Does Existing Attic Insulation Need To Be Replaced Before Adding New Insulation?

You may not need insulation removal service unless the following applies:

  • There is fire or / water damage (insulation needs to be removed to prevent mold growth)
  • There is untreatable mold  on your attic insulation
  • You have a substantial animal infestation from chipmunks, mice, squirrels, chipmunks, or raccoons.
Insulation removal 3 loose fill fiberglass removal attic contractor chicago
Fiberglass Insulation Removal Attic

Do I need to replace the current insulation? Odds are, most likely not.

You may not need insulation removal service unless the following applies:

  • There is fire or / water damage (insulation needs to be removed to prevent mold growth)
  • There is untreatable mold  on your attic insulation
  • You have a substantial animal infestation from chipmunks, mice, squirrels, chipmunks, or raccoons.

In these situations, it is recommended to vacuum, offsite disposal and disinfection. If that’s the case there are funds available to you if you have asbestos from a zonolite plant. (https://www.zonoliteatticinsulation.com)

A professional will also disinfect the attic space before and after the insulation is removed to reduce contaminants in the rest of the home. Home insurance may cover the cost of removing and reinstalling your attic insulation for the situations listed above if it is included in your home policy.

If you have a mold infestation, it is possible for your existing attic insulation to remain in the house as long as there are no signs of mold growth on the insulation and the insulation is treated at the same time as the rest of the attic to kill all the mold spores and prevent it from regrowing.

Existing insulation can remain and benefit your retrofit attic upgrades in 4 ways 

  • increased r value 
  • decreased removal costs
  • decreased labor and material costs
  • less landfill 
mold removal green attic

Insulation That Has Settled

You may be wondering if you need to replace insulation that has settled. Even if your existing insulation has settled, you can leave it in place and simply have insulation added on top of it (as long as it does not have any of the previously mentioned deficiencies). Insulation that has settled still has thermal resistive properties that add to the overall R-value once new insulation is added. 

By leaving the old insulation intact, you are also leaving the original vapor barrier intact, as long as it was installed properly during the original installation. However, air sealing the attic floor with fireproof foam will need to be done before new the insulation is installed to increase efficiency and prevent moisture from inside the house.

Insulation With A Vapor Barrier

If you have fiberglass batts in your attic, there is a good chance there is already a vapor barrier, as most of these batts have a thick piece of heavy-duty paper on one side, specifically designed to act as the vapor barrier.

For blown-in fiberglass insulation, you should see a plastic membrane or other vapor impermeable material installed to help stop the exposure of moisture to your insulation. Moisture will reduce the R-value (a measure of thermal resistance) of your insulation over time. This is another reason it is important to have a professional inspect your attic to ensure your vapor barrier is not damaged or missing.

When using blown-in cellulose insulation, a vapor barrier is not needed as it acts as a natural vapor barrier and will restrict the flow of vapor in the attic. It is always important to make sure the attic is properly ventilated to decrease moisture build-up. In some cases, it may be necessary to add supplemental ventilation in the form of an attic vent/fan.

For new construction and situations where insulation needs to be removed, a professional should air seal with fireproofing foam at all of the gaps in between the drywall and the framing members in the attic. After the gaps are sealed, they will install the baffle for proper ventilation and install up to 16-18 inches of cellulose to get an initial R-value of R60.

All insulation will settle, so an experienced professional will know to compensate for the settling by installing an extra 2 inches of cellulose insulation. Extra insulation will also be valuable in any future work that needs to be done in the attic as it can be disbursed to the areas that are worked on.

Blown-in Insulation Pros'/ Con's

Blown-in insulation is a great option as it covers the area more effectively than bat fiberglass. A professional will blow in the material through a 3-inch hose and completely cover the attic floor, encapsulating the ceiling joists. This is important because wood has a low R-value, meaning it transfers heat very easily. By encapsulating the floor joist with insulation, thermal bridging (the transfer of heat) is eliminated making the insulation more effective.

The most common types of blown-in insulation are fiberglass and cellulose. Cellulose is a great alternative to blown-in fiberglass insulation because it is healthier, eco-friendly, and will resist mold growth while having similar, if not greater thermal resistive properties (higher R-value) than blown-in fiberglass insulation. Cellulose insulation is also a natural vapor barrier and will save you on the additional expense of removing insulation. Blow-in fiberglass is made out of rigid fibers and doesn’t stop the moisture or air leaks. Blow-in fiberglass also requires a continuous moisture barrier.

Removal of Spray Foam in Attic

Although spray foam insulation is popular and applicable in many situations (such as commercial metal roofs), there can be serious problems if it is not applied properly. Even when it is applied properly, there are many situations where spray foam is not the most appropriate product to be used on the attic rafters. Many spray applied foam insulations pose fire hazards and make it hard to identify roof leaks since spray foam is applied to the underside of the roof decking.

If your foam insulation in the attic smells bad, it may have been applied at the wrong temperature, installed too thick, or not applied properly at the time of installation. Another cause for complications with spray foam in the attic is roof leaks. Spray foam insulation can cause the water to be trapped between the foam and the roof decking, creating a potential for the roof decking material to rot. It is imperative to have it removed and replaced if there has been water damage.


Thanks for reading, we hope this  helped answer ?s reguarding you need to remove your existing attic insulation before adding new insulation. Properly installed insulation is one of the many factors in maintaining  healthy air quality, comfortable solar power ventilated, energy-efficient home. If you are having comfortability issues and high energy bills, it may be time to call a professional to assess your attic space.

Insulation Removal = Start Fresh

https://greenattic.com/insulation-cost-compare-4-types-of-materials-rvalue/Insulation is material used that reduces heat loss or heat gain by providing a barrier between the inside of your home and the significantly different temperature outside.

Attic insulation removal cost is between $0.75 and $1.75 per sq.ft. depending on the type of existing insulation, sq.ft. of the house and roof type.

Talk with our specialists and schedule a free inspection to determine if your insulation needs to be removed. 

You do not need insulation removal service unless the following applies:

  • There is water damage (insulation needs to be removed to prevent mold growth)
  • There is mold growing on your attic insulation
  • You have a substantial animal infestation.

It’s first important to understand where your house is losing air and the best route to fix this problem. We handle that for you and even show you our process and the results! Contact us today to find out if you need our insulation removal service.

can existing insulation stay in your attic? 

Yes, keep it, if not damage or contaminated.

The answer depends on these factors. 

  1. Feces
  2. Urine 
  3. Fire or Water Damage

See picture below, prep-work complete for two skylights, two bath fans multiple can lights and an entirely air sealed attic floor. 

Jenny Levine
Jenny Levine
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Our attic is unfinished and isn't easy to get to. David came out to check on the insulation and gave us an honest assessment that it had held up well after 15 years and there wasn't anything he could do for us at this time. We really appreciated this and will definitely use Green Attic when we do need to add more insulation.
Kobey McCall
Kobey McCall
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David really goes above and beyond. Great communication and really professional. Took the time to really explain the process and scope. Competitive pricing, good rebates, good quality. Would absolutely recommend.
Claire Mallory
Claire Mallory
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Tim came out to do an energy audit, and had lots of specific recommendations for how to make our very leaky house less leaky - much of which we were able to do ourselves. Insulating the attic was high on the list, and Romulo and his crew did a fabulous job. They were quicker than expected, super professional, and made sure I was happy with the final result. Highly recommend Green Attic all around!

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