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.

Should I remove old attic insulation before adding 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.

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.

Is it possible to over insulate an attic?

Can you over insulate your attic? 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.

What happens if you over-insulate?

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.

How to Beef Up Attic Insulation | This Old House

Is it worth adding more insulation to my attic?

Installing attic insulation this winter is a worthwhile long-term investment because it can significantly decrease your heating bills. As an added benefit, when the hot D.C. temperatures come back, the attic insulation will also minimize your air conditioning bills.

Does stacking insulation increase R-value?

DIY Frequently Asked Questions / Can I stack insulation to get a higher R-value? Yes. For example, two R-19 batts can be stacked on each other to create R-38 insulation. You also can add loose-fill insulation on top of a bottom layer of batts.

Can you double up faced insulation?

If you have a layer of faced insulation installed facing the exterior of the home you can stack a layer of unfaced insulation without any problems. If you have a layer of unfaced insulation installed you can also stack another layer of unfaced insulation without issue.

Can you lay insulation over electrical wires in attic?

Yes, you absolutely can. You can lay insulation around the junction boxes as well. Making sure that the insulation is of a fiberglass material will not only ensure a fireproof setup but also reduce airflow from the home through the attic.

How often should you replace attic insulation?

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.

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.

Should old loft insulation be removed?

In most circumstances removing your old insulation isn't necessary and it can actually be quite beneficial to leave it. This is as most insulation will retain its thermal properties so leaving it in place will mean that you continue to benefit from it whilst also having an additional layer of insulation on top!

Is blown in insulation better than rolls?

The Differences Between Blown-in and Rolled Insulation

In terms of R-value, they tend to be equal, although you can choose rolled insulation with varying R-values depending on your needs and your budget. The lower the R-value is, the less effective it will be as insulation – although it will be cheaper as well.

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.

Is it worth doubling loft insulation?

With loft insulation, there is a law of depreciating returns, which means the first few centimetres of insulation will save you many times the cost of the installation, but each extra centimetre adds less value, to the point where it is no longer worthwhile to add any more.

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.

What thickness should attic insulation be?

The recommended level for most attics is to insulate to R-38 or about 10 to 14 inches, depending on insulation type.

How do I know if my attic insulation is bad?

Will insulating attic keep house cooler?

A properly insulated attic can benefit your home in many ways, beside just keeping the home at a comfortable temperature year round. The short answer, yes, insulating the attic is an effective way to keep your home cooler during the summer months.

Is spray foam in the 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 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.

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.