A rating system known as the R-value metric helps differentiate which materials would work best in a particular situation.
The R-value is simple to understand; the higher the number assigned, the more effective the material is in keeping a home warm in the winter and cool in the summer.
Metrics used to determine the R-value include:
Specifically, the R-value is a rating of the ability for heat to transfer from one side of the material to the other side.
Types of home insulation
Batts and Blankets
The most common types of insulation are batts and blankets.
Fiberglass batts and blankets
Comes in easy to use rolls
Perfect for DIY projects
Common…easy to find
Comes in standard thicknesses and widths
Are used between joists, studs, and rafters
Some kinds come with stapling flanges to make installation easier
Needs to be carefully cut around pipes, electrical outlets, wires, etc. making installation tedious
Loses effectiveness if it gets compressed (as much as 50%)
Can be itchy to handle – need to wear long sleeves and gloves to protect your skin
Also need to use safety glasses and mask to avoid contact with glass fibers that are within the material
Made with phenol formaldehyde – a material which has been linked with cancer, however, it’s currently being phased out from use as a binder.
Floors, walls, and ceilings
Rockwool Batts and Blankets
Better fire resistance than fiberglass
Doesn’t require staples – springs into shape making installation faster than fiberglass
Doesn’t itch like fiberglass can
Retains moisture which can lead to mold growth if it gets damp
Difficult to find
As much as 90 percent commercial recycled material, some of which may include the carcinogen material crystalline silica. Inhaled rockwood fibers, however, have not been shown to cause lung cancer.
Floors, walls, and ceilings
Cotton Batts (also known as “Blue Jeans”)
Available in easy to use rolls
Easy to cut to fit around pipes, wires, etc.
Made with at a minimum of 85% recycled fiber
Includes a borate fire retardant which can also deter some insects
Pricier than other options (15 to 20 percent more than fiberglass)
Hard to find
Made of fluffy fiber strands that are blown into walls and attics, filling up nooks and crannies better than rolled insulation.
Lightweight, making it a good option for attics with ½ inch drywall ceilings and framing that’s set every two feet.
Uses up to 60% recycled material
The fluffy nature of the material can drop the effectiveness of its insulating properties if it’s not also topped by other types of insulation such as blanket or higher density loose-fill material.
Works well at all temperatures
The colder it gets, the more effectively it works
Consists of 85% post-consumer paper that’s been recycled and 15% fire retardant usually consists of a borate compound – a pest deterrent.
It’s heavy, so it doesn’t work in attics as the drywall ceilings must be at least ⅝ inch thick or framed every 16 inches.
Can settle over time by as much as 20% which reduces its effectiveness
Creates a lot of dust, which is more of a nuisance than a problem because the fibers are too large to get stuck in the lungs
Used in wall cavities, unfinished attic flooring and other areas that are hard to reach with other insulation types
Structural Insulated Panels
Known in the industry as (SIPs), structured insulated panels are great at saving energy (12% to 14%) but they’re more expensive than other options.
Usually, they can be purchased in sheets that are 4×8 feet, but can also be found in larger sizes that are mainly used in new construction.
Works well if you’re adding (or replacing) siding, roofing or building an addition as they cover a large span at once. In some cases you can find SIPs with tongue-in-groove construction (to ensure a tight fit).
They’re also perfect for crawl space walls and basements.
Available in two versions; Expanded (EPS) and Extruded (XPS).
Easy to install
Found in blue or pink color
Better moisture barrier than EPS
Easy to install
Has to be cut to fit around wires, pipes, electrical boxes, etc., leaving gaps that should be filled with foam
Cannot nail anything to it – not structural
Insects and other pests can easily tunnel through it
Restricted airflow might require changes to ventilation for building code and safety requirements
Toxic smoke when panels are burned
Can be recycled, however, it’s uncommon
New floors, roofs, walls and ceilings
Thin (½ to 2 inches) yet high R-value
Usually comes with a foil facing that acts as a moisture barrier
Shouldn’t use where an interior moisture barrier has already been installed
Toxic smoke from burning panels
New roofs, floors, walls and ceilings
More expensive than batt insulation, however also comes with higher R-values. It can also act as a caulking because it forms an air barrier.
It is applied as a liquid and expands to fill empty spaces, stopping leaks in tight places.
Foam is sprayed, then once dry the excess is cut away leaving the surface flat and even.
Open-Cell Polyurethane Spray Foam
Stops air movement entirely
Water vapor can still pass through which could lead to mold if a moisture barrier isn’t used
For large jobs, the product should be professionally installed
Petroleum or plant-based plastic chemicals release VOCs when applied, which can lead to asthma or other health issues while the product is curing
Ceilings, walls and floors
Closed-Cell Polyurethane Spray Foam
Stops both air and moisture
Requires installation by a professional
Blowing agents are used that can contribute to climate change
Can release VOCs into the air leading to health complications
Ceilings, floors and walls