Frequently Asked Questions (FAQ)

Whether you're upgrading your home's current insulation or repairing insulation that has been soiled or damaged by pests like wildlife or rodents, you may have questions about insulation and the insulation installation process. Eastside Insulation is here to help. Below are some questions that we are asked all the time by customers:


What does R-value mean?

The "strength" of insulation is measured by "R-value." R-value measures insulation’s resistance to heat flow. Sometimes it is referred to as “thermal resistance.” The higher the R-value, the greater the insulating power. All materials having the same R-value, regardless of type, thickness, or weight, are equal in insulating power. The R-value of different insulating materials must be based on test methods established by the American Society of Testing and Materials (ASTM). Remember that R-values are determined by material type, thickness, and installed weight per square foot, not by thickness alone. Insulation helps keep your home cool during the summer months and warm during the winter months.


How much will I save by adding insulation to the walls, ceilings and floors of my home?

Making the decision to update or upgrade your insulation is a smart choice. Insulation saves money, increases home comfort, and protects the environment by reducing energy use. According to the U.S. Department of Energy (DOE), the typical U.S. family spends close to $1,500 each year on energy bills. DOE statistics show that, typically, 44% of a homeowner’s utility bill goes for heating and cooling costs. DOE states that homeowners may be able to reduce their energy bills from 10% to 50% by taking certain steps. One of the most important steps is increasing the amount of thermal insulation in their existing homes or purchasing additional insulation when buying new homes.

Unless your home was constructed with special attention to energy efficiency, adding insulation will probably reduce your utility bills. The amount of energy you conserve will depend on several factors: your local climate; the size, shape, and construction of your house; the living habits of your family; the type and efficiency of the heating and cooling systems; and the fuel you use. Energy conserved is money saved, and the annual savings increase when utility rates go up. Insulation upgrades also add to the value of your home.


How much insulation should my house have?

Bob Vila, host of the nationally syndicated TV program that bears his name says, “Insulation is the most efficient energy-saving expenditure.” Vila says homeowners should check attics to determine the amount of insulation already installed. “Most homes built before 1980 have inadequate insulation,” he said, noting that if insulation between the joists of the attic floor comes only to the top of the joist, it probably makes sense to install more insulation.

The U.S. Department of Energy recommends home insulation R-values based on where you live. See R-value recommendations for your climate zone.

Be sure your new home complies with current building code requirements for insulation. These building codes establish minimum levels of insulation for ceilings, walls, floors, and basements for new residential construction.


What are the different types of insulation materials?

There are many different kinds of insulation used in homes. Among these, the most popular are fiberglass, cellulose, foam, rock and slag wool, and reflective insulation.

  • Fiberglass is made from molten sand or recycled glass and other inorganic materials under highly controlled conditions. Fiberglass is produced in batt, blanket, and loose-fill forms.
  • Rock and slag wool are manufactured similarly to fiberglass, but use natural rock and blast furnace slag as its raw material. Typical forms are loose-fill, blanket, or board types.
  • Cellulose is a loose-fill made from paper to which flame retardants are added.
  • Foam insulations are available as rigid boards or foamed-in-place materials that can fill and seal blocks or building cavity spaces. Foams are also used in air sealing to fill gaps, cracks, or openings.
  • Reflective materials are fabricated from aluminum foils with a variety of backings such as polyethylene bubbles and plastic film. Reflective insulations retard the transfer of heat; they can be tested by the same methods as mass insulation and therefore assigned an R-value.
  • A Radiant Barrier is a building construction material consisting of a low emittance (normally 0.1 or less) surface (usually aluminum foil) bounded by an open air space. Radiant barriers are used for the sole purpose of limiting heat transfer by radiation!


What words should I watch out for in a contract or job estimate?

Once you have chosen an insulation contractor, make sure the contract includes the job specification, cost, method of payment, and warranty information provided by the insulation material manufacturer. Make sure that the contract lists the type of insulation to be used and where it will be used. Make sure that each type of insulation is listed by R-value.

Avoid contracts with vague language such as R-values with the terms “plus or minus”; “+ or -“; “average”; or “nominal.”

Beware of any contract or verbal offering that quotes the job in terms of thickness only (e.g. “14 inches of insulation”). Remember, it is the R-value — not the thickness — that tells how well a material insulates. When buying insulation, be sure not to get sidetracked by the thickness of the material.


What must new home sellers tell the new home buyers?

Every new home seller must put specific information about insulation in every home sales contract. See Federal Rule 460.16 for details. Local and state governments may have additional rules and regulations governing consumer contracts. You can read more about the Washington state energy code residential provisions here.



Why hire a professional insulation contractor rather than a home improvement contractor or general contractor?

Professional insulation contractors devote their time to insulation contracting services and focus on your energy conservation and comfort. Proper installation is essential for insulation to perform properly. Knowledge of vapor retarders, air infiltration, ventilation, recessed lighting, and water pipes are just a few of the areas critical to installation techniques. Professional insulation contractors have access to a wide variety of training, are familiar with local codes and regulations, and can offer guidance about the type and amount of insulation to be used.



Can insulation help reduce unwanted sound?

Yes. Insulation is a very efficient and effective way to reduce unwanted sound, and it is commonly used to provide a more comfortable and quieter interior environment. Insulation effectively reduces noise transmission through floors and through interior and exterior walls. A professional insulation contractor can help you select the proper insulation for your needs. One of the most effective materials used is soundproofing foam insulation. Learn more about Eastside's soundproofing foam insulation installation services.


Where can I get more information about insulation?



More Questions? Call us! (425) 482-2121