The internet is full of advice about home insulation—some of it good, much of it questionable, and a surprising amount of it completely wrong. These myths persist because they sound reasonable, get repeated often enough that people believe them, or because they conveniently justify not spending money on insulation upgrades.
The problem? Believing these myths costs North Carolina homeowners real money—through higher energy bills, uncomfortable homes, and wasted spending on ineffective solutions. Let's bust the most common insulation myths so you can make smart decisions based on facts, not fiction.
Myth #1: "Insulation Is Only Important in Winter"
The Myth
Many homeowners think insulation's sole purpose is keeping homes warm in winter. After all, that's when we notice cold drafts and see our heating bills spike. So logically, insulation must be a cold-weather solution, right?
The Reality
Insulation works year-round by resisting heat transfer in BOTH directions. In winter, it prevents heat from escaping your warm home. In summer, it prevents heat from entering your cool home. It's a thermal barrier, not a one-way warmth keeper.
For North Carolina homeowners, summer performance might actually be more important than winter. Our cooling season (May-September) is longer and more intense than our heating season. Your attic insulation working overtime in summer to keep heat out directly impacts your biggest energy expense: air conditioning.
The Cost of This Myth
Homeowners who believe this myth might:
- Skip insulation upgrades because "we don't get that cold here"
- Wonder why their AC runs constantly despite being "warm enough in winter"
- Waste money on other cooling solutions instead of addressing inadequate insulation
When your attic reaches 145°F on a July day and you only have R-15 insulation, you're essentially trying to air-condition your home while a heat lamp shines from above. That's expensive.
The Fix
Proper attic insulation (R-49 for North Carolina's Climate Zone 4) creates a thermal barrier that protects you from summer heat AND winter cold. Combined with a radiant barrier, you're addressing both conductive and radiant heat transfer for maximum year-round efficiency.
Myth #2: "More Insulation Always Means More Savings"
The Myth
If R-49 is good, then R-60 must be better, right? And R-100 would be amazing! More is always better when it comes to insulation—it's a simple numbers game.
The Reality
Insulation follows the law of diminishing returns. Each additional R-value provides smaller incremental benefits. The difference between R-0 and R-19 is huge. The difference between R-49 and R-60 is barely noticeable. And the difference between R-60 and R-100? You'd need sensitive equipment to measure it.
For North Carolina homes, R-49 is the sweet spot. Going beyond that shows minimal return on investment. Here's why:
- The first inches of insulation provide the biggest impact
- Each additional inch provides less benefit than the one before it
- Beyond R-49, you're spending more money for negligible energy savings
- Extreme insulation levels can actually create moisture problems if not properly managed
The Cost of This Myth
Homeowners waste money by:
- Over-insulating beyond optimal levels
- Spending thousands on upgrades that won't deliver meaningful ROI
- Ignoring other important improvements (air sealing, ductwork) to fund excessive insulation
The Fix
Hit the recommended R-value for your climate zone (R-49 for us), then invest additional money in other efficiency improvements that deliver better ROI: air sealing, ductwork repair, HVAC upgrades, or radiant barriers. A balanced approach beats over-investing in one area.
Myth #3: "Insulation Stops Air Leaks"
The Myth
"Just blow in more insulation and it'll seal up those drafts." Many homeowners believe insulation and air sealing are the same thing, assuming insulation will plug air leaks automatically.
The Reality
Most insulation types are designed to slow heat transfer, NOT to stop air movement. Fiberglass and cellulose insulation work by trapping air in tiny pockets—but air can still flow through them. It's like wearing a loosely-woven sweater: it provides warmth, but wind passes right through.
Air leaks are separate from inadequate insulation, and they can undermine even the best insulation job:
- Gaps around recessed lighting: Insulation covers them, but air flows freely
- Attic hatches: Insulation on top doesn't seal the edges
- Plumbing and electrical penetrations: Air flows through gaps around pipes and wires
- Ductwork connections: Leaks allow conditioned air to escape
According to ENERGY STAR, air sealing alone can save up to 20% on heating and cooling costs. But you won't see those savings just by adding insulation without also sealing leaks.
The Cost of This Myth
This myth costs homeowners in two ways:
- Paying for insulation upgrades that underperform because air leaks weren't addressed
- Continuing to waste money on energy bills despite having "good insulation"
It's like wearing a winter coat with the zipper open—you're insulated, but cold air rushes in anyway.
The Fix
Air seal FIRST, then insulate. A comprehensive attic job should include:
- Seal all penetrations, gaps, and bypasses
- Weatherstrip attic hatches
- Install baffles to maintain ventilation while sealing soffits
- THEN add insulation
Professional installers know to do both. DIYers often skip air sealing because it's tedious—but it's absolutely critical for performance.
Myth #4: "All Insulation Materials Perform the Same"
The Myth
"Insulation is insulation. Just buy whatever's cheapest at the big-box store." After all, they all have R-values listed, so R-19 is R-19, right?
The Reality
Different insulation types have dramatically different characteristics beyond their R-value:
Fiberglass batts:
- Cheap and DIY-friendly
- Only works if installed PERFECTLY (gaps destroy performance)
- Doesn't block air movement
- Can sag over time
- Poor at conforming to irregular spaces
Blown-in cellulose:
- Excellent gap-filling
- Good air sealing properties
- Can absorb moisture (problematic in humid climates)
- Settles up to 20% over time
- Combustible unless treated
Blown-in fiberglass:
- Won't absorb moisture
- Excellent gap-filling
- Pest and mold resistant
- More expensive than cellulose
- Better performance in humid climates like NC
Spray foam:
- Highest R-value per inch
- Provides air sealing AND insulation
- Expensive upfront
- Requires professional installation
- Permanent (can't be easily removed)
The Cost of This Myth
Homeowners lose money by:
- Choosing cheap batt insulation for DIY, then installing it imperfectly (losing 30-40% performance)
- Selecting cellulose in humid climates where it absorbs moisture and settles
- Overpaying for spray foam when blown fiberglass would work fine
The Fix
Match insulation type to your specific application:
- Attic floors in NC: Blown fiberglass or cellulose (professional install)
- Crawl spaces: Spray foam or encapsulation
- Rim joists: Spray foam
- Walls (new construction): Batts, blown-in, or spray foam
- Walls (retrofit): Blown-in or injection foam
For North Carolina's hot, humid climate, we recommend blown-in fiberglass for attics—it won't absorb moisture, fills gaps completely, and performs consistently over decades.
Myth #5: "New Homes Don't Need Insulation Upgrades"
The Myth
"My house was built in 2015, so the insulation is fine. Building codes ensure new homes have proper insulation." Sounds logical—building codes improve over time, so newer homes must be better insulated than older ones.
The Reality
While it's true that building codes have improved, several factors mean even relatively new homes might benefit from insulation upgrades:
Codes represent minimums, not optimal: Building codes specify minimum requirements to pass inspection. They don't necessarily represent the most energy-efficient or cost-effective insulation levels for long-term savings.
Quality varies wildly: Code says "R-38 minimum," but:
- Was it actually installed at R-38, or does it just pass visual inspection?
- Was it installed properly, or are there gaps and compressions?
- Has it settled since installation?
Codes change: What was code in 2010 is different from code in 2025. A home built 15 years ago met code then but might be under-insulated by today's standards.
Builders cut corners: Not all builders, but some prioritize passing inspection over maximizing performance. Insulation is invisible once drywall goes up, making it tempting to cut costs.
The Cost of This Myth
Homeowners with newer homes assume they're fine and never check, potentially missing:
- Inadequate insulation that barely meets code
- Poor installation quality
- Settling that's reduced R-value
- Opportunities to upgrade from minimum code to optimal performance
The Fix
Even if your home is only 5-10 years old, get a professional assessment. We regularly find newer homes with:
- Stated R-38 attic insulation that measures R-28 due to gaps and settling
- Improperly installed batts with significant gaps
- Insufficient air sealing
- Opportunities to upgrade from code-minimum to optimal levels
An assessment costs nothing and might reveal opportunities to significantly improve comfort and efficiency.
Bonus Myth: "Insulation Lasts Forever"
Quick bonus myth-busting: insulation doesn't last forever. While quality insulation can perform well for decades, several factors compromise it over time:
- Moisture damage: Water leaks reduce effectiveness and can lead to mold
- Pest infestation: Rodents nest in insulation and use it as a bathroom
- Settling: Especially with loose-fill insulation
- Compression: Heavy storage or foot traffic compacts insulation
- Age-related degradation: Some materials break down over very long periods
Inspect your insulation every 5-10 years, especially after roof leaks, pest problems, or severe weather. What was adequate 20 years ago might need refreshing today.
The Bottom Line: Facts Over Fiction
Insulation myths cost homeowners thousands of dollars through:
- Wrong materials for their climate
- Over-investing in diminishing-return upgrades
- Under-investing because they believe myths about their current insulation
- Ignoring critical air sealing while focusing only on R-value
The truth? Proper insulation is a comprehensive strategy involving:
- Right R-value for your climate (R-49 for NC)
- Appropriate material for your application
- Professional installation for optimal performance
- Air sealing concurrent with insulation
- Periodic inspection and maintenance
Get the Truth About Your Home's Insulation
At 4 Seasons Insulation, we help homeowners in Greensboro, Winston-Salem, and High Point cut through the myths and get honest assessments of their insulation needs.
We'll tell you:
- What you actually have (not what you assume)
- What you actually need (not what maximizes our profit)
- What improvements deliver the best ROI
- Which myths might be costing YOU money
Ready to get the truth about your home's insulation? Contact us for a free, no-pressure assessment. We'll bust the myths specific to your home and recommend solutions based on facts, not fiction.
Because when it comes to your comfort and energy bills, the truth will save you money.
