ShareThisBy DWIGHT BARNETT
Sunday, October 22, 2006
Q: A few years ago my grandparents had these guys come and insulate the attic _ or so they thought. I thought the attic was just fine before the work. But they tore this pink cotton-looking stuff out of the ceiling and did some other stuff and now it gets really hot up there in the summer and cold in the winter. I want to get it back the way it used to be, like the rest of the house. Can you help me?
A: From your description, it appears your grandparents had a walk-in attic space with "pink cotton-looking" insulation in the ceiling of the rooms below the attic space.
Most homes constructed before 1975 had little or no insulation. After heating costs soared following the oil embargo of 1974, many homeowners and builders began to use ceiling and wall insulation to reduce heating and cooling costs.
In pre-1975 homes, the amount of attic insulation might vary from 2 to 6 inches of a fiberglass blanket, rock wool blanket, cellulose blanket or loose fill vermiculite. As far as I know, there were no federal or state regulations governing the size, type or amount to be used prior to 1975.
In your grandparents' home, the "pink" insulation was so ineffective that the heated air from the home passed right through the ceiling, warming the attic space in the winter. Similar air flows would have some cooling effect in the summer, but I imagine the attic space would be quite warm if the roof received direct sunlight.
I don't know why the contractor would have removed the older insulation, unless it was damp or had an exposed vapor barrier attachment. I often find blankets of insulation with the vapor barrier exposed, which usually indicates the insulation is upside down. The vapor barrier must be applied toward the heated side of the home. In an attic the vapor barrier has to be under the insulation and against the ceiling.
Or maybe the contractor insulated the spaces between the rafters of the roof, which is ideal if the attic space is to be used for storage. Here the vapor barrier would be exposed and would need an ignition barrier to prevent a fire.
Read the label when installing insulation and follow all directions. In addition to reworking the insulation, the contractor would have most likely sealed openings to prevent air leaks from the home to the attic and would have increased the ventilation openings to allow the attic air to be exchanged with the outside air at a greater rate.
If you convert the attic space to a living space, you will have to install wall and ceiling coverings to separate the new room from the attic space, then provide ducts for heating/cooling.
Before taking on such a large project, ask the contractor whether the floor system will support the added weight, the electrical wiring is up to code and the furnace fan is capable of supplying cold air to the room.
A typical home furnace fan located in a basement cannot efficiently push cold air to a second-floor or attic room. Heating is not a problem as heated air rises, but cold air tends to stay on the lower levels and attracts heat as it is pushed higher by the fan.
(Dwight Barnett is a certified master inspector with the American Society of Home Inspectors. Write to him with home improvement questions at C. Dwight Barnett, Evansville Courier & Press, P.O. Box 286, Evansville, Ind. 47702.)
