When it comes to insulation, it's essential to understand the recommended R-value for your climate. In colder climates, an R-value of 49 is suggested, while in warmer climates, an R-value of 30 is recommended. Fiberglass insulation has an R-value of approximately 3 per inch of thickness, while cellulose has an R-value of approximately 4 per inch. However, cellulose does not retain its R-value rating as well as fiberglass.
To ensure optimal air flow and energy efficiency, two layers of insulation should be installed in your attic. The first layer should be placed between the beams and the drywall, acting as a vapor barrier. The second layer should be placed perpendicularly over the beams, extending 90º from the first layer. It is important to note that you should not place a second moisture barrier between the two layers of insulation, as this could trap moisture and cause damage.
It is possible to over-insulate your attic, which can have a negative impact on air circulation and energy efficiency. If you have four feet of insulation stacked all over the attic, this could affect how efficiently the attic can circulate air. This is a big deal and may require hiring an attic insulation removal service to prevent further damage and potential health problems. If you're not sure what to do, you might want to consider doing a professional inspection and replacing the attic insulation.
Before looking at why it's possible to over-insulate, it's worth taking a short detour to learn how attics are supposed to work. A house with a poorly insulated attic will experience more significant temperature fluctuations throughout the day. If you have well-installed attic insulation with a sufficient R-value and are still not satisfied with the results, you may want to consider installing a radiant barrier.
