Can you put blown-in insulation over fiberglass insulation?

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.

Which is better blown fiberglass or blown cellulose insulation?

At 3.5 per inch of material, the R-value of blown-in cellulose is 23% better per inch than fiberglass batts! According to research done at the Oak Ridge National Lab, fiberglass loses up to 50% of its R-value in very cold conditions; making cellulose a better choice for homes in northern climates.

Can I mix blown-in insulation?

You can mix different types of blown-in insulation. Rather than removing and replacing previously installed material, you can blow in the same (or a different) kind of insulation to save money and time. You can also mix blown-in insulation with rolled fiberglass insulation instead of replacing it.

Can I put new insulation on top of old?

In short, yes—you can install new insulation over old insulation. Contact us to start your project, or keep reading to learn more about adding insulation to your home!

What are the disadvantages of cellulose insulation?

Cons of Cellulose Insulation

It generates a lot of dust during installation. It is heat-resistant and has a high R-value. Cellulose insulation is prone to sagging and settling. It is heavily treated with fire-retardant chemicals.

How long will cellulose insulation last?

20 to 30 years
Some studies have even shown that cellulose insulation can help to protect your home in a fire. Because it is made primarily of recycled materials, however, cellulose insulation does degrade over time. The typical lifespan is 20 to 30 years, with degradation beginning as early as 15 years after installation.

Can you put too much insulation in your 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.

Should I remove old blown in insulation?

Your insulation needs to be removed along with the droppings, as it’ll carry some of its toxicity if left in your attic. Removing old insulation and replacing it with new ones will not only rid your home from any rodent infestation and mold, but also improve its energy efficiency and overall air quality.

Does blown-in cellulose insulation settle?

Cellulose insulation, unfortunately, is most likely to settle. Over time, the aeration in cellulose insulation will decrease. This settling will cause cellulose insulation to lose up to 20 percent of its R-value. Furthermore, cellulose insulation is particularly vulnerable to moisture.

Do mice like cellulose insulation?

Rodents generally are not drawn to cellulose insulation, either. This is because it’s loose and tends to fall in on itself. It’s not ideal for burrowing and building a nest. You can pretty easily install cellulose yourself, but you have to rent a special machine to blow it into the walls of your attic.

Is blown-in cellulose insulation good?

With an attic, this type of insulation is just one option along with the other popular alternatives, fiberglass batts or blown-in fiberglass. But with enclosed walls, blowing in loose-fill cellulose insulation is still by far the most practical and cost-effective method.

How long does it take blown in cellulose to settle?

In fact, cellulose has the highest rate of settling rates at anywhere between 13 and 20 percent after installation. This settling continues over the weeks, months and years after installation and can cause severe energy efficiency issues if not addressed properly during the insulation.

How long does blown in fiberglass insulation last?

Blown-in insulation typically comes in two different types — fiberglass and cellulose. The material comes in large bags, which are emptied into a blower system. For attics and crawl spaces, it is blown in through the openings for the space. Fiberglass insulation typically lasts from 30 to 50 years.

Does blown in fiberglass settle?

Blown-in insulation made from rock wool or fiberglass typically loses between 2 and 4 percent of its insulating capacity due to settling. High levels of moisture in your attic can exacerbate this problem, causing insulation to settle more quickly than normal.

Is cellulose insulation good for attic?

What is R-value of blown in cellulose?

between 3.2 to 3.8 per inch
The R-value of cellulose is between 3.2 to 3.8 per inch of thickness.

How often should you replace blown in insulation?

Insulation experts recommend replacing after 15 years to assure it is doing the job you need it to. Any time you have a leak in the roof, check the insulation if it has been affected and replace it necessary.

Is cellulose insulation more expensive than fiberglass?

When comparing blown-in insulation, both fiberglass and cellulose are nearly identical in price, both costing around $0.70 to $0.80 per square foot for 6 inches of insulation. Fiberglass batts, however, are less expensive, costing on average $0.30 to $0.40 a square foot for 6 inches of insulation.

Is cellulose insulation cheaper than fiberglass?

This insulation is more expensive than fiberglass but is more fire-resistant, better at resisting moisture, mold, and pests, better at dampening sound, more efficient at insulating, and eco-friendly. Installing cellulose insulation is a challenging DIY home project, recommended only for experienced DIYers.

How thick should cellulose insulation be in attic?

Cellulose insulation should be 8-19 inches deep in your attic. Generally, the proper depth of cellulose depends on the following factors: Desired R-value. Insulation density.

Does cellulose need a vapor barrier?

Air / Vapor Barrier

With Modern’s Cellulose insulation, a vapor barrier is not recommended except in very cold weather or high moisture areas such as spas or pool buildings. However, many building codes do require an Air barrier or Vapor retarder to be installed.

How can you tell the difference between fiberglass and cellulose insulation?

Per square inch of insulation, cellulose has a higher R-value than fiberglass. What’s R-value? It’s a measurement of an insulation’s ability to block the movement of heat. The higher the R-value, the more insulative the material.