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Can You Add New House Insulation Over Old Attic Insulation?

Posted by First Quality Roofing & Insulation on Aug 14, 2020 5:13:04 PM

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Do you have old attic insulation? Are you thinking of adding new insulation to your home?

There is a good chance that your home already has insulation in the walls and attic; however, you might be concerned that your insulation might not be providing you with the same benefits that it once did. Therefore, you might be thinking of adding more insulation. Or, you might be thinking of removing the old attic insulation and adding new house attic insulation. Which option is right for you? Can you simply add new insulation to the old insulation that is already present?

To put it simply, yes, you can. When you are trying to figure out if you should add new insulation to your old insulation in your Las Vegas home, there are some situations in which you can leave the old insulation in place. In other situations, you might need to replace the existing insulation. What are a few of the factors that you need to keep in mind?

Signs You Need New Attic Insulation

First, it is important for you to think about some of the signs that you need new insulation in your attic. Some of the most common signs include:

  • Your Indoor Temperatures Are Changing: First, if you have noticed a draft in your home, this could be due to your old attic insulation. Over time, attic insulation will shift. The shifting allows outdoor air to enter your home to compromise your heating and cooling system’s ability to adequately regulate the indoor temperature of your home. This could lead to drafts even when doors and windows are closed.
  • Climbing Utility Bills: Are you noticing that your energy bills are rising? The most common culprit is that your HVAC unit is working harder than it has in the past. As a result, your HVAC unit is drawing more electricity, leading to climbing utility bills.
  • Pest Infestations: If your insulation is dirty, this is a prime place for pests and rodents to build a nest. You might even notice bats and birds in your attic. If your home has been invaded by these animals, then you probably need to replace your attic insulation. Even if you can remove these pests, the feces they leave behind can place your health at risk.
  • Mold and Mildew Growth: Finally, if your attic insulation comes into contact with moisture from a leaky roof or the absence of vapor barriers, then the insulation will quickly fall apart, losing its value. Furthermore, wet insulation can lead to the growth of mold and mildew, which will put your family’s health at risk.

These are a few of the most common signs that you need new attic insulation. Now, the question is whether you should remove the old attic insulation or simply add new insulation on top. How do you decide?

Adding New Insulation: When to Do It

In general, you can place new attic insulation on top of existing insulation as long as the current insulation is not wet. When you look at the current insulation, if it is wet, then it needs to be removed. First, you need to figure out why the insulation is wet. This could be due to a leaking roof or ceiling rafters that are rotting. Then, you need to see if mold and mildew are present. If they are, then the mold and mildew need to be removed along with the old insulation. Then, new insulation can be put down.

In addition, if your insulation is particularly old, then it might contain asbestos. This material should not be disturbed, and it has to be removed by trained professionals. If you inhale asbestos, it can lead to severe lung disease. There is no safe level of asbestos exposure, so this has to be removed by trained professionals.

In summary, you can add new insulation on top of existing insulation if:

  • The old attic insulation is not wet
  • There is no mold or mildew present
  • There are no vermin in the attic
  • There is no fecal matter in the old insulation
  • There is no asbestos present in the insulation

As long as you meet these requirements, you can add new insulation on top of old attic insulation. Now, how should you add your new insulation?

A Review of the Best Practices for Adding House Attic Insulation

There are a few best practices in the industry that have to be followed in order to ensure that new attic insulation is added correctly. These include:

  • Whole-house Air Sealing: This is the most important first step that should always be taken before installing new insulation. When the house is sealed, it will reduce the amount of air leakage. Using whole house air sealing can make the home more comfortable.
  • Vapor Barriers: Vapor barriers can help you extend the life of your insulation because they keep moisture and humidity at bay. When new attic insulation is installed, the vapor barrier should not be installed on top of any other insulation. Otherwise, this will have the opposite effect, leading to condensation and moisture in an area that is supposed to remain dry. 
  • Roll or Bat Insulation: This type of insulation can be installed on top of existing insulation as long as it is installed perpendicular to joists. A joist is a horizontal member that runs across the building. Furthermore, roll or batt insulation should not be tacked down. If it is compacted, it reduces its value.
  • Loose Fill Insulation: if you are using loose-fill insulation, then this can be added on top of old insulation with ease. This is one of the most popular types of insulation because it is easy to install.

These are a few of the most important practices that have to be followed when it comes to installing new attic insulation. When it comes to house attic insulation, how long should it last?

How Long Does New House Attic Insulation Last?

A little bit of online research will quickly show that attic insulation should last for 100 years. Of course, this is under perfect conditions, which are hard to find. In general, house attic insulation will last around 15 years. Some of the factors that will either shorten or lengthen its life include:

  • Leaking roofs can quickly shorten the life span of attic insulation
  • Air leaks in the attic allow heat, cold and water to seep in, shortening the life span of the insulation
  • If critters invade the attic, they will shorten its life span as well
  • The growth of mold and mildew will also shorten the life span of attic insulation

In order to prevent these problems from reducing the lifespan of your attic insulation, you need to rely on trained professionals for help. That is where we come in.

Update Your Old Attic Insulation Today!

If you are looking for professionals who can help you update your old attic insulation in Las Vegas, then you need the help of First Quality Roofing & Insulation. Contact us today to learn more about how we can help you with your insulation needs!

Topics: attic insulation



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