A Practical Guide to Choosing Home Insulation
Monday, January 25th, 2016
Choosing the right insulation for your home may not be as fun as comparing paint colors or picking out your backsplash tile, but it is still important decision when building a new home or renovating an older one, especially when the temperature starts to plummet. For this reason, we put together a list of the popular home insulation options with basic information about each to help you decide what material to use when insulating your home.
Batts & Blankets
This is the most common type of insulation for both residential and commercial builds. Batts and blankets insulation comes in convenient fiberglass, rockwool, or cotton rolls that are easy to transport.
Installation is fairly easy, but the material must be cut precisely and fitted around plumbing pipes, wires, and electrical outlets. Simply stuffing it into spaces will cause it to lose its effectiveness up to 50%. If you’re not a DIY handyman, it would be best to hire a professional to carry out this project.
Fiberglass Batts & Blankets
- R-value: 3.0-4.0 per inch (R-13 for a 2-by-4-framed wall)
- Advantages: Available at your local home improvement store, fiberglass batts and blankets are designed with standard widths and thicknesses to fit between studs, joists, and rafters. Stapling flanges are found in paper and foil-faced versions to make installation easier.
- Disadvantages: You’ll need to wear protective clothing during installation because the fiberglass material can irritate your skin. Rolls of fiberglass must be cut by hand to fit spaces properly and it compresses easily, making it not as effective as other more sturdy insulation materials.
- Environmental issues: Phenol formaldehyde is often used as a binder and has been linked to cancer. However, it is being phased out. Fiberglass batts and blankets can be made of up to 60% recycled content.
- Best use: Walls, floors, and ceilings
- Cost: 30 cents per square foot
Rockwool Batts & Blankets
- R-value: 4.0-5.0 per inch (R-15 for a 2-by-4-framed wall)
- Advantages: Rockwool is more fire-resistant than fiberglass and it doesn’t irritate the skin. Rockwool can also be installed without staples because the material is more sturdy and resilient than fiberglass, springing into shape against studs and filling open spaces.
- Disadvantages: You may have to place a custom order at your local home improvement store or find an insulation distributor as this material is not widely available. Rockwool also retains moisture, so it can harbor mold if it stays damp for too long.
- Environmental issues: Rockwool contains crystalline silica, which can cause long term lung disease and/or cancer if inhaled, so it is very important to wear a face mask to ensure a safe installation. Rockwool is made predominantly of recycled pre-consumer content, up to 90%.
- Best use: Walls, floors, and ceilings
- Cost: 60 cents per square foot
Cotton (aka “Blue Jeans”) Batts & Blankets
- R-value: 3.5-4.0 per inch (R-13 for a 2-by-4-framed wall)
- Advantages: Cotton doesn’t itch and it comes in rolls that are easy to manage. The material is also easy to cut and fit around pipes and electrical wiring.
- Disadvantages: This material is not widely available and is also pricier than fiberglass or rockwool.
- Environmental issues: Cotton contains borate fire retardant, which is also beneficial for deterring insect pests. It also contains at least 85% recycled fiber and its manufacturing requires very little energy.
- Cost: 90 cents per square foot
Loose-Fill Insulation
This insulation choice is perfect for ceilings and other awkward or hard to reach spaces. Loose-fill insulation is essentially fluffy strands of fiber made of various materials (like fiberglass or cellulose) which is then blown into attics and walls with an insulation blower to eliminate cold spots. To make installation worthwhile and the outcome most effective, it is best to hire a professional to do the job.
Fiberglass Loose-Fill
- R-value: 2.2–2.7 per inch
- Advantages: Fiberglass is lightweight enough for attic applications over 1/2-inch drywall ceilings with framing every 24 inches.
- Disadvantages: Because of its low density, loose applications of fiberglass may lose up to half its effectiveness as it gets colder. To avoid this, we recommend topping fiberglass with blanket insulation or cellulose loose fill.
- Environmental issues: Fiberglass contains up to 60% recycled content.
- Cost: 30 cents per cubic foot
Cellulose Loose-Fill
- R-value: 3.2–3.8 per inch.
- Advantages: Cellulose is effective at all temperatures and performs even better as the temperatures drop.
- Disadvantages: This material is too heavy for attic installations. For ceiling installation, the ceiling must have at least 5/8-inch drywall or framing every 16 inches. Cellulose can also settle almost 20% over time, reducing its effectiveness.
- Environmental issues: Installation is quite safe as cellulose fibers are too big to lodge into the lungs; dust is only a nuisance. Cellulose is typically 85% post-consumer recycled paper and 15% fire retardant (usually a borate compound).
- Best use: Ceilings, enclosed existing wall or open new wall cavities, unfinished attic floors, other hard to reach places
- Cost: 31 cents per cubic foot
Structural Insulated Panels
Structural insulated panels (SIPs) are a versatile insulation material that is most often used during new construction or large renovations. SIPs can insulate an entire wall surface, including the framing. They have superior energy savings of 12% to 14% and some sheets have tongue-and-groove edges that provide even more energy-efficiency. However, the material is more expensive than other insulation options and when facing a living area, building codes usually require the insulation to be covered with a layer of drywall.
Polystyrene SIPs
This type of SIP comes in two versions: expanded (EPS) and extruded (XPS). EPS is the least expensive and has the lowest R-value, while XPS is stronger and blocks moisture better than EPS and is usually blue or pink in color.
- R-value: 3.8 (EPS) to 5 (XPS) per inch
- Advantages: This material is lightweight, making it easy to install.
- Disadvantages: Polystyrene must be cut to fit around pipes and other wall penetrations, which can leave gaps that need to be filled with sealing foam. It’s also not structural, so you can’t nail anything to it. Insects and other pests can tunnel through the panels, so it’s best to treat them with insecticide before installing. Because polystyrene SIPs are so air-tight, a well-built SIP structure might need fresh-air ventilation for safety and to meet building codes.
- Environmental issues: Polystyrene panels emit toxic smoke when burned, so scraps and leftovers are rarely recycled.
- Best use: New walls, ceilings, floors, and roofs
- Cost: EPS: $6 for a 1-inch-thick, 4-by-8-foot sheet; XPS: $15 for a 1-inch-thick, 4-by-8-foot sheet
Polyisocyanurate SIP
- R-value: 5.6-7.7 per inch.
- Advantages: Polyisocyanurate has the highest R-value per inch of any insulation with a thickness that ranges from 0.5 inch to 2 inches. This SIP is often faced with foil, which serves as a moisture barrier. It is also easy to install.
- Disadvantages: This high quality insulation material is expensive. Because foil faced SIPs is already a moisture barrier, it shouldn’t be used in addition to an interior moisture barrier.
- Environmental issues: Like polystyrene panels, polyisocyanurate panels emit toxic smoke when burned, so scraps and leftovers are rarely recycled.
- Best use: New walls, ceilings, floors, and roofs
- Cost: $22 for a 1-inch-thick, 4-by-8-foot. sheet
Spray Foam
Spray foam is a plastic insulation that goes on as a liquid and expands, filling all nooks and crannies and sealing and stopping any air leaks. The foam mixture is sprayed into framing cavities, which after drying, can be cut for an even surface. Spray foam insulation has higher R-values than batt insulation, but costs more. Spray foam also forms an air barrier, which eliminates caulking and other weatherproofing tasks.
Open-Cell Polyurethane Spray Foam
- R-value: 3.5 to 3.6 per inch
- Advantages: Open-cell foam prevents air circulation.
- Disadvantages: A moisture barrier is still needed as open-cell foam still allows water vapor to pass through.
- Environmental issues: This insulation contains a large amount of petroleum-based or plant-based plastic. The chemicals released during application linger while curing and can cause asthma and other serious health effects. Because of this, we recommend waiting at least 72 hours before entering the area where the insulation took place.
- Best use: Walls, floors, and ceilings
- Cost: $1 to $1.20 per square foot (R-13 for a 2-by-4-framed wall)
Closed-Cell Polyurethane Spray Foam
- R-value: 6.0 to 6.5 per inch
- Advantages: Closed-cell foam prevents air circulation and stops moisture as well.
- Disadvantages: This insulation material is relatively expensive.
- Environmental issues: Closed-cell foam uses significantly more materials than open-cell foam. It also uses blowing agents that have a high global warming potential. Health risks associated with exposure are similar to open-cell foam and the same precautions should be taken.
- Best use: Walls, floors, and ceilings
- Cost: $1.75 to $3 per square feet (R-13 for a 2-by-4-framed wall)
(Source: House Logic)
At McCamy Construction, we are a different kind of construction company. Our construction and design process is rooted in client inclusion and good communication. We’ll help you make the best choices (like choosing the right insulation) for your home and offer sound advice so you can make a decision that will best fit both your need and your budget. We hire the best subcontractors and remain on-site until the work is completed. We are also flexible enough to work with special situations, like businesses who need to stay open during a renovation. Click here to learn more about our building and design process or contact us directly for more information.
Tags: batts & blankets, cellulose insulation, fiberglass insulation, home insulation, loose-fill insulation, spray foam, structural insulated panels
Thank you so much for sharing such an extensive guide on choosing the right insulation for your home! My husband and I have noticed that the insulation in our attic is really lacking, so we have been looking at different options. It sounds like the spray foam option would be really good for our situation, since the attic is mostly lacking in insulation around the ceiling. I’ll talk to him later today about this, and see what he has to say. Thanks again!