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Air Seal, Moisture, Air Quality: Why We Remove Old Insulation From Your Attic

One area in your home that benefits greatly from adding foam insulation is your attic. When RetroFoam of the Carolinas comes and sprays foam insulation in your attic, it is standard procedure to remove old insulation from your attic floor. Do you know why?
Remove Old Insulation

Maybe you are trying to go green. Perhaps you want to reduce the cost of your monthly energy bill. Maybe you want to live a healthier, more comfortable life. Whatever the reason is, you may be considering adding foam insulation to your home. One area in your home that benefits greatly from adding foam insulation is your attic. When RetroFoam of the Carolinas comes and sprays foam insulation in your attic, it is standard procedure to remove old insulation from your attic floor. You may be wondering why. Doesn’t two layers of insulation offer more insulative value than just one layer? This article aims to show why in this case, two layers aren’t better than one, and it has to do with three things: a tight air seal, moisture, and the air quality in your home.

Air Seal

One of its most significant benefits of foam insulation is that it creates an air seal. Creating an air seal means that the foam keeps air from being able to pass through your walls freely. Spray, and injection foam seal up the open spaces and fills every nook and cranny to ensure no air leaks.

Foam sprayed onto existing insulation in an attic creates a problem. To understand this, it is important to understand how an attic is vented. Your attic is vented with soffits at the base where your roofline meets the attic floor. This allows air to flow up into your attic from the outside. It is then able to flow up out of your attic through the ridge vent. When you foam your attic, you will be closing off these outside vents.  If you leave the insulation in the attic, it will be hard to foam all places where the attic was initially vented to the outside, especially the soffits. Even if you rake the existing insulation back, the spray gun emits a lot of air, blowing the existing insulation around. This makes it very hard to get a good air seal, and it minimizes the effectiveness of the spray foam.

Moisture

Once you spray your attic, the air in your attic will circulate with all of the air in your home. That means that the air in your attic will be more humid than the air outdoors. If you leave your existing insulation down, you will be creating an excellent place for the moist air to drop moisture. Warmer air can hold more water than cooler air. Once that air is cooled, the moisture in the air is released, creating condensation. If moisture is collecting in your existing insulation, it provides a great growing place for mold and mildew.

Air Quality

Once your attic roof has an air seal, the air in your attic will circulate with the air in the rest of your home. This means that the air will be pulled down through the attic floor. If you have your old insulation on your attic floor, the air has to pass through it, which can significantly affect the quality of air that you are breathing in your home. Years of dust, rodent remnants, mold, and mildew, will be circulating in that air. Not to mention the extra strain it will place on your HVAC units. It will be akin to your HVAC wearing a mask as it tries to pull air from the attic space through the old insulation.

As you can see, you will get the best quality when we remove the old insulation in your attic prior to adding spray foam insulation. This ensures that you get that proper air seal and it prevents issues that could potentially arise with mold and mildew growth. Removing the old insulation will also help your home have good air quality. Some other added bonuses are that it will keep your HVAC systems from overworking, and it will provide you with more storage space in your attic.

Contact us today if your interest is piqued and you would like to discuss adding foam to your home.

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