As a Delaware homeowner, picking the right type of insulation for your home can be tough. With our hot, humid summers and cold, damp winters, your home needs proper insulation to stay comfortable and efficient year-round. In fact, the right insulation materials can cut your heating and cooling bills by up to 15%. That’s real energy savings!
But which type is the best one for your home? Let’s look at some of the most popular insulation options and how they compare to one another.
Why Insulation Matters
First, why do you need insulation? Insulation works by slowing heat transfer, keeping warm air in during winter and out during summer. This reduces the strain on your HVAC system, which saves you money and keeps you comfortable year-round. Some insulation options, like spray foam, also make your home structurally stronger, especially during storms. When paired with air sealing, proper insulation also helps prevent air leakage, moisture build-up, and mold issues to create a healthier indoor environment.
Our climate affects how much insulation you’ll need for your home. Our mixed humid climate puts Delaware in climate zone 4. Each climate zone needs a certain amount of insulation to meet recommended standards for thermal resistance. The colder the climate, the more insulation you’ll need. That means areas like your attic need an R-value (insulating power) of R-49 to R-60, and your walls should have at least R-13 to R-20.
Comparing Insulation Types
Now let’s check out some popular insulation materials for your home.
Spray Foam Insulation
This high-performance product is sprayed as a liquid and expands to fill every nook and cranny. It comes in two forms: open-cell and closed-cell spray foam.
Benefits
- The only option that insulates and air seals in one step.
- Has a high R-value per inch (R-6 to R-7), making it a top choice for energy efficiency.
- Adds structural strength to your home.
- Closed-cell foam acts as a vapor barrier to resist moisture.
Drawbacks
- It’s the most expensive insulation option with the biggest investment up front.
- It requires professional installation.
- It’s permanent and difficult to remove.
- Open-cell foam is not water resistant.
Best Applications
Attics, rim joists, crawl spaces, bonus rooms over garages, cathedral ceilings
Fiberglass Insulation
This classic insulation is made of glass fibers and comes as rolls/batt insulation or in a loose fill form and is a go-to for many homeowners.
Benefits
- Cost effective and widely available.
- Non-combustible and moisture resistant.
- Contains up to 60% recycled content.
- Doesn’t deteriorate over time.
Drawbacks
- Doesn’t block airflow on its own, requiring separate air sealing.
- Batts must fit properly for maximum effectiveness, making proper installation
- Performance is reduced if compressed or wet.
- Can irritate skin and lungs during installation.
Best Applications
Open wall cavities, attics with regular joist spacing, and larger areas where budget matters.
Blown-In (Loose Fill) Insulation
This type of insulation is made of loose fibers (usually cellulose or fiberglass) that are blown into place with a special machine.
Benefits
- Excellent for irregular areas and retrofitting.
- Dense packing fills all voids in enclosed walls.
- Provides some soundproofing.
- It is relatively affordable.
Drawbacks
- Requires proper equipment and installation technique.
- Not an air barrier (needs separate air sealing).
- Can settle over time if not correctly installed.
- Professional help needed for walls.
Best Applications
Attics, enclosed existing walls, and hard to reach cavities.
Mineral Wool
Mineral wool is made from molten basalt rock and a recycled steel-making byproduct called slag that’s superheated and then spun into fibers that resemble wool. It comes in both batt and loose fill form.
Benefits
- Outstanding fire retardant that slows the spread of fire.
- Excellent thermal resistance
- Superior sound insulation.
- Moisture and mold resistant.
- Contains up to 60% recycled material.
Drawbacks
- More expensive than fiberglass.
- Harder to cut and handle.
- Limited availability in some areas.
- Slow to dry if saturated.
Best Applications
Exterior walls, media rooms, basements, or any place where fire safety or sound matters.
Rigid Foam Board Insulation
Foam board is a rigid polyurethane or polystyrene insulation product that is formed into insulation sheets.
Benefits
- High R-value per inch (R-4 to R-6.5).
- Eliminates thermal bridging.
- Lightweight and cuttable.
- Moisture resistant/waterproof options.
- Pre-formed panels that are simple to handle.
Drawbacks
- Requires precise cutting and edge sealing.
- Can be labor-intensive installation.
- Needs thermal barrier coverage, such as drywall.
- More expensive than fiberglass.
- Not ideal for cavities with obstructions.
- Need additional air sealing.
Best Applications
Foundation walls, basement interiors, crawl spaces, exterior walls during re-siding, rim joists, attic hatches, and roof decks.
Factors to Consider
Let’s explore some of the deciding factors that may influence your choice of insulation.
Budget
- Cost effective: Fiberglass
- Mid-range: Mineral wool, foam board
- Premium: Spray foam
Home Areas
- Attic insulation: Blown-in, batts
- Walls: Blown-in, batts, or spray foam
- Basements/crawl spaces: Spray foam, foam board
- Cathedral ceilings: Spray foam, high-density batts
R-Value Requirements
Delaware has specific climate zone recommendations and building code requirements. Each type of insulation has a different R-value and takes varying amounts to reach the required insulation R-value. This could affect cost and installation time.
Installation Method
Some insulation materials may lend themselves to possible DIY options, such as fiberglass or mineral wool, while others require proper installation by a professional, such as spray foam. Even though it may seem tempting to DIY your insulation, it’s always wisest to trust your installation to a professional for maximum effectiveness.
Moisture Issues
Be sure to fix air leakage first, before installing insulation. For damp spaces, use closed-cell foam or foam board and consider a vapor barrier for your exterior walls.
Special Home Characteristics
- If you have a historic home: Use non-invasive blown-in insulation.
- For noise concerns: Choose fiberglass or mineral wool.
- If you have a modern home: It may already have an air barrier.
Your Home For Insulation Solutions
Choosing the right type of insulation for your Delaware home depends on your budget, your specific needs, and how it’s installed. Many homes benefit from using multiple insulation types, such as spray foam for air sealing and fiberglass insulation for bulk coverage.
At Delmarva Insulation, we’ve been serving the Mid-Atlantic region since 2002. Local homeowners and builders know they can count on our tailored insulation solutions and expertise. So, whether you’re upgrading your attic insulation or improving your walls, we can help you pick what’s best for your home.
Contact us today to learn how our experienced insulation installers can boost your Delaware home’s energy efficiency and comfort.
Works Cited
“Delaware – Humid, Temperate, Coastal.” Britannica, www.britannica.com/place/Delaware-state/Climate#:~:text=The%20climate%20of%20Delaware%20is,precipitation%20is%20nearly%2045%20inches. Accessed 28 Apr. 2025.
“Guide to Home Insulation.” Energy.gov, U.S. Department of Energy, www.energy.gov/sites/prod/files/guide_to_home_insulation.pdf#:~:text=Benefits%20of%20Insulation%20On%20average%2C,leaks%20all%20around%20your%20house. Accessed 28 Apr. 2025.
“Insulation.” Energy.gov, U.S. Department of Energy, www.energy.gov/energysaver/insulation#:~:text=Climate%20Zone%20Uninsulated%20Attic%203,R15%20CI%20Add%20R10. Accessed 28 Apr. 2025.
“Insulation Materials.” Energy.gov, U.S. Department of Energy, www.energy.gov/energysaver/insulation-materials#:~:text=Cellulose%20insulation%20is%20made%20from,The%20paper. Accessed 28 Apr. 2025.
“Types of Insulation.” Energy.gov, U.S. Department of Energy, www.energy.gov/energysaver/types-insulation#:~:text=,air%20leaks%20before%20installing%20insulation. Accessed 28 Apr. 2025.
