How to inspect residential insulation jobs

The North American Insulation Manufacturers Association's 25-point checklist

Building energy codes ensure HVAC contractors are keeping to energy efficieny standards during installations. But in reality, standards are just that: standards. If you want a competitive edge as a contractor, you'll need to build better and beyond the bare minimum.

For this reason the North American Insulation Manufacturers Association (NAIMA) developed "25 Checkpoints for Inspecting Insulation Jobs" to assist contractors in elevating their insulation installations. From top to bottom, here are NAIMA's inspection tips for a healthier home:

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.

General

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.

The 25 checkpoints from the North American Insulation Manufacturers Association are intended to provide useful guidance on how to improve the quality of the installation of insulation products. Use of this guide does not ensure or guarantee compliance with building codes, acceptance by building inspectors, or compliance with any other type of governmental or building requirements. Use of these guidelines does not guarantee you any specific level of energy savings or dollar savings. Use of this guidance does not guarantee that mistakes have not been made in the installation process. NAIMA encourages consultation with individual manufacturer's guidance on proper installation of their specific products.

For more information on insulation standards and techniques, visit insulationinstitute.org/.

Looking for a reprint of this article?
From high-res PDFs to custom plaques, order your copy today!

Emell Derra Adolphus has more than a decade of writing and journalism experience. He is senior editor of ENR’s Top Lists and Survey Rankings at ENR magazine and frequently contributes stories on technology, climate resiliency, diversity, equity and inclusion.