Get Cozy! Learn the Basics of Insulation for Your Old House

Shannon Lee

If your home was built before the 1940s, chances are there's not much insulation in the walls and ceiling. Because there is nothing charming about the chill of an old house during the harshest winter, adding insulation to your home is probably a good idea.

Adding Insulation to Your Old House: Where to Begin

How do you know where insulation is needed, or even how much? These tips can help:

  • Look at what you have. Remember that warm air rises, so insulation in your attic can help keep more heat in your home during the winter months. A visual inspection makes it easy to tell how much insulation you have in your attic, but the insulation in your walls is more difficult to determine. Look for small patched holes on the exterior of your home; those are telltale signs of blown-in insulation.
  • Determine the best type. Insulation comes in four basic application types: Loose fill, batts, rigid boards, and sprays. Loose fill is typically recommended for old houses, thanks to the ease of application and the ability to reach into places that are tough to insulate with other products. Insulation treated with borates is recommended by the National Park Service.
  • How much do you need? It depends on the area of the country you live in. Insulation with a higher R-value is great for a home in Michigan, but might not be appropriate for a home in southern Florida. Determine your best level of insulation by visiting the Department of Energy website.
  • Start at the top. Always start insulating in the attic, but take care how you do the job. Never block vents in the roof, avoid insulating around old wiring, and pay attention to the position of the insulation vapor barrier in order to prevent moisture problems.
  • Go green. Consider green insulation products, not just for their positive impact on the environment, but for the many advantages they bring to an old house. Products like blown-in cellulose insulation or polyiso are made of sustainable products and often have no asbestos, free formaldehyde, or fiberglass.
  • Be careful. Before you remove old insulation, keep the dangers in mind. Many old insulating products contain asbestos, a known carcinogen. In most cases, leaving that insulation undisturbed is the appropriate solution, but if you must remove it, talk to a professional contractor about the proper way to go about the job.

Insulating an old house doesn't have to be an overwhelming project. A good contractor can give you many options for insulating the structure, and next winter you could be toasty warm while the snow falls.

About the Author

Shannon Dauphin is a freelance writer based near Nashville, Tennessee. Her house was built in 1901, so home repair and renovation have become her hobbies.

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