Gale Tedhams: Hi! I am Gale Tedhams, I am with Owens Corning and we are just about ready to start insulating this attic using Batt Insulation. Now we are going to start at the far corner, and work ourselves in so that we can have access to the attic stairway, we don't insulate ourselves into a corner. So we will be cutting batts as we go along either to make them in pieces that we can handle or to fit into places, so what you will do is you will measure the piece and then use a straight edge where you can compress the batt and then cut it in a couple of strokes with the utility knife, so that you have a nice clean cut.
In case the cavity isn't completely full, fill the cavity with insulation up to the top of the joist, that way then you can put the next level of batts perpendicular to the joist and that will insulate the joist itself. Another thing that we have to keep in mind is not to cover up the soffit vents that are along the eave of the roof line. Rafter vents like this one are used to maintain that ventilation space form the soffit vent all the way up to the hip or the ridge vent of the roof.
This one is made of Extruded Polystyrene foam and it will not rather deteriorate, so it will maintain its performance through the life of the home and it comes in a size, so that you can use it into between 16 or 24 inch rafter spacing. So what we do is we will cut notches into that first row of batts and fit them around the rafter, so that it fits snug. So that's how you install batt Insulation in an attic. Next we are going to insulate an attic using Loose-Fill Insulation