How much insulation should you have in your attic?

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.

Can you put too much insulation in an attic?

It's possible to over-insulate an attic as too much will cause moisture buildup and eventually result in mold. Eventually, adding more insulation leads to diminishing returns in trapping heat as well.

Is 6 inches of attic insulation enough?

Most joists are six to seven inches tall, and if they are completely filled with material, they are insulated at R-21. However, the DOE recommends that attics in Southern homes be insulated with 13 to 14 inches, or R-38, of insulation at minimum.

Do I have enough insulation in my attic?

Looking across your attic, if the insulation is level with or below the attic floor joists, you probably need to add more insulation. Assumes R-3/inch. If you cannot see any of the floor joists because the insulation is well above them, you probably have enough, and adding more insulation may not be cost-effective.

What R-Value do I need for attic?

Depending on where you live and the part of your home you're insulating (walls, crawlspace, attic, etc.), you'll need a different R-Value. Typical recommendations for exterior walls are R-13 to R-23, while R-30, R-38 and R-49 are common for ceilings and attic spaces.

Things To Know Before Insulating Your Attic | Improve Comfort

Is R-38 insulation Good for attic?

So, for your attic insulation, we have a minimum standard of R-38, and a recommended standard of R-49. R-Value is explained as thus: “the resistance, or strength of a material to slowing down the flow (movement) of heat”. Generally speaking, cellulose attic insulation doesn't care which way the heat is moving.

Is R30 insulation good for attic?

The average recommended level is 14 inches of R49. In Zone 2, the average minimum requirement for attic insulation is 9 inches of R30 fill. The average recommended level is 17 inches of R60. In Zone 3, the average minimum requirement for attic insulation is 9 inches of R30 fill.

Should I remove old attic insulation before adding new?

Unless it's water damaged or rodent-infested, you do not need to remove your attic insulation. Remember, if you are concerned about dust and air quality, you need to have your attic air sealed to separate the attic from the house before you add more insulation, otherwise you'll just make the dust problem worse.

Can you put new attic insulation over old?

Yes! You can absolutely new insulation over old insulation… as long as it isn't wet. Energy Star advises as follows: “If it… appears that the insulation [is wet or] has previously been wet, you should look for the cause and repair the problem to prevent a reoccurrence.

What should insulation look like in attic?

Cellulose Insulation

In general, it looks like shredded gray paper. Cellulose insulation is a perfectly safe type of insulation that is commonly blown into attics.

How do you tell if attic is well insulated?

How often should attic insulation be replaced?

However, due to its construction with natural materials, eventually the product will lose effectiveness. Fiberglass insulation typically needs to be replaced 15-20 years into it's life, as it can easily become dirty, wet, moldy, and ineffective if there's a roof leak or water damage of any kind.

Can a house have too much insulation?

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.

Is R60 attic insulation worth it?

Recommended R-Value Varies by State

You need exactly as much as the area you live in determines. 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.

Should you insulate the attic ceiling?

Proper attic insulation can also keep your roof in better condition by helping to prevent ice dams and condensation. Your building codes may require you to have a certain quality of insulation. However, installing even better insulation is to your advantage and your roof's advantage.

Does doubling insulation Double R-value?

Doubling the thickness of insulation will double the insulation's R-value, cutting heat loss in half. Each time the insulation layer is doubled in thickness, this rule applies.

Is replacing insulation worth it?

While insulation has a long lifespan, it does not last forever. If you own an older home, you may find that replacing the insulation saves you a significant chunk of money on your heating and cooling bills.

What is the best way to insulate your attic?

One of the best ways to banish cold from your living space is to insulate the attic. Since heat rises, the attic is the logical place to install insulation. You can insulate your attic either by blowing in loose-fill cellulose insulation or by laying fiberglass batts between the ceiling joists.

How often does insulation need to be replaced?

Unless damaged, it can last 80 to 100 years in most houses before it needs to be replaced. However, insulation can start falling from fiberglass batts after 15 to 20 years, so if your insulation was installed in batts well over a decade ago, it might be time for an inspection or a home energy audit.

How long does blown in insulation last?

How Long Does Blown in Attic Insulation Last? Regardless of what kind of insulation you choose, blown insulation is a permanent solution. Cellulose insulation lasts 20-30 years because it is made from recycled natural materials, whereas fiberglass materials will last much longer because it does not degrade.

Can old insulation make you sick?

Attic insulation is an essential part of our homes, but dirty, old, poorly installed insulation can make us sick. While insulation may not be something you usually spend your time worrying about on a day-to-day basis, it's a worthwhile question to ask.

What is the R-value of 4 inches of insulation?

For areas with 3-4 inches of existing insulation, you will need an R-value of 38-49. For insulating flooring, you will need an R-value of 25-30.

Which is better R19 or R30 insulation?

The bigger the R value, the better the insulation is at slowing down the heat transfer. So R19 is better insulation than R13, and R30 is better than R19. The larger the R value, the better the insulation value.

What is R 38 insulation used for?

10¼ ” thick, R-38C EcoTouch® Thermal Batt insulation prevents moisture damage and help assure long roof life by providing 1" of ventilation air space between the insulation and roof deck.