How to Install Styrofoam Over Fiberglass Insulation

Insulating a house can be done by installing a combination of fiberglass as well as Styrofoam insulation. Normally, the fiberglass insulation is used between the studs of a house's exterior walls and is installed from the inside. The Styrofoam insulation is usually installed and attached to the exterior walls of a house. The combination of these two types of insulation can result in the Styrofoam insulation being installed over the fiberglass insulation. The installation can be done by following a few steps to attach the Styrofoam.

Difficulty: Moderately Easy

Instructions

Things You'll Need:

• Tape measure
• Utility knife
• Hacksaw
• Pencil
• Hammer
• Nails

1. Use a tape measure to find the dimensions of the area that needs to be covered with the Styrofoam insulation. Measure the height from top to bottom and the width form side to side.

2. Purchase sheets of Styrofoam insulation from a home improvement store such as Lowes or Home Depot.

3. Use the measurements taken of the total area to determine how many sheets to purchase.

4. Install single sheets first as these will not need to be cut to fit. Place a sheet directly over the fiberglass insulation and attach it to the wall.

5. Use a hammer and nails to secure the sheet of insulation to the studs in the wall.

6. Measure areas that are going to need a specific size of insulation cut. Mark the sheet of insulation with a pencil where it will need to be cut.

7. Use a utility knife or hacksaw to cut the sheet of insulation to the correct size and attach it over the fiberglass insulation on the wall.

Tips & Warnings

• Styrofoam insulation can be used as additional insulation in an attic. Use saw horses to make cutting the insulation easier.
• Keep the Styrofoam away from high heat sources, such as portable heaters, as it may be combustible. Styrofoam can be easily ingested by household pets and block their digestive tracts