How to Install Fiberglass Insulation on Top of Radiant Barrier Insulation

Calculate the amount of radiant barrier and fiberglass insulation needed for the project. For the barrier material, remember to calculate the amount needed to completely in case the wall and studs. Double the amount of barrier you plan to purchase to account for the second layer.

Spread the radiant barrier sheeting over the wall. Spread it over the wall and staple it down over the studs and wall boards. Overlap sheets by 2 inches and staple them together until the entire wall is covered.

Install a second layer of radiant barrier over the first. Start at a different point of the wall so that the seams from the second layer are in a different spot than the first layer.

Place fiberglass insulation between the wall studs, starting at the top of the wall and inserting as you go down. Ensure that the paper backing side faces out, and that the fiberglass is snug against the radiant barrier. Cut the insulation with a utility knife so it fits evenly from top to bottom.

Align the paper side wings so they extend out over the end of the stud and apply staples every 2 inches to secure it. Tape any tears to the paper backing with duct tape to keep the layer sealed.

Work around the room placing fiberglass insulation between the studs until they are all filled and the paper backing is stapled securely to the wall studs.