How do I increase the R-value in my attic?

To increase the energy efficiency of your home, you can boost the R-value of walls by adding more batt insulation between wall studs or installing foam-board insulation. You can also use blown-in insulation to fill any gaps where drafts can occur.

How do I make my R-value higher?

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. Foam board insulation is easy to install between wall studs and over existing blanket insulation.

Does doubling the insulation increase the R-value?

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.

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.

Does insulation lose R-value over time?

Yes. Cellulose insulation does lose its R-value when it is compressed. The amount of loss depends on how much insulation is decompressed but typically ranges anywhere from 15% to 20% of its initial value.

Improving R-value with Radiant Barrier Over Insulation

Can you put 2 layers of insulation in attic?

You should install two layers of insulation in your attic; wood joists must be covered to allow the air to move. The first layer will sit between the joists, and the second layer will run perpendicular over the joists. The first layer should have the facing against the drywall to act as a vapor barrier.

Can I put new insulation on top of 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.

Can you have too much R-value?

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.

Do I need to remove old attic insulation before installing new?

Expert contractors that specialize in insulation advise that removing old fiberglass insulation is best before installing new cellulose insulation because of possible mildew, mold, or rodent excrement.

When should you add more insulation in attic?

All you need is a yardstick or tape measure, and maybe a flashlight if you don't have adequate lighting in the attic. From the attic hatch, look around in every direction. If you can see the floor joists – boards about eight inches high spread a few feet apart across the attic floor – you probably need more insulation.

Which insulation is best for attic?

Many people consider fiberglass batt to be the best attic insulation. It consists of plastic reinforced by small glass fibers. The batt version comes in blanket form — i.e., small, pre-cut sections that you can lay down wherever you need to.

What type of insulation has highest R-value?

The type of insulation with the highest R-Values, with a few exceptions, is rigid foam or panel insulation. Also called “foam board” or “continuous” insulation. Most varieties of this type of insulation consist of expanded foam sandwiched between two rigid panels.

How can I maximize my house insulation?

How often should attic insulation be replaced?

As a general rule, insulation should be replaced or retrofitted every 15 to 20 years. However, it may need replacing or retrofitting sooner depending on the type of insulation installed, the R rating of the original insulation, compression and movement over time, and whether any damage has occurred.

Can you put insulation batts over loose fill?

A: There's no problem with installing fiberglass batts over your existing blown-in insulation. The only thing you want to make sure of is that you use "unfaced" insulation, meaning it doesn't have a paper or aluminum foil facing on the batts.

What is better batts or blown-in insulation?

Practical and durable: When comparing batt insulation vs. blown cellulose, keep in mind that batt insulation is a more effective thermal barrier. The thermal performance of loose fill insulation will not last for the life of the building. Most blown-in insulation materials will settle and lose R-value over time.

Should I insulate my attic floor or ceiling?

roof insulation is no-contest. The floor wins every time. Insulating the floor is standard practice for an unfinished attic space. The exception to this rule takes place when families opt to convert an unfinished attic space into something usable or livable.

Is spray foam insulation in attic worth it?

A properly done spray foam job not only insulates but also greatly reduces the air leakage of a home. But that only works if the installer can get it into the places where most of the air leakage happens. In an attic, the eaves are one of the most critical places to get good coverage with the foam.

Should you insulate attic roof rafters?

Insulating between rafters will do no good, because the attic should be ventilated, and the rafter insulation would be between two unheated spaces. You can add insulation to the floor; the more the merrier. Just don't put it in the eaves. Also, make sure the attic is well ventilated.

How long does blown-in attic insulation last?

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.

Is it worth replacing old fiberglass insulation?

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.

Which type of insulation is most effective?

Q. What is the most energy efficient wall insulation? Closed cell spray-foam insulation is the most energy efficient wall insulation. Applications can reach much higher R-values for each inch of thickness than other insulation products, with values as high as R-6.2 per square inch (roughly R-34 on a 2×6 wall).