A Homeowner's Guide to Insulation
Choosing the right insulation is crucial for your home's comfort and energy efficiency. This guide breaks down the most common types available.
What is R-Value?
R-Value measures an insulation's ability to resist heat flow. **The higher the R-value, the better its insulating performance.** Your required R-value depends on your climate zone and where you're insulating (attic, walls, etc.).
Fiberglass (Batts & Rolls)
R-Value/inch: 3.1 - 4.3
The most common and affordable type of insulation. Comes in pre-cut batts or rolls designed to fit between standard stud and joist spacing.
Pros:
- Inexpensive
- DIY-friendly
- Widely available
Cons:
- Can be an irritant
- Loses R-value if compressed
- Susceptible to moisture
Best For:
Blown-In (Fiberglass or Cellulose)
R-Value/inch: 2.2 - 3.8
Loose-fill insulation that is blown into place, making it ideal for filling enclosed existing walls, irregularly shaped areas, and topping up attic insulation.
Pros:
- Fills gaps well
- Good for existing structures
- Cellulose is eco-friendly
Cons:
- Requires machine rental
- Can settle over time
- Messy installation
Best For:
Spray Foam (Open & Closed-Cell)
R-Value/inch: 3.5 - 7.0
A chemical insulation that is sprayed in liquid form and expands to create an air-tight seal. Offers superior performance and acts as an air barrier.
Pros:
- Excellent R-value
- Creates an air seal
- Adds structural rigidity (closed-cell)
Cons:
- Expensive
- Requires professional installation
- Can shrink if installed improperly
Best For:
Rigid Foam Boards (XPS/EPS/Polyiso)
R-Value/inch: 3.6 - 6.5
Large, sturdy boards of insulation made from plastics like polystyrene or polyisocyanurate. Excellent for continuous insulation over exterior walls.
Pros:
- High R-value per inch
- Moisture resistant (XPS)
- Adds a thermal break
Cons:
- Joints must be taped
- Not for irregular spaces
- Can be damaged by UV light
Best For:
Mineral Wool (Rockwool)
R-Value/inch: 3.0 - 3.3
Made from spun rock and slag fibers. It's naturally fire-resistant and has excellent sound-dampening properties, making it great for interior walls.
Pros:
- Fire resistant
- Excellent soundproofing
- Moisture resistant
Cons:
- More expensive than fiberglass
- Heavier and denser
- Less common
Best For: