Re-insulating Existing Homes
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...in Arizona, we know there are hundreds of thousands of homes that have missing or poorly installed attic insulation. |
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At Arizona Insulation Guys we refer to the process of re-insulating an existing home’s attic as retrofit insulation work. We re-insulate attics in older homes that were not insulated to today’s standards and newer homes that were not insulated correctly during construction.
Based on our experience, testing and inspecting homes in Arizona, we know there are hundreds of thousands of homes that have missing or poorly installed attic insulation. During the 80's and 90's mediocre insulation work was the rule. Prior to the 80's, builders simply didn't install enough insulation in attics to get the job done right.
We routinely see huge opportunities to improve the efficiency and comfort of existing homes. People who have five inches of insulation or less can definitely benefit from having more insulation blown into their attics. The feed-back that we have received from our retrofit customers has been outstanding. They feel much more comfortable and they are saving money - "what a concept!"
We tell consumers that if done correctly, retrofit insulation pays twice. First it helps reduce your utility bills. Secondly, when you sell your home you eliminate a price negotiating point from a buyer's home inspector because of inadequate insulation.
Why do we need to re-insulate attics?
We need to re-insulate existing attics for one of two reasons. The first is that the attics were done thirty or forty years ago when the standards were too low. The second reason is that the attic wasn't blown correctly when the house was built. The latter is much more common than you would guess.
Cheating and flagrantly sloppy work were quite common in the insulation industry up until recently. I've inspected over one hundreds of homes the last fifteen years and at least ninety-five percent had significant problems.
For a period of several decades the insulation industry had a gigantic quality control problem. No one was policing blown attic insulation. As a result, I rarely inspected attics with blown insulation where the specified R-value was achieved. Often the attics were missing 20% to as much as 50% of the blown insulation.
Arizona Insulation Guys is not the only business or organization that is acutely aware of these problems. According to the Insulation Contractors Association of America’s, A Plan to Stop Fluffing and Cheating of Loose-fill Insulation in Attics, whatever one calls it, it is fraud. Cheating is prevalent throughout the United States.
The consequences of missing insulation are huge. To drive home the impact of missing insulation take an existing or brand new home that has an advertised R-38. If you have one hundred square feet of insulation missing (5%), the R-value drops to 18.9, which represents a 52% drop for the entire house attic.
The consequences of sloppy or fraudulent work are really obvious you have high energy bills and your home is uncomfortable.
How do I know if I have an insulation problem?
There are a variety of ways to determine if your home needs more insulation. The most direct way is to go up into the attic and inspect it. We've provided enough information to help you make the necessary assessment of your home's insulation. Other tell-tale signs of missing insulation are high utility bills, uncomfortable rooms, and an air conditioner or furnace that won't stop running.
The biggest mistake most consumers make is that they assume their attic insulation is correct. We see brand new homes that are substantially short on blown insulation. We also see older homes built prior to the energy crisis in the mid-seventies that never had an adequate amount of insulation installed in the first place. These older homes have an R-11 batt installed in the attic or three to six inches of blown insulation, which by today’s standards is not adequate to ensure efficiency and comfort. On these older homes additional insulation is a great value and its fairly easy and affordable to install in most cases.
Older homes often have asphalt shingles. These attics run considerably hotter than homes with tile. The asphalt shingle absorbs heat and this heat is transferred into the attic via conduction. Roofing tiles have a curved profile and thus are back-vented. Since temperature difference drives heat gain, homes with asphalt shingles see a hotter and longer summer.
Most new homes have attics that have a "specified" R-30 or R-38. R stands for resistance to heat flow. If your attic has four inches of blown insulation, it would be considered an R-9 to an R-12 depending on the material. In new homes today we'll blow a minimum of 9" of cellulose (R-30), which would settle to 8". For blown fiberglass, we would blow 12" for R-30.
If you are spending more than $100 a month for cooling in the summer and your house is under 2400 square feet you've got problems. Your utility bill is high because you have one of the following conditions: missing insulation, leaky ductwork or poor solar control.
The best way to determine if you have enough insulation is go up and inspect it. We've provided a chart below to help you make the evaluation of your material and R-value. When inspecting it in the attic the closer you get to the eves and the farther from the attic access the more likely you'll find a problem.
If you are unable to get into your attic, call us Arizona Insulation Guys to perform a physical inspection .
The problems are not limited to blown insulation. We often see vertical walls between the house and the attic uninsulated. There are a variety of other areas like chases and misaligned batts that also need to be dealt with. This is why we believe an inspection of the job prior to insulating is critical.
R-value table
Type |
R-11 |
R-19 |
R-30 |
R-38 |
Color |
Blown Cellulose |
3" |
5" |
8" |
10" |
Grey or cardboard colored |
Blown Fiberglass |
4.4" |
7.6" |
12" |
15" |
Pink, white, or yellow |
Fiberglass Batts |
3.5" |
6" |
10" |
12" |
Pink, white, or yellow |
The potential for savings is different for every house. The bigger the problems the greater the opportunity to help consumers reduce their energy bills. If your house is marginal and may not benefit from additional insulation, this is what we'll tell you.
What type of Insulation
You'll find three commonly used types of insulation in attics: blown cellulose, blown fiberglass, and fiberglass batts. All these types of insulation are fine, if installed at the right levels and densities. The key thing to keep in mind is that any insulation material can be undermined by poor installation.
You can identify blown cellulose because it is a gray. It is a cellulose fiber derived from recycled newsprint and is treated with a fire retardant. This material has an R-value of 3.7 per inch. It will settle when installed in attics and if installed correctly this settling is factored into the installation. For instance we blow 9" of cellulose, which we know will settle to 8".
Blown fiberglass comes in three common colors: white, pink or yellow depending on the manufacturer. Blown fiberglass is made from silica or sand. This material has an R-value of 2.5 - 3.0 per inch when installed at the correct density. The problem with blown fiberglass is that it can be fluffed; i.e. whipping the blown fiberglass up with air, which compromises density and thus R-value. We do not recommend blowning glass its simply not as good as cellulose.
There are other types of obscure insulation that we have not described in this guide. We have seen cardboard colored cellulose in older homes in Central Phoenix. We also have seen plenty of green and black rock wool insulation. Simply assume the R-values of these materials vary between R-2.0 and R-3.0 per inch. In extremely old homes we've come across wood chips and batts made out of cellulose.