The U.S. Department of Energy recommends attic insulation levels of R-49 to R-60 for most homes in colder climates, and R-30 to R-49 for homes in warmer climates.
For example, homeowners in the southern United States can begin insulating their attic using materials that have R-values in the R30 to R60 range and R13 to R19 insulation ratings for the floors. Attic insulation should be R49-R60, while floor insulation should be R25-R30 for those in the north of the United States.
Yes, you can use R19 insulation in an attic, but whether it's suitable depends on a few factors: Climate Zone: R19 insulation is typically appropriate for attics in moderate climates. In colder climates, higher R-values (like R30 or R38) may be recommended to effectively prevent heat loss.
You will want to bring up your attic up to R-38:
If your attic has 5-6″ of existing insulation, you'll want to install an R-19 to achieve a total of R-38.
The optimal R-value for most homes is 30, but you can go as high as 38 if you live in a tropical climate. Anything higher than 38 indicates an over-insulated space.
Mold and Mildew Growth
Having too much insulation in your attic can allow for the accumulation of moisture. This leads to mold and mildew growth, which can be extremely bad for your health.
The thinnest insulation material currently available on the market is the 10mm Aerogel blanket. Its manufacturing technology is highly interesting, and its appearance resembles frozen smoke. For some, aerogel is synonymous with time frozen and suspended in space.
The recommended level for most attics is to insulate to R-38 or about 10 to 14 inches, depending on insulation type.
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.
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. So adding an R-19 batt to an existing R-19 batt will give you a total insulation value of R-38.
Heat naturally rises, and without proper insulation, it escapes through your attic, forcing your HVAC system to work harder. 💰 Upgrading insulation can reduce energy costs by up to 30%! ✅ Better insulation = less heat loss in winter and less heat gain in summer.
The most common application of R19 Insulation is in a vertical wall framed by 2×6 studs. As mentioned above this is a common code requirement in some parts of the United States. R19 Insulation can also be used in other areas around the home, including floors and crawl spaces.
The dip from R10 to R4 seems odd, as one would expect more R as you travel further north through the zones. Thicker is not better! Doubling the amount of insulation will double the R-Value, but so what? Doubling the insulation from R-19 to R-38 does NOT cut the heat loss in half (50%) it cuts it by around 3%!
Typically, you use unfaced insulation when you plan to add more insulation to your attic or between the walls and floors of your living spaces at home.
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.
Attic insulation costs anywhere from $1,680 to $3,125, depending on the size of your attic and the material used. On average, most homeowners shell out around $2,380. These costs include the insulation materials and installation by a professional.
As mentioned above, you can always increase your R-Value simply apply an extra layer of insulation over your initial layer.
For regions with milder temperatures, R-30 insulation often meets energy efficiency standards. It is an economical choice for managing heat gain, balancing efficiency without over-insulating, and is suitable for attics, floors, and other areas where extreme thermal resistance isn't necessary.
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.
The U.S. Department of Energy recommends attic insulation levels of R-49 to R-60 for most homes in colder climates, and R-30 to R-49 for homes in warmer climates.
Overall, the second layer of insulation plays a crucial role in improving insulation performance, reducing heat loss, and maintaining a comfortable and energy-efficient living space.
The bottom line is the old insulation needs to be removed because it hinders the airflow into the attic, it can promote mold growth, and it is dirty.
The best kind of rigid foam insulation is polyisocyanurate, also known as polyiso. It has the highest R-rating of any rigid foam insulation and comes with a reflective foil on both sides, allowing it to act as a radiant barrier as well.
It's essential to wear protective clothing and a mask when installing fibreglass insulation to prevent any health risks. Overall, fibreglass insulation is the cheapest and most effective insulation option available, making it a popular choice for homeowners and builders alike.
High R-value: Because foam board insulation has a greater R-value than standard fiberglass/batt insulation, it is more effective at insulating and decreasing heat loss.