The insulation used in most homes today comes in a variety of materials and forms. In order to achieve the best possible energy savings and comfort, you will typically see a combination of insulation types installed throughout your home.

Insulation Material Types

Fiberglass Insulation

Fiberglass insulation is perhaps the most commonly used type of insulation found in the home. It is made up of very fine glass fibers created by spinning molten glass Fiberglass insulation typically comes in batt form, roll form, and even loose-fill form. On its own, fiberglass is nonflammable (unless faced with a paper or other flammable material). Fiberglass is not considered an adequate vapor barrier unless it is faced with foil or another vapor-proof material.

Cellulose Insulation

Typically used as a form of loose-fill (blown-in) insulation, cellulose insulation is typically made from recycled newsprint and wood fibers. This material is shredded, ground, and formed into small particles that are fibrous and can be packed tightly into a wide variety of spaces in the home. When installed properly, cellulose insulation restricts airflow, resulting in a high thermal resistance of R 3.6 to R 3.8 per square inch.

Cellulose insulation tends to be safer – no formaldehyde or other chemicals are used as binders and, unlike fiberglass, loose fibers don’t pose any kind of health risk to the installer. In an effort to make the cellulose material fire resistant and insect proof, some insulation manufacturers treat the insulation with latex and other chemicals. Because of this, cellulose insulation that is exposed to persistant moisture can lose their flame-retardant quality over time.

Insulation Form Types

Blown-In Insulation

Blown-in insulation is a popular choice for both open-area (attic insulation) and closed-area (walls and floors) applications. The most common materials used for blown-in insulation projects are fiberglass and cellulose.

While the installation of blown-in insulation does require some extra equipment, the process requires a lot less prep work than installing batts or rolls because you only need to measure the full square footage of the area to be insulated, not individual sections between studs. And because blown-in insulation covers the entire surface of whatever is being insulated, the chance of having accidental air leaks is much less likely than with other types of insulation.

In fact, if you are looking to improve the effectiveness of your existing batt or roll insulation, blown-in insulation can simply be blown on top of whatever is currently installed, adding to the overall R-value and eliminating any existing gaps and leaks.

Batt Insulation

Typically made from fiberglass, batt insulation has a somewhat higher R-value than other insulation forms because of its relatively higher density. Batts can be purchased in several standard dimensions that make it ideal for installing in walls and attic floors between studs. Care must be taken during installation, however, to eliminate any kind of gap or path (around electrical boxes or other in-wall objects) that would allow air penetration or condensation. For that reason, it is common to see batts installed in two layers with sheets position perpendicularly to prevent any type of gap or channel from forming.

Batts come in a wide range of R-values, with fiberglass batts generally pulling the highest numbers. A high-density fiberglass batt for a 2 x 4 wall runs an R-value of about 15, compared to other materials that are considered medium or low density with R-values between R 11 and R 13. If you have walls with 2 x6 construction, the R-value for a high-density fiberglass batt will be around R 21.

Roll Insulation

Roll insulation is a variation on the batt – both are manufactured the same way up until they’re cut to their final size. Rolls come in a variety of widths and lengths, making them ideal for installation into long-running walls, ceilings and floors.

Like batts, rolls are typically made of fiberglass and come in a range of densities and R values.

Spray Foam Insulation

When rolls and batts won’t cover it all, insulation can also be sprayed, injected, poured, or foamed in place. This allows for even the smallest areas to be insulated, and generally provides an R-value of more than twice that of batt insulation per square inch of space. Foam insulation is extremely resistant to both water and air penetration, and ranges from flammable to fireproof depending on the exact material used.

The type of foam used in today’s insulation products is similar to that which is found in cushions, mattresses, and pillows. Due to advances in insulation technology, most foaming agents no longer contain chlorofluorocarbons (CFCs), or hydrochlorofluorocarbons (HCFCs), which have been shown to damage the ozone layer. Today’s foam insulation is generally made from one of the following materials: polyurethane, phenolic, cementitious, or polyisocyanurate.Less commonly used types of foam may include tripolymer, or icynene.

Pipe Insulation

Pipe insulation can be essential for protecting incoming water pipes from freezing and bursting, and can also make your internal plumbing more energy efficient. In fact, taking the time to insulate hot water pipes running through your home can reduce the heat that is lost by as much as 4 degrees, which should allow you to lower your water heater temperature and lighten the load on your heating bills.You’ll also enjoy not having such a long wait for your water to heat up when you turn on the shower or faucet, which will help to conserve water.

The best type of pipe insulation is fiberglass insulation that can be tightly wrapped around the pipes. You can also use pipe sleeves that are made of neoprene foam or polyethylene foam. If using sleeves, you should always choose ones that closely match the diameter of the pipe to ensure a tight fit, thus resulting in the most efficiency.

As a general rule, all accessible pipes within a three foot range of the hot water heater should be insulated. You may also want to insulate the cold water pipes within the same range. If you have a gas water heater, insulation should be installed no closer than six inches from the flue. If the pipes are closer than eight inches to the flue, one inch thick fiberglass pipe wrap is the safest choice.