What Is the Best Way to Insulate a New Home?
Choosing the most energy efficient insulation for your new home is one of the best ways to reduce your monthly bills over the home's lifetime. Fiberglass batts are slowly being pushed to the wayside by more efficient home insulation materials such as spray foam and cellulose. While these new home insulation materials may cost more than traditional fiberglass insulation, you can recoup the cost of many of these superior insulation materials in only a few years.
Cellulose insulation can be sprayed into walls, filling all of the cavities better than fiberglass for a home that is warmer in winter and cooler in summer. Cellulose insulation is eco-friendly, since it is made mostly of recycled newspaper and is fireproof thanks to the addition of borax.
Borax also prevents insects from living in cellulose insulation. A good thing about cellulose insulation is that even if your attic is insulated with fiberglass batts, you can always add more R value by spraying in cellulose insulation on top of your existing insulation. Home improvement stores such as Lowes and Home Depot sell cellulose insulation in bales and often allow you to use the blower machine for free with a purchase of several bales. Cellulose insulation can be easily applied to a home's attic by a couple of people in a few hours.
When applying more cellulose insulation to your attic you must be careful not to obstruct the air flow from your soffit or gable vents.
Spray Foam Insulation Advantages
Spray foam insulation has been around for more than a couple of decades but is now quickly becoming a mainstream building material in all types of homes . It is now much more affordable, more fire resistant, and compliant with all building codes. Why is spray foam insulation so much better than any other kind of insulation for a new home?
Open cell spray foam insulation, the most commonly used kind of spray foam insulation, has the advantage providing a relatively high R value per inch, (around 3.8) for the cost per cubic foot. When considering spray foam insulation one must realize that this R value remains constant, unlike fiberglass or cellulose insulation which are both affected by moisture. In addition the added benefit of a vapor barrier and that every tiny crack and void are filled with insulation mean a much higher overall R value.
There are many types of spray foam insulation formulations, from soy based to polyurethane and even cement based. Cementitious spray foam is a type of open cell foam that is completely fireproof, sustainable, and resistant to insects. Open cell foam insulation usually requires a moisture barrier on the outside of the home. It fills all voids and cracks and despite the name "open cell" it prevents air from flowing through cracks into the home.
Closed Cell Spray Foam.
A step above open cell spray foam insulation is closed cell. Closed cell spray foam insulation has a higher R value than open cell insulation but comes with a higher cost per cubic foot. It provides a true moisture and air barrier and even adds strength to the structure. You can buy closed cell spray foam insulation kits such as "Handi Foam" online or order them through the commercial desk at Home Depot or Lowes.
Personal Experience With Spray Foam Insulation
We recently built a 1400 square foot home for a family member that was insulated with spray foam insulation. The home also features a Galvalume metal roof, low E windows and energy efficient fixtures and appliances. The home is all-electric and heated and cooled by a 16 SEER Trane heat pump. Average energy cost thus far is in the $40 to $60 range.
An added benefit is that the home is nearly soundproof, with very little street noise due to the soundproofing qualities of spray foam insulation. A whole house fan cools the home for much of the year. A rooftop photovoltaic or solar panel system will be added in the coming months which will supply all of the home's electrical needs. Moisture is monitored using a humidity meter and the HVAC unit is periodically used to remove excess moisture when needed or on very hot days.
Why Spray Foam is One of The Best New Home Insulation Materials
The traditional methods of insulating a new home have generally involved insulating just above the ceiling and using attic ventilation to remove excess moisture from the home. The problem with this concept is that unfiltered outside air freely moves through the attic, adding moisture to fiberglass or cellulose insulation, thereby reducing its R value. In addition, all of this dirty outside air causes a buildup of dirt in the attic.
Vermin and insects may invade the attic and anything stored in the space is subject to extreme hot and cold. The new way of thinking when using spray foam insulation involves insulating the home all the way to the rafters, thereby making an insulated envelope around the entire home.
The HVAC system and duct work are then inside a controlled environment that is typically only a few degrees in difference between the living space. This allows the HVAC system to perform much more efficiently since there is no buildup of hot or cold air in the ducts. Though this is a hard concept for traditional builders to wrap their heads around, insulating the entire building envelope is the industry standard for foam insulation of all types.
The old concept of "don't build a home too tight" is slowly disappearing. Fresh air can be brought into the home by the HVAC system using a fresh air exchange. Any outside air brought into the the home is regulated, filtered and warmed or cooled in a heat exchanger first.
The end result of insulating a home with spray foam insulation is that utility bills are typically 60% to 70% lower than a traditionally insulated home. Because of this incredible increase in efficiency many cities are looking at eventually banning fiberglass insulation in favor of spray foam to reduce the amount of new power plants being built.
Another Benefit, Spray Foam Insulation Won't Intefere With Cell Phone Reception
An added benefit of spray foam insulation is that it will not cause problems with your cell phone. Many types of insulation, including foil backed fiberglass batts and foil radiant barrier insulation will cause cell phone signal problems. That's because these types of insulation reflect cellular signals away from the inside of your home much the same way they are designed to reflect heat.
If your home already has foil backed or radiant barrier insulation and you have poor cell phone reception, there isn't much you can do about it besides rip it out, or install a "cell phone signal booster" which creates a cell phone "hotspot" in your home. Cell phone signal problems such as dropped calls, are usually not an issue with spray foam insulated homes.
This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.
© 2010 Nolen Hart