Removing old insulation is generally recommended if it's damaged, contaminated with mold, or infested with pests. However, if the insulation is in decent shape and just needs a boost, adding a new layer on top can be a cost-effective option.
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.
Condition of Existing Insulation: - If the old insulation is in good condition (not wet, moldy, or damaged), it may be acceptable to leave it in place. However, if it shows signs of deterioration or contamination, it should be removed.
Call your local waste-management office and ask what to do with the insulation of your type. In some cases, you can place the bags out with your regular trash. In others, you will have to take it to a designated area at the dump.
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.
With all factors considered, the average attic junk and insulation removal costs around $1.50–$3 per square foot. If there's mold present, however, costs lean toward the top of that range or over — approximately $4.5–$6 per square foot.
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, 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.
If you have fiberglass insulation you would like to recycle, call your local recycling facility to see if they can handle it. If not, they may know the nearest facility that can take your insulation.
It's going to get everywhere and make an even bigger mess, so you will need to get a vacuum to remove insulation from the attic. We use a 1,500-horsepower shop vac when we do the removal, and in most cases, hook that to a second attic insulation removal vacuum to get the suction we need.
Unfortunately, the majority of homes built 50 years ago were not insulated at all. It is important to be aware of these insulation issues if your home is 50+ years old. Replacement (or new installation) may be necessary if your home is drafty, if you have high utility bills, etc.
In fact, homes with unfinished attics may have no rafter insulation at all — instead, they rely on fiberglass batts or blown insulation installed between the joists on the floor. In either case, though, your insulation should generally remain untouched while the roofer does their job.
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.
When blown-in insulation settles, your attic loses insulation performance. Settling compromises the R-value of your insulation.
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.
Indoor air quality: You can improve the air quality in your home by removing old insulation that may harbor mold, dust or allergens. Increased home comfort: New insulation helps regulate indoor temperatures more effectively, eliminating hot or cold spots and even reducing noise.
Most recyclers will let you know how they prefer to receive your old insulation, so check with them before heading off. Remember, the only types of insulation you can recycle are natural fiber and mineral wool insulation. You will need to drop off all other types at your local waste disposal center.
Expect costs of between $1 and $2 per square foot to remove insulation, with blown-in varieties near the lower end and rigid types near the top end. Keep in mind that those prices are for dry and in good condition non-asbestos insulation.
Moisture Sensitivity: One of the major drawbacks of blown-in insulation is its susceptibility to moisture. If your attic has a moisture problem or experiences water leaks, the insulation can become damp, leading to mold growth and reduced effectiveness.
While it varies by type, blown-in cellulose is a type of insulation that can typically be recycled. The blower tool deploys the material to fill wall cavities, making it ideal for hard-to-reach spaces and poorly insulated areas in attics or crawl spaces.
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.
The Process for Blown-in Insulation Removal
Follow these steps for blown-in insulation removal: Set up the insulation removal vacuum and run the hose to the attic. Climb into the attic to resume the removal process. Suck out the insulation from the walls and use a rake and dustpan to clear any remnant debris.
Generally speaking, replacing old insulation may not be worth it if old insulation is dry, free of dust and it is not squashed. In this case, its removal isn't necessary. In fact, it can be quite beneficial to leave old insulation.
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.