How long does blown in attic insulation last?

Asked By: Djiguiba Roffey | Last Updated: 19th June, 2020
Category: home and garden indoor environmental quality
3.9/5 (355 Views . 40 Votes)
Blown in cellulose insulation will last anywhere from 20 to 30 years under ideal conditions. There are many factors that affect the lifespan of blown in cellulose which is why you need to make sure that it is installed professionally from the beginning.

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Also question is, how long does Attic Insulation last?

Typical Insulation Lifespan The International Association of Certified Home Inspectors states that spray foam insulation, wrap tape and housewrap insulation can last for more than 80 years. At the same time, cellulose, loose-fill, foamboard, loose fill and rock wool insulation can last up to 100 years.

One may also ask, does blown in insulation settle over time? Blown insulation settles over time, becoming less effective. Over time, blown-in insulation will settle and lose these air pockets, reducing its effectiveness. The amount that your blown insulation will settle depends on the material it is made from.

Furthermore, how often do you need to replace attic insulation?

Insulation should also be replaced, in some cases sooner than 15 years, if it is no longer doing its job properly. You'll know it needs to be replaced if there are insulation leaks or if it is peeling from the walls.

What is the best type of blown in attic insulation?

The best insulation options for an attic are open cell spray foam, fiberglass, and cellulose.

  • Cellulose is the oldest insulation material used for not only the attic, but other areas of the home as well.
  • Fiberglass is another traditional insulation material that consists of extremely fine glass fibers.

34 Related Question Answers Found

Can you have too much insulation in your attic?

Without proper ventilation, a home can build up too much moisture, especially in the attic (warm air rises), which can cause mold problems and, overall, lower indoor air quality. This is not to say that if you have mold in your home, too much insulation is the culprit.

Should old attic insulation be removed?

Remove Old Insulation
Once there is no asbestos, mold, or rodents, it is generally safe to proceed with attic insulation removal yourself. Some insulation is easier to remove than others. Luckily homeowners are more likely to find the easier kind which is blown-in fiberglass or cellulose insulation.

How many inches of insulation should you have in your attic?

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

Can I put new insulation on top of old?

According to ENERGY STAR®, you can put new insulation over old insulation, “unless it is wet. The vapor retarder on top of or between layers of insulation can trap moisture. Any existing batt or roll insulation in the attic should have the facing against the attic drywall floor or no facing at all.

How much does it cost to redo attic insulation?


It can cost anywhere from $1,700 to $2,100 or between $1.50 and $3.50 per foot to insulate an attic depending on what insulation material you choose. Blown-in insulation is the least expensive option and ideal for older attics. Spray foam, while the most expensive, is best for noise reduction and new construction.

Is it worth replacing old insulation?

Even old newspaper insulation will still keep much of its thermal properties, so unless you need to remove the insulation for other reasons, it isn't worth taking the insulation out for efficiency reasons alone. There are clearly reasons why you would want your insulation removed, but efficiency isn't one of them.

How do you know if you need more insulation in your attic?

A quick way to see if you need more insulation is to look across your attic floor. If your insulation level is at or below the top of the floor joists, you probably need to add more insulation (but remember to seal the air leaks before you insulate).

Is blown insulation better than rolled?

As you can see, both rolled insulation and blown-in insulation are good options; however, blown-in insulation does have a few more advantages going for it, including ease-of-use and the ability to insulate hard to reach areas.

How do you tell if your house is well insulated?

Do the touch test. The interior ceilings, walls and floors in your home should feel warm and dry. When drywall and paneling inside a home feels damp or cold, there is not enough insulation. Alternatively, when touching an exterior wall, it should feel cold because insulation is keeping warm air inside a home.

How can you tell if insulation is bad?


A simple way to test if your walls are under-insulated is to do the touch test. “Interior walls, floors and ceilings should feel warm to the touch and dry,” says Azari. “If it feels cold, damp or shows any moisture, that's a sign of heat loss due to under-insulation or cracks.”

How do I remove loose insulation from my attic?

Even with a dust mask or respirator, keep exposure to insulation at a minimum. Another option for loose insulation removal is to rent a HEPA filtered industrial vacuum. These high-powered vacuums do two jobs. First, the machine sucks up the loose insulation.

Does attic insulation wear out?

Attic insulation can become worn out over time, leaving cracks or holes that can be easy access points for moisture to enter in. This may cause the attic to be damp, which can beget the growth of mold and mildew.

Is blown in insulation cheaper than batts?

Blow-in insulation is quite comparable in cost and R-value when compared to fiberglass batts or blankets. DIY-friendly. Blow-in insulation is difficult for DIYers, especially for wall cavities. Attic insulation can be a DIY project with a rented or borrowed blower but is still a challenge.

How thick should cellulose insulation be in attic?

For loose-fill cellulose, this translates to a total depth ranging from 8 inches up to 16 inches. Fortunately, attic insulation can be upgraded simply by adding more to achieve the recommended total depth in inches, without removing existing insulation.

How much does blown in insulation cost?


Blown-in insulation is about $1,443, with most homeowners spending between $927 and $2,025, but this is dependent on whether the work is done by the homeowner or by a professional. Blown-in insulation (also called loose fill) runs from $1 to $1.50 per square foot.

Is blown in insulation any good?

Blown-In Insulation is a Good Investment
Adding loose-fill insulation to your attic is one of the fastest paybacks of any home improvement project. The amount of money you save on energy costs will add up quickly over the next couple of years, more than paying for itself, and even bringing a return on your investment.

Is Breathing cellulose insulation bad?

There are no dangers of very fine fibres entering your breathing system or causing any long-term damage if inhaled. This is the case with alternative products such as fibreglass insulation but not with cellulose.