How to Insulate Around Electrical Wires

Insulation requires dead-air space to maintain the temperature inside your home. However, the dead-air rating that's reported as the "R-Value" of your insulation degrades when the insulation is compressed around plumbing fixtures and electrical wires -- thus squeezing out some of that trapped air. Using the correct installation techniques will ensure dead-air remains inside the insulation and provides your home with the correct R-value.

Things You'll Need

• Tape measure
• Insulation knife

Instructions

1. Use a tape measure to determine the height and width of the stud cavity containing an electrical wire. Press down on a piece of insulation. Pull an insulation knife along the insulation to cut it to length.

2. Push the top of the cut insulation into the top of the stud cavity. Move down along the stud cavity while setting the insulation. Stop two to three feet above an encountered electrical wire.

3. Pull the bottom of the insulation apart to split the insulation vertically, peeling it into separated sections.

4. Slide the back half of the insulation behind the electrical wire. Pull the bottom of the insulation to the bottom of the stud cavity.

5. Lay the top layer of insulation over the electrical wire. Push the insulation into the stud cavity without compressing the insulation. The wire will now be smoothly nestled through the center without compressing the insulation.

Tips & Warnings

• Wear protective clothing to keep insulation from contacting your skin.

References

• Johns Manville: Insulating Around Electrical
• The Family Handyman: How to Install Fiberglass Batt Insulation
• Finehomebuilding: Do's and Don'ts of Installing Fiberglass Insulation