Some of the most common infestations found in blown in insulation are mold and mildew. Contaminated insulation can cause unhealthy indoor air quality throughout your home, and put you at higher risk of leaks and water damage.
Insulation needs to have room to expand to its full size to be effective, so the old definitely needs to be removed. Not to mention the old stuff is full of dust, probably some rodent excrement, and who knows what else that has accumulated in your attic over the years, so that's another reason to get rid of it.
When fiberglass insulation is moved or disturbed, it releases tiny particles into the air. If they get on bare skin they can lodge into pores and cause itching, rashes, or irritations. If they are inhaled, they can result in coughing, nosebleeds, and/or respiratory problems.
In many cases you can add new insulation on top of old insulation, unless the old insulation is wet, mouldy, or vermiculite. If the old insulation is dry but appears to have previously been wet, you should look for the cause and repair the problem.
Blown-in insulation can be installed in hard-to-reach places that roll insulation cannot, such as around pipes, electrical wiring, and other tight spaces. This allows for greater coverage and better insulation overall.
When blown-in insulation settles, your attic loses insulation performance. Settling compromises the R-value of your insulation.
Why Fiberglass Batt Is the Best Attic Insulation Material. Fiberglass batt is considered to be the best insulation for attics.
Mold and Mildew Growth
Having too much insulation in your attic can allow for the accumulation of moisture. This leads to mold and mildew growth, which can be extremely bad for your health.
Any reputable insulation installer will thoroughly remove old insulation before putting in the new. However, as a homeowner, you should double-check that they remove all of the old insulation as a first step.
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.
Blown-in insulation, available in fiberglass and cellulose varieties, generally lasts 20 to 30 years. Fiberglass tends to be the more durable option, while cellulose is more sensitive to humidity, which can affect its longevity in certain climates.
(R303. 1.1. 1) Blown-in or Sprayed Roof and Ceiling Insulation | UpCodes.
Blown-In Cellulose Particles Are Paper.
Unlike glass fibers, cellulose isn't dangerous to breathe. However, it can irritate your lungs. If you have pre-existing allergies, the dust of cellulose insulation can be obnoxious.
Cons of Blown-In Attic Insulation:
Poor installation can lead to uneven coverage, material waste, and even structural issues like sagging ceilings. Hiring a skilled installer is crucial to getting the most out of this insulation type.
Insulation that can't be removed by hand – Some types of insulation that fall into this category include blown-in foam insulation, loose fill fiberglass insulation, and cellulose insulation. Due to the scattered structure of these insulation types, they cannot be efficiently disposed of by hand.
Removing old insulation is generally recommended if it's damaged, contaminated with mold, or infested with pests.
The optimal R-value for most homes is 30, but you can go as high as 38 if you live in a tropical climate. Anything higher than 38 indicates an over-insulated space. While you might think that too much insulation can't be bad, there are some significant consequences to consider.
How Long Does Attic Insulation Removal Take? For a 1,500-square-foot attic, professional removal of blown-in insulation without hazardous complications can take as little as 4 to 6 hours to complete.
Blown-In Insulation (Fiberglass And Cellulose)
In most homes, loose-fill insulation can survive anywhere from 80 to 100 years before needing replacement, provided that it is not damaged.
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.
Fiberglass is by far one of the most thoroughly tested building materials and can be installed in the form of batt or blown-in insulation. Fiberglass is eco friendly, non-flammable, safe to install and maintains its thermal performance for the life of the building.
You can choose from different materials like cellulose (made from recycled paper), fiberglass, or mineral wool. Cellulose is an eco-friendly and cost-effective insulation for attics. Fiberglass and mineral wool are also popular choices because they are good at keeping heat in or out and resist moisture and pests.