The insulation work at our East side home has been completed. This is a very important part of the home building process. There are several options for wall insulation, such as fiberglass batts, blown cellulose, blown fiberglass, foam, etc. Each particular insulation has its own advantages. For this home we selected blown fiberglass…commonly called the blow-in-blanket-system, or BIBS for short.
With BIBS insulation a membrane net is stapled very tightly to the wall framing. Holes are cut into the membrane at each wall stud cavity every 3’ or so. A hose nozzle is poked into the hole and white fiberglass insulation is blown into the wall cavity. This has to be done with the proper amount of pressure….too much and the insulation can become too dense to work well…to little pressure and the insulation will end up settling in the walls over time. Once the insulation is all blown in place, the walls are covered with a heavy polyethylene vapor retarding membrane. This membrane is caulked to the edges of the wall framing and window and door openings. All seams in the polyethylene are taped closed with special red tape.
The rim joist area in this house is 18” high on each floor level. These can be difficult areas to insulate. With smaller joists we often use insulated rim that have foam insulation sandwiched between two layers of structural sheathing. On this house we ran the regular wall sheathing down over the ends of the floor joists. We then had foam insulation applied to the interior surface. This creates an air tight, well insulated surface.
The goal with insulation is to install it properly in such a manner that it stays dry. Wet insulation does not work well at all and can cause major problems with a home. It is also important to install the vapor retarder membranes properly. When this is all done correctly the house ‘breathes’ properly through its mechanical system, not through the walls and ceilings.