Q:

Is it better to staple paper-faced insulation to the face or to the side of the studs? Is this topic addressed in the building code?

Roe Osborn, Woodbury, CT

A:

Gene Leger, a home-energy consultant and former building official in Nashua, New Hampshire, replies: When I was a code-enforcement officer in Nashua, I banned side-stapling of paper-faced insulation to studs and joists for two reasons: fire safety and energy-efficiency. Section 320 of the 2000 International Residential Code (IRC) addresses the fire rating of insulating materials.

Side-stapling creates air channels next to the studs and reduces direct contact between the facing and the back side of the drywall, which creates more airspaces. Coupled with holes in the framing for wires, these channels and airspaces are like raceways for fire to spread through a house. The potential for flame spread is reduced greatly when the insulation’s facing is in direct contact with the drywall.

There’s also an energy penalty because fibrous insulation is dependent on trapped air. Side-stapling not only creates the aforementioned air channels and airspaces but also compresses the insulation. Compressing the insulation decreases the amount of trapped air the insulation can hold and so reduces R-value. Air circulating within the wall cavity also decreases R-value.

Fine Homebuilding Recommended Products

Fine Homebuilding receives a commission for items purchased through links on this site, including Amazon Associates and other affiliate advertising programs.

Great Stuff Foam Cleaner

It’s important to clean and maintain a professional foam-dispensing gun, and this product fits the bill. It has a spray applicator for general cleaning, plus it screws onto the dispensing gun so you can clean the inside.

Buy at Amazon

Caulking Gun

It's important for any insulator to have a good caulking gun for air sealing or adhesives, and this one features a revolving frame that makes orienting the tip a breeze.

Buy at Amazon

Nitrile Work Gloves

Do yourself a favor and protect your hands while you work. These lightweight, breathable work gloves will keep your hands safe while cutting and fitting.

Buy at Amazon