Part 2 of this series covered how to lay fiberglass insulation. Part 3 is about how to keep that insulation out of the soffit vents by installing baffles.
To completely cover your attic floor with insulation out to the eaves, you need to install rafter vents, also called insulation baffles. Rafter vents keep the soffit vents clear and provide a channel for outside air to move into the attic at the soffits and out through the gable or ridge vent.
Rafter vents go in between the rafters where the ceiling meets the floor. Once they are in place, you can install either batts or blown-in insulation out to the very edge of your attic.
To install the rafter vents, staple them directly to the roof decking. Rafter vents are most commonly 4 feet long and 14.5 or 22.5 inches wide. They are readily available at home centers.