Why pay to heat escaping air?
Learn basic ways to tighten, insulate and ventilate a home.
Many people learn that their home leaks air and needs insulation after conducting an energy audit.Tightening the home and adding insulation is necessary to stop cold, outside air from coming into the house through cracks and openings, warming, rising and finally escaping through attic cracks and openings. Why pay to heat escaping air that does not contribute to a warm, comfortable home?
To tighten your home, you will need some basic air sealing material. Caulk, a semi-solid substance like toothpaste, is used where different building materials meet. It comes in a tube or as roping. Foam sealant is for larger gaps. It works by expanding to fill space and hardening. Weather-stripping can be made out of metal, foam, rubber, vinyl or felt and goes in gaps between movable parts of doors and windows.
The best strategy is to start at the top of the house where the air is leaking out. Close any gaps between the attic and living space. Then tackle the low spots where cold air gets in – around window and door frames and between the living space and basement. Take special care around plumbing stacks, chimneys and attic doors.
Look for clues of roof leaks or air carrying moisture in the attic. Is the insulation wet or are there signs of mold? Before adding insulation, you need to eliminate the moisture and source of the moisture. Fix the roof or get a new one. Vent bathroom and kitchen fans through the roof not the attic. Paint bathroom and kitchen ceilings with vapor barrier paint. Use a vapor barrier on the attic floor.
Once you ensure moisture-free attic air, you need to plan the ventilation so that dry air circulates freely. Most people need ridge vents and soffit vents; seek expert advice when ventilating an attic – it is crucial.
Insulation keeps heat inside the house during winter and outside the house during summer. It acts as a barrier to heat loss or heat gain. The strength of the barrier is measured by the insulation’s R-value or ability to resist heat. The higher the number the more resistant it is. New attic insulation should be R-49 in Michigan.
Different kinds of insulation are used in different places. Batts, blankets or rolls are used in unfinished, framed-in areas: walls, attic, basement, crawl space ceilings. Buy with a vapor barrier or if unfaced, use a vapor barrier. Do not compress the insulation; the material resists heat because it traps air in its honeycomb-like structure, flattening it defeats the purpose.
Loose fill is made from cellulose, fiberglass or mineral wool. It is blown into finished walls and into open or finished attic space. You can rent a machine at a hardware or big-box store and do the job yourself or have a professional install it.
Rigid board is made of plastic and is used in basement and crawl space walls, around slab foundations and behind exterior siding. Spray insulation is sprayed into walls and roof cavities during construction or in knee-walls in unfinished attics. It provides air sealing, a vapor barrier and insulation all in one material.
Before adding insulation to your home, you should eliminate air leaks, control excess moisture, add ventilation and use a vapor barrier in the attic and crawl spaces. Chose the right insulation for the job and enjoy the comfort of your tightened, insulated and well-ventilated home.
- Iowa State University and Iowa Energy Center: “Home Tightening, Insulation and Ventilation”
- Montana State University Extension:
“Exploring Energy Efficiency and Alternatives: Air Sealing”
“Exploring Energy Efficiency and Alternatives: Attic and Ceiling Insulation”
“Exploring Energy Efficiency and Alternatives: Home Insulation Choices”