According to one estimate, 90% of total homes in the United States are underinsulated. Even more concerning, nearly half of every home built in the US and Northeast Pennsylvania was built with asbestos, and many older homes in the area have never bothered to replace it.
Insulation is not something you think about every day. If you have existing insulation, you may feel comfortable leaving it in place or even forgetting about it.
However, innovations in energy efficiency, varying weather patterns, and natural degradation of materials could mean that your insulation needs to be updated and working as originally intended.
Contact with moisture and destructive pests could sharply reduce the lifespan of your insulation, requiring replacement sooner than you expect.
Like any part of your home, your insulation must be replaced every few decades, depending on other factors. This guide will explain the average lifespan of common insulation materials and signs that your insulation is old or damaged and needs to be replaced.
Expected Lifespan of Common Types of Insulation
Most forms of insulation are rated to last anywhere from 10-100 years, depending on the type of material and other environmental factors.
Regardless of what type of insulation you have, it’s ideal to get your insulation inspected by a contractor every ten years to ensure that it’s in good condition and not exposed to damage from moisture, pests, or fire.
That said, here are the most common types of insulation found in homes in Northeast Pennsylvania and their expected lifespans.
1. Fiberglass Insulation
- Lifespan: 80-100 years in ideal conditions, but typically around 25 years on average,
According to the Builders Practice Survey, fiberglass batts comprised 52% of total insulation found in homes across the nation. Fiberglass is prized for its affordability and DIY-friendly installation.
While rated to last up to a century in ideal conditions, attic insulation with fiberglass batts can be especially susceptible to mold in humid conditions or when in direct contact with moisture.
Signs of degraded fiberglass insulation include visible mold growth or detachment from surrounding framing members when batts are installed.
2. Spray Foam Insulation
- Lifespan: 80 years, depending on the installation and environmental factors.
Spray foam is the most efficient and long-lasting form of insulation, so it carries a higher price tag. Nevertheless, it is naturally moisture-resistant and can even offer air-sealing qualities that prevent moisture, UV rays, and other debris from entering your home and degrading your insulation.
Spray foam’s longevity depends on its installation, which is why it is so essential to work with a professional contractor.
3. Cellulose Insulation
- Lifespan: 20-30 years, depending on environmental factors.
Cellulose is an eco-friendly insulation option made from recycled paper products treated with fire retardants. Highly energy-efficient and eco-friendly, cellulose is an economical option for businesses and homeowners looking to insulate their properties.
Cellulose insulation is typically blown in and settles over time, which may reduce its effectiveness. In addition, cellulose is naturally biodegradable, so even in ideal conditions, it must be replaced every few decades.
4. Mineral Wool (Rock Wool) Insulation
- Lifespan: 80-100 years.
Mineral wool, also known as rock wool, is made from natural or recycled materials and is prized for its fire-resistant and sound-dampening qualities. Typically found on worksites, rock wool insulation is highly durable but also more expensive than most forms of insulation.
One factor to consider is the high pH level of mineral wool insulation, which may make it more unstable under harsh environmental conditions.
5. Foam Board Insulation
- Lifespan: 50-100 years in ideal conditions.
While typically used with spray foam or other blown-in insulation, rigid foam boards can help add extra thermal resistance to your home and are easy to install. Rigid foam board can last for a long time but will naturally deteriorate, especially when exposed to moisture or UV light.
Factors That Impact Your Insulation’s Longevity
While insulation is rated to last decades under ideal conditions, most homeowners in Northeast Pennsylvania understand that climate conditions are not always ideal. From intense rains that flood homes to high humidity in the summer that invites in pests, there are several factors that can diminish your insulation’s longevity.
1. Moisture and Water Damage
Without a doubt, water is insulation’s worst enemy. Whether from a roof leak, flooding, pipe leak, or condensation buildup, moisture can compromise insulation’s ability to regulate temperature and lead to mold. Wet insulation, such as cellulose and fiberglass, can also degrade building members around it, necessitating replacement to avoid structural issues in your home.
2. Pests and Rodents
In Northeast Pennsylvania, pests like mice, squirrels, and even insects can nest in insulation and chew through materials. You will be able to easily spot insulation that rodents have damaged as it may be a cause of sudden drafts and energy bill spikes you were not anticipating.
3. Settling and Compaction
Blown-in materials, such as cellulose and fiberglass, can be subject to settling and compaction, reducing their effectiveness over time. While this does not always require replacement, it will produce noticeable ill effects in your home, such as drafts and higher energy bills.
4. Temperature Fluctuations
Extreme temperature changes can degrade insulation faster than expected in places that may be more exposed to the elements, such as attics, unfinished basements, and crawl spaces.
5. Installation Quality
Finally, poorly installed insulation will lead to gaps, air leaks, and reduced efficiency, thus requiring replacement at some point to maximize the insulation’s effectiveness. One note on why we strongly caution against DIY installation is that older homes with poorer ventilation may invite moisture buildup if insulation is not installed properly, leading to a whole host of problems.
Signs It’s Time to Replace Your Insulation
If you have insulation that is over a decade old or notice any of the following signs, it could mean that it’s time to inspect and replace your old insulation.
- High Energy Bills: If your heating and cooling bills have been steadily climbing despite no significant changes in usage or temperature shifts, your insulation may no longer be performing efficiently. Insufficient insulation forces your HVAC system to work harder, increasing energy costs.
- Uneven Temperatures: Do you notice that some rooms are too hot in the summer and too cold in the winter? Can you feel drafts that travel across one part of the room? This could be a sign of deteriorating insulation, especially in the walls or your attic.
- Visible Damage or Aging: A visual inspection will be able to point out any obvious signs of damage, such as water stains, mold, sagging, settling, or crumbling.
- Pest Infestations: Signs of pests, such as droppings or nesting material made out of or in your insulation, can mean the material has been compromised and needs replacement.
- Drafts and Cold Spots: Drafts or cold spots in your home suggest air leaks caused by poor or damaged insulation. In some cases, you may just need to properly air seal your home.
- Noise Levels: If outside or interior noise seems to travel louder and farther than usual, it could be a sign your insulation is not up to snuff.
Learn more about seven signs it’s time to replace your old insulation.
The Benefits of Replacing Old Insulation
We’ve discussed the benefits of new insulation numerous times on our blog, but it’s important to reiterate the benefits of replacing old or damaged insulation beyond the obvious benefits.
While removing insulation can be an added cost, you can greatly recoup these benefits down the road through increased energy savings and home value.
- Energy Efficiency: Newer and properly installed insulation will regulate temperature more effectively and create a noticeable reduction in your energy bills.
- Comfort: Proper insulation ensures consistent temperatures throughout your home, eliminating cold spots and drafts.
- Health: Damaged insulation can harbor mold, allergens, or pests, which negatively impact indoor air quality and harm your health.
- Home Value: Upgraded insulation improves your home’s energy efficiency rating, making it more attractive to potential buyers.
- Structural Protection: Wet or damaged insulation can cause damage to surrounding framing members, requiring immediate replacement to keep your home safe.
Understanding the average lifespan of your insulation and the factors that impact its longevity will help you determine if it’s time to move on from your old or damaged insulation. When that time comes, contact the experts at NEPA EnergySmart for a free quote and consultation!
FAQs
How often should insulation be replaced?
Insulation should be replaced when noticeable signs of damage or deterioration have taken place. We recommend inspecting your insulation every 10 years to monitor its condition and effectiveness.
Can I add new insulation over old insulation?
It is possible to add new insulation over old insulation if the previous insulation is in good condition and the home properly ventilated. In many cases, we add on spray foam insulation over existing rigid board or fiberglass to maximize its thermal resistance.
How much does insulation replacement cost?
Costs vary depending on the material, square footage, and labor. On average, insulation replacement ranges from $1.50 to $3.50 per square foot.