R-value should meet or exceed the minimum code requirements.

6. Fitting. Batts should friction fit snugly in the cavity. Faced batts can be inset or faced stapled as needed. If inset stapled, batts should not be overly compressed.

7. Vapor Retarder Placement. It should be towards the "warm in winter" living area except in extremely humid areas. (Note: Kraft facing should never be left exposed.)

8. Vapor Retarder Integrity. Taping vapor retarder facings is not standard practice. Small tears and gaps are not expected to cause moisture issues but can be repaired if desired.

9. Vapor Retarder Materials. When required, appropriate vapor retarder materials may include kraft facing, continuous polyethylene sheeting, vapor retarder paints and "smart" vapor retarders. (Note: Polyethylene should only be used in very cold climates.)

10. Bay Window. The outside wall, extended floor, and ceiling should be insulated.

11. Window and Door Areas. Spaces around windows and doors should be filled with insulation or caulked. Do not overstuff.

12. Band Joists. Insulation with a nonflammable facing should be used for band joists.  


Ceilings and Floors

13. Cantilevered Floors. These should be insulated at the floor R-value requirements.

14. Attic Openings. The attic opening should be insulated with insulated covers or a piece of batt insulation at the same R-value as the attic requirements and secured in place.

15. Attic Cards. A completed attic card may be placed near the attic opening when blown insulation is installed.

16. Attic Rulers. When blown insulation is used, it is good practice to install attic rulers, one for every 300 square feet of attic area. The installed thickness of blown insulation should not be less than the minimum settled thickness on the attic card.

17. Eave Baffles. Baffles should be installed on eaves with vents.

18. Knee Walls. Knee walls should be insulated at wall R-value requirements. Insulation should be supported with an appropriately fire-rated backing on the exterior side.



19. Air Infiltration. All insulation requires proper air sealing or the installation of a rated air barrier. All air paths should be sealed using caulk, tape, air barriers or other air sealing measures.

20. Wet-Installed Insulation. Any insulation installed with water should be thoroughly dried before covering with gypsum board. Humid climates may require longer drying times.

21. Combustible Sources. Keep all insulation at least 3 inches away from combustible sources such as chimneys, non-IC fixtures, and heated flue pipes.

22. Unheated Rooms. The walls, ceilings, and floors between living space and unheated areas should be insulated.

23. Shower/Tub Enclosures. Insulation should be installed between tub enclosures and outside walls.

24. Exposed Facings. Unfaced or special faced insulation products, such as FSK-25 insulation, are acceptable for exposed applications. In an exposed application, it is not acceptable to place a flame spread rated facing, such as foil cap sheet, over a non-rated facing, such as kraft paper or standard foil.

25. Wet Insulation - Incidental wetting during installation is not usually a problem. Fiber glass batt insulation wetted with clean water can usually be dried and reused. All saturated loose-fill insulation should be replaced.  

*These checkpoints should be considered a guide and useful information for improving your insulation job.  They do not guarantee compliance with building codes.


Installing Insulation

Building Insulation - Performance Comparison

DOE R-Value Recommendations

Places to add Insulation for $ Savings and comfort

25 Checkpoints for Inspecting Insulation Jobs

Installation Guide - Fiber Glass Loose Fill Insulation

Air Infiltration - Myths and Realities