The answer is yes! Past a certain point, insulation in a vented attic will do more harm than good. In most of the United States, achieving an R-Value of 38 is more than sufficient. In the temperate Southern California region, an R-Value of 30 tends to be ideal.
R-Value is a measure of insulation's ability to resist heat flow. The higher the R-Value, the better the thermal performance of the insulation. The recommended level for most attics is to insulate to R-38 or about 10 to 14 inches, depending on insulation type.
The truth is, your attic plays a major role in your home's overall energy performance and can significantly impact how much it costs to keep your living space comfortable. If your attic is too cold in the winter, too hot in the summer, or both, it's time for some necessary home energy improvements.
Too much of anything is bad, including too much insulation in an attic. Over insulating your house and tightly sealing it too much creates a vapor barrier and forces moisture to settle on fixtures inside your home (hello, water damage!).
Common Lifespans of Different Attic Insulation
Fiberglass Insulation--The actual lifespan of this commonly used attic insulation is from 80-100 years. However, due to its construction with natural materials, eventually the product will lose effectiveness.
As long as you ventilate your property properly, you can have as much insulation as you like within reason. The trick with loft insulation is to balance the amount of insulation you have with the amount of ventilation necessary to prevent damp. As long as you get that balance right, you should be fine.
It may reduce the efficiency by as much as 30 to 50%. About the insulation touching the roof. If the insulation is installed properly, there should be a 2" air space above the insulation to the sheathing. In all practical purposes, this is should be easy to do if the rafters are 10" deep and the insulation is only 8".
Conclusion. Attic insulation can last 80 to 100 years, though it loses its energy efficiency benefits with time. Certified attic specialists' professional advice is to upgrade it every 15 years to ensure that it is still performing the job.
Hot air rises, making much of the heat we lose in our homes escape through the attic. An estimated 25% of all heat loss occurs through the attic or roof of a home.
Thanks to the radiant heat affect, attic temperatures on a 100-degree day can reach 170 degrees or more.
Note excessive heat – if it's 90 degrees outside, the attic temperature shouldn't be more than 110 degrees. More often than not, attic temperatures will be in excess of 125 degrees on a 90 degree day. This will overwork your air conditioning equipment, run up your utility bill and shorten the life of your roof.
The ideal attic temperature should be no less than 60 degrees in the winter and no more than 10 to 20 degrees above the outdoor temperature in the summer.
Here, where temps get pretty hot for much of the year, attics should have from R30 to R60 (average is R38). Those living up north want anything from R49 to R60. This helps insulate against the extreme cold weather. The more insulation you use, the better insulated your home will be.
Even an incremental improvement to your insulation can make a huge difference. Getting your attic brought up-to-date in terms of insulation can significantly cut your winter heating and summer cooling costs.
Proper attic insulation can help keep your home cool in the summer and warm in the winter and minimize drafts and noise pollution. Attic insulation lifespan typically lasts about 10-15 years, but its lifespan can be affected by several factors, including your home's climate, ventilation, and pests.
Moisture accumulation: If attic insulation is not installed correctly, moisture can become trapped in the insulation. This can lead to mold and mildew growth which can cause health problems and decrease the insulation's effectiveness.
Never place insulation close to water heaters, oil burners or anything hot. The backing is especially flammable and will be a major fire hazard for your home.
So, it's always recommended to leave an air gap when installing insulation, whether it's in your walls, roof, or floors.
If you're concerned about having a positive impact on the environment, fiberglass batt is probably the best insulation option for your attic. That's because it's made of recycled sand and glass. Its composition also makes it light-weight and flame-resistant.
If insulation is installed too thickly or packed too tightly into the loft, it can block air flow and prevent moisture from escaping. This can lead to condensation and dampness, particularly in areas where moisture tends to accumulate, such as bathrooms, kitchens, and laundry rooms.
Don't squash the insulation as this can reduce its thermal performance by over 50%.
Many of us know what causes mould; when moisture is trapped in the rooms of you home. Sometimes, there is insufficient insulation in the walls, so mould grows. However, not many people realise that additional insulation isn't always the answer. In fact, too much insulation can be the secret cause of mould.