There are times when more than one layer of insulation will be used. An example of this is in an attic. If the existing attic insulation is an R-19, you may choose to add another layer of R-19. Two layers of R-19 at 6¼ ” thick will achieve a total R-value of 38.
ABOUT INSULATION
The thermal barrier of a home should consist of a continuous layer of insulation on all sides—including the lowest floor, the exterior walls, and the ceiling or roof. Doubling the thickness of insulation will double the insulation's R-value, cutting heat loss in half.
You can double up the insulation. If your air gap is already filled (or mostly filled) adding a second layer will not provide much improvment. If the space is completely filled, adding a second layer will actually reduce the insulation value slightly.
When you stack new insulation on top of existing attic insulation, the existing insulation is compressed a small amount. This will slightly decrease the R-value of the existing insulation. This effect is most important if the new insulation is more dense than the old insulation.
When calculating the R-value of a multilayered installation, add the R-values of the individual layers. Installing more insulation in your home increases the R-value and the resistance to heat flow. In general, increased insulation thickness will proportionally increase the R-value.
There are times when more than one layer of insulation will be used. An example of this is in an attic. If the existing attic insulation is an R-19, you may choose to add another layer of R-19. Two layers of R-19 at 6¼ ” thick will achieve a total R-value of 38.
To calculate the total R-value for the area, simply add the individual ratings for each type of insulation. See How to Install Insulation for do-it-yourself instruction.
Yes, by enhancing the energy efficiency of a building, double insulation reduces the consumption of energy resources and thus contributes to sustainable construction. It can be an integral part of green building practices.
While both types provide insulation, R30 is the better option for maximizing energy savings in areas where heat loss or gain is a major concern. For example, R19 may suffice for interior walls, but R30 is more appropriate for exterior-facing attics or floors.
In many cases you can add new insulation on top of old insulation, unless the old insulation is wet, mouldy, or vermiculite. If the old insulation is dry but appears to have previously been wet, you should look for the cause and repair the problem.
As a general guideline, it's advisable to install double layers of thermal insulation throughout your house.
Because its structure is more complex than single-layer insulation, the cost is relatively high. Additionally, in some cases, double-insulated cables may fail due to spalling between the inner and outer insulation layers.
R19 Insulation offers superior thermal insulation compared to R13. With a typical thickness of 6.25 inches, R19 fiberglass is designed for use in 2x6 wall cavities, making them suitable for colder climates where higher thermal resistance is necessary.
Spray foam will get you the R19 value you need within 4 inches, or they also sell foam boards in home depot - you can use 1 r13 board + 1 R5 board to get to the required R-value. Or, you can effective add 2x2s onto the existing 2x4s and make them 2x6s and use batt insulation.
R15 insulation offers slightly better thermal insulative properties than R13. Some of its formats are a fraction of an inch thicker than R13, making it more effective at helping with energy efficiency. However, the difference is minimal. R15 is slightly thicker than R13 for spray foam and blown-in cellulose.
This is because the second layer of insulation prevents any possible contact between the live parts and the casing. Therefore, even if the appliance is handled or touched when a fault has occurred, the user is still protected from electric shock.
If you double the thickness of your insulation, you're essentially giving its R-value a twin sibling. Double trouble, double warmth!
Thermablok® Aerogel is a revolutionary advancement in thermal technology offering the thinnest insulation available to prevent thermal and cold bridging. Classed as a Super Insulation, Aerogel has the highest insulation value of any known material with the lowest thermal conductivity value of any solid (0.015W/mK).
Achieving Greater R-Values in Exterior Walls
As with attics or anywhere else in your home, adding more layers of insulation to your exterior walls is key to having a higher R-value and better thermal performance.
The R-value of double bubble insulation is typically R-3.5 to R-4, depending on the thickness of the insulation. The ICC International Building Code allows you to add additional R-values with trapped air space between the reflective surface of the bubble and the outer wall.
Unless your home was specially constructed for energy efficiency, you can probably reduce your energy bills by adding more insulation. Many older homes have less insulation than homes built today, but even adding insulation to a newer home can pay for itself within a few years.
It is possible to over-insulate your house so much that it can't breathe. The whole point of home insulation is to tightly seal your home's interior. But if it becomes too tightly sealed with too many layers of insulation, moisture can get trapped inside those layers. That's when mold starts to grow.
R-values are additive for layers of materials, and the higher the R-value the better the performance.
Barricade® R-Wrap® house wrap provides a high level of air and moisture control and prevents water accumulation in the wall system. Both features help protect the R-value of the insulation and help ensure an energy-efficient structure.