How Does Insulation Directly Affect The Air In My Home?

Attic insulation, check? Although having attic insulation is a great start, most people don’t take the time to assess and understand if their attic insulation is still effective and sufficient to not only protect a home from external conditions but also ensure it is not contributing to poor indoor air quality within the home. There are many causes of poor indoor air quality, some of which insulation protects against, and others that poor insulation can actually cause if the insulation’s condition is not checked regularly. Some signs of poor indoor air quality that can be caused by ineffective or old insulation are allergy-like symptoms (sneezing, runny nose, itchy throat, etc.), strange smells or odors, sounds or signs of pests, and breathing problems, among others. Good Home Insulation is here to help you check the quality of your insulation and be a part of the solution to bringing cleaner and fresher air into your home. Schedule a visit with us today

How Insulation Can Lead to Poor Air Quality 

Understanding how your insulation can impact your indoor air quality is an important yet often overlooked aspect of being a homeowner. Whether your home has the proper levels of insulation at R-30, R-38, R-49, etc. is only part of the solution to ensuring it is doing its job in protecting your home. Some of the most common issues can happen over time even if insulation is well cared for and others are the result of unwanted moisture and pests that find their way into an attic. 


All good things must come to an end…even insulation sometimes needs to be replaced after it has served its purpose for many years! Over time, certain types of insulation like blown-in fiberglass can settle and/or accumulate dirt and other particles leading to it becoming compressed, reducing its R-value and therefore its effectiveness in protecting your home. The most visible signs of these issues’ impacts on indoor air quality can be increased air leakage from the attic that either brings a draft or dustiness along with it. Just like another regular spring cleaning around the house, the attic is another place to regularly ensure dust and dirt accumulation doesn’t find its way into the home!

Moisture & Mold 

Another culprit for insulation damage and poor air quality is too much moisture which not only will reduce the effectiveness of the insulation but also can lead to mold growth. If left alone and mold or bacteria begins to grow, it can put off spores and particles into the air that can cause serious sickness. This is why the EPA recommends removing insulation that has been impacted by too much moisture and replace with new. Before replacing insulation, however, it’s also important to address the root cause of any excessive moisture whether that be a leaky pipe, condensation, roof leak, etc so that the new insulation does not suffer the same deterioration. 


No one likes the thought of unwanted critters or pests making a home in their insulation…but you can’t blame them for finding a soft and warm place for the winter! The impact of pests on insulation is often seen through what they leave behind in waste, dirt, or even worse if they don’t make it out alive. Much like mold, this can lead to odors and contaminated air that should be kept outside. Often in these instances, the insulation should be removed and replaced with new insulation once the pest problem has been addressed. 

Controlling Air Movement & Mitigation 

But shouldn’t the air in my attic be staying in my attic? Great question! The short answer is in most cases, yes. There are good forms of ventilation and airflow within a home that promote a balanced environment, but there is also air movement that should be controlled and stopped when not helping to ventilate in a cost-effective and healthy way. As an example, in naturally ventilated attics where soffits and ridge vents or gable vents are used, the attic air should not be entering your home in the first place as this air is unconditioned and works against the heating and cooling systems in your home to condition the indoor air. Let’s take a closer look at how air movement in a home works and then address how we can help replace any insulation that is not promoting a healthy air environment. 

Air Movement

Two fancy terms when talking about air movement within a home are the thermal boundary (the boundary around the home at which insulation is installed) and the air barrier (the boundary around the home at which air is sealed off between internal and external to prevent uncontrolled air leakage). Since these two boundaries are intended to be aligned and continuous around the home, that means that anywhere there is insulation, there should also be adequate materials to make the interior area airtight. 

Let’s think about this in regard to a naturally ventilated attic as mentioned previously. Most commonly used in these attics are blown-in fiberglass or cellulose insulation that lays on top of the interior space’s ceiling drywall (i.e. the attic floor). Properly installed drywall will create an airtight barrier, but there are many opportunities for cracks and gaps that can allow all that conditioned air to leak into the attic and bring in the unconditioned and potentially harmful air from the attic into the living space. A few of these examples are cuts and holes in the drywall for a ceiling fan, outlets, cables, ductwork, piping, etc. and if not properly sealed around increase that air exchange between conditioned and unconditioned spaces. 

Air sealing is one of the first priorities when addressing indoor air quality issues and ensuring that unconditioned air does not pass the air barrier. Once this is mitigated, we can move on to fixing issues with ineffective or harmful insulation. 

Replacing Insulation 

Once it has been determined that the current insulation in place is either no longer doing its job or is even causing harm to your home potentially from one of the issues above, the next step is to replace that with new insulation. While it doesn’t sparkle like a new appliance or increase your curb appeal, new insulation does more for the home than many realize! The insulation removal process looks different depending on the type and condition of the current insulation, but once that is out we will ensure that the problems that led to the deterioration of the current insulation are resolved before putting in new insulation. There are many different types of insulation to consider (blown-in fiberglass, blown-in cellulose, spray foam, etc.) and we would be happy to help you understand what those options are and make the best decision for your home. 

Now that you know the potential risk of your insulation’s impact on indoor air quality, what are the right next steps? It starts with assessing the current conditions, identifying any issues, drilling into the root cause, and creating a plan to bring cleaner and healthier air into your home. No need to do this alone, let us know how Good Home Insulation can help!

Good Home Insulation

We’re committed to saving you money and safely keeping your family comfortable all seasons of the year.

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