Blown insulation and rolled insulation are common choices for improving energy efficiency in homes. Each type has distinct advantages and drawbacks depending on the space, climate, and retrofit goals. This article compares blown and rolled insulation, focusing on installation, performance, cost, and best-use scenarios to help homeowners make an informed decision.
What is Blown Insulation
Blown insulation is installed using a machine that blows loose-fill fibers into cavities, attics, or walls. The material can be fiberglass, cellulose, or mineral wool. Blowing creates a seamless, air-tight layer that can fill irregular spaces and around obstacles more easily than rolled batts. It is particularly effective for retrofits and hard-to-reach areas where gaps and voids are common. The installation process requires access to an electrical outlet, a blower, and safety equipment for dust control.
What is Rolled Insulation
Rolled insulation, also known as batt insulation, comes in pre-cut sheets or rolls made from fiberglass, mineral wool, or cellulose. Batts are pressed between framing members in walls, ceilings, and floors. Rolled insulation is straightforward to install in standard, uniform cavities and often does not require specialized equipment. It typically provides consistent R-values per inch and can be DIY-friendly, but gaps around wiring, pipes, or irregular shapes can reduce performance if not carefully fitted.
Key Differences
- Installation method: Blown insulation uses a blower for dense, gap-free coverage; rolled insulation is placed manually between framing members.
- Filling irregular spaces: Blown insulation excels at irregular cavities and around obstacles; rolled insulation can leave gaps in complex layouts.
- Air sealing: Blown cellulosic and fiberglass can seal small gaps when properly installed; rolled batts may require additional air sealing measures.
- R-value per inch: Rolls offer predictable R-values per inch; blown insulation can achieve higher overall density in limited spaces.
- Cost and labor: Blown systems typically have higher labor costs but can be more cost-effective for retrofits; rolled insulation is usually cheaper to purchase and install for straightforward jobs.
Pros and Cons
- Blown insulation pros: Excellent for irregular cavities and attic voids; superior air sealing; effective for retrofit projects; reduces temperature fluctuations in complex spaces.
- Blown insulation cons: Requires equipment and skilled installation; potential dust during application; higher upfront labor costs.
- Rolled insulation pros: Simple installation in standard cavities; typically lower initial cost; easy to handle and cut; DIY-friendly for small projects.
- Rolled insulation cons: Prone to gaps if not fitted well; less effective for tight air sealing; may perform poorly in irregular or obstructed spaces unless carefully installed.
Best Applications
- Attic renovations with limited access, walls with existing siding, around plumbing and electrical penetrations, and retrofits in older homes where cavities are irregular or compacted.
- New construction with standard framing, easily accessible walls, ceilings, and floors, or DIY projects where simple, uniform cavities exist.
Installation Considerations
- Ventilation and moisture: Ensure proper ventilation to prevent moisture buildup, especially in attic spaces. Some materials are more moisture tolerant than others.
- Air sealing: Regardless of insulation type, address air leaks with caulks, sealants, or house wrap to maximize energy efficiency.
- Fire safety: Use materials with appropriate fire ratings and maintain clearance around heat sources as required by code.
- Pest barriers: Consider pest control measures where attic or wall cavities are accessible to rodents or insects.
Cost and Return on Investment
- Rolled insulation generally costs less per square foot installed, while blown insulation may require professional labor and equipment charges.
- Energy savings: Both types improve thermal performance; blown insulation can deliver tighter air seals, potentially yielding higher long-term savings in retrofits.
- Long-term value: Proper installation of either type can reduce heating and cooling loads, lower utility bills, and improve home comfort and resale value.
Environmental and Safety Considerations
- Material choices: Fiberglass and mineral wool are non-combustible or fire-resistant options; cellulose often uses recycled materials but may include fire retardants.
- Occupant safety: Installation should minimize dust exposure, especially with cellulose or loose fibers; use protective gear during application.
- Disposal and sustainability: Recycled content and insulation lifespans influence environmental impact; choose materials with lower embodied energy when possible.
Choosing the Right Insulation Type
Homeowners should assess attic geometry, wall access, climate, and retrofit goals. For complex spaces or retrofit projects, blown insulation often delivers better overall performance and air sealing. For straightforward, new construction, or DIY-friendly events, rolled batts can provide reliable insulation with simpler installation. Consider a hybrid approach in some cases, using batts in accessible spaces and blown insulation in hard-to-reach areas. Always verify local building codes and obtain professional guidance when needed to maximize efficiency and safety.