Insulating your attic

Make your home more energy efficient


The insulation of your home, along with the sealing of air leaks and drafts, can help you save up to 20 percent on heating and cooling costs each year.

A poorly insulated attic can decrease your home's energy efficiency, leading to increased utility bills. It can also boost humidity, causing mold growth, rot and animal infestations.

Angie's List asked highly rated insulation companies to weigh in.

  • Do I have enough? When you look at your attic, the insulation should appear voluminous and fluffy. The more the insulation settles over time, the more it loses its effectiveness. If the insulation looks flat and deflated, or it doesn't rise over your floor joists, you might need more. For the best assessment, consider having an energy audit in which infrared technology can detect gaps in insulation.
  • What type of insulation? Most homeowners use either loose insulation made from fiberglass or cellulose, spray foam insulation, or rolls, batts and blankets made from mineral fibers such as fiberglass and rock wool. One advantage of spray foam insulation is it can reach the nooks and crannies of your attic where other types of insulation might be difficult to apply.
  • What is R value? Attic insulation is classified into different R values, which measure thermal resistance. The higher the R value, the better the insulation.
  • Check it often: Since insulation can deteriorate, have it checked periodically to make sure it remains efficient.


Angie's List Tips: Hiring an insulation company

  • Hire help: Adding insulation to your attic yourself is dangerous. You may step through the ceiling or fall through it. A reputable contractor also has the knowledge of what type of insulation should be used for your home based on your climate and region.
  • Ask to see the R-value: You can find the R-value printed on bags or on labels attached to bags of insulation – always ask the contractor to see the bags that will be used.
  • Know your options: Regulation requires contractors to provide consumers with a fact sheet including insulation information on the products they sell. 
  • Check certifications: Ask if the contractor certified by the Insulation Contractors Association of America (ICAA). These contractors have access to training regarding proper installation and are familiar with codes and regulations.
  • What is the cost? Most insulation companies charge by a home's square footage.
  • Read the contract: The contract should include the job specification, cost, warranty information, and method of payment. The contract should also spell out the type of insulation, where it will be used and its R-value. Beware of contracts that list the insulation in terms of thickness - the R-value tells how well a material insulates, not the thickness.
  • Tax credits available: Congress reinstated the energy efficiency home improvement tax credits this year, and eligible homeowners can claim up to $500 in tax credits that had expired at the end of 2011. The credit is eligible for homeowners who have added Energy Star-rated home improvement items, including insulation, to their homes last year or plan to do so this year. Those who have not used any energy tax credits in the past would be eligible for the full $500. Homeowners who have used $300 in credits dating back to 2006, for example, would still be eligible for $200. Homeowners are advised to contact their accountant to see what qualifies as energy efficient and whether they are eligible for the credit.