Hill House

Insulation!  I’m always trying to stay on top of what’s out there.  I stumbled across a web site that lists all different types of insulation and their pros and cons.  While it’s certainly not the bible, it gives a rough idea of what all the products can do – click here.  There are many different brands and varieties of each type, but at least this information might help you narrow down your choices quickly before you dive into specifics.

If you have the time to read it how…here is a summary of insulation:

Batt or Roll Insulation
Alias(s): Fiberglass, fiberglass batts, batts, “the pink stuff”
R-value per Inch: Approx – 3.2
Weaknesses: Not very air tight and is therefore subject to air movement around the batts. It has low r-value per inch in narrow cavities. Fibers can lead to poor indoor air quality (rare). The brands that contain formaldehyde off gas over time. It itches like crazy during install. It is nesting material for rodents.
Alias(s): High density fiberglass
R-value per inch: 3.6 – 4
Weaknesses: Not very air tight and is therefore subject to air movement around the batts, It has low r-value per inch in narrow cavities. Fibers can lead to poor in door air quality (rare), itches like crazy during install.

Alias(s): Recycled denim, blue jean insulation, recycled cotton
R-value per inch: 3.4 – 3.8
Weaknesses: Expensive. Not very air tight. Subject to air movement around and through the batts, It has low r-value per inch in narrow cavities. Will absorb moisture and suffer damage if wet. Not available everywhere. It is nesting material for rodents. Batts are not sized for standard construction and are difficult to cut.

Alias(s): Cotton batts, cotton insulation
R-value per inch: 3.4 – 3.8
Weaknesses: Not very air tight and is therefore subject to air movement around the batts. It has low r-value per inch in narrow cavities. Will absorb moisture and suffer damage if wet. It is nesting material for rodents.

Alias(s): Sheep’s wool batts, sheep’s wool
R-value per inch: Approx – 3.5
Weaknesses: Not very air tight and is therefore subject to air movement around the batts. It has low r-value per inch in narrow cavities. Will absorb moisture and suffer damage if wet. Not fully tested by time and ASTM. Not widely available. Expensive compared to other batt products. It is subject to moth damage if not properly treated.

Alias(s): Mineral wool batts, mineral wool, rock wool, slag wool
R-value per inch: Approx – 3.7
Weaknesses: Not very air tight and is therefore subject to air movement around the batts, Not widely available. Fibers can cause indoor air quality problems (rare), and it’s itchy to install.

Loose Fill or Blown Insulation
Alias(s): Cellulose, recycled paper insulation, newsprint insulation
R-value per inch: Approx – 3.5
Weaknesses: Not very air tight, air can flow through the insulation especially when coverage is light. Fibers can cause indoor air quality problems (rare). Good nesting material for rodents. Once wet it is permanently damaged. It does not dry quickly. Metal corrosion problems have been attributed to boric acid (fire resistant chemicals) leaching out of wet cellulose.
Alias(s): Fiberglass, blown in fiberglass, blown in blankets.
R-value per inch: 2.8 – 3
Weaknesses: Not very air tight. Air can flow through the insulation especially when coverage is light. Fibers can cause indoor air quality problems (rare). Itchy to install. Good nesting material for rodents. The brands that contain formaldehyde off-gas over time.

Alias(s): Cotton, blown in cotton, blown in blankets
R-value per Inch: Approx – 3
Weaknesses: Not very air tight. Air can flow through the insulation especially when coverage is light. Good nesting material for rodents. If wet it is permanently damaged. It does not dry quickly.

Alias(s): Blown in batts, BIBs, blown fiber with binder
R-value per Inch: 3.5 – 4
Weaknesses: Not DIY friendly

Alias(s): Mineral wool, rock wool, slag wool
R-value per Inch: Approx – 2.8
Weaknesses: Not very air tight. Air can flow through the insulation especially when coverage is light. Not available everywhere. Fibers can cause indoor air quality problems (rare). Itchy to install.

Alias(s): Vermiculite
R-value per Inch: Approx – 2
Weaknesses: Not very air tight. Air can flow through the insulation especially when coverage is light. Not available everywhere. Some vermiculite is contaminated with asbestos depending on where it was mined. Not used much for home insulation anymore but it may be found in older homes.
Rigid Board Insulation
Alias(s): Polyisocyanurate, polyiso board
R-value per Inch: 6 – 7
Weaknesses: Expensive, R-value diminishes slightly over time especially if the foil face is removed. It will absorb moisture if wet, degrades in sunlight.
Alias(s): Polystyrene bead board, Styrofoam
R-value per Inch: Approx – 3.5
Weaknesses: Will absorb moisture if wet. It degrades in sunlight. It is not very fire resistant.

Alias(s): Expanded polystyrene, EPS
R-value per Inch: 4
Weaknesses: Will absorb moisture if wet. It degrades in sunlight. It is not very fire resistant.

Alias(s): Extruded polystyrene, XPS, blue board, pink board
R-value per Inch: 5
Weaknesses: Degrades in sunlight. Some ants will burrow and nest in XPS. It is not very fire resistant.

Alias(s): Rigid fiberglass
R-value per Inch: 4.4
Weaknesses: Expensive. Not available everywhere.

Spray Applied Insulation
Alias(s): Open-cell polyurethane foam, open-cell, soft foam, half-pound foam
R-value per Inch: 3.5 – 4
Weaknesses: More expensive than batts or cellulose. It will absorb moisture. Not DIY friendly. Installation produces excess foam that must be trimmed and disposed of. Ongoing debate in industry about fire resistance in exposed applications. It is subject to minimum and maximum temperature restrictions during installation.
Alias(s): Closed-cell polyurethane foam, closed-cell, hard foam, two-pound foam
R-value per Inch: 5 – 6.8
Weaknesses: expensive, not DIY friendly, ongoing debate in industry about fire resistance in exposed applications, installer experience/training critical as improperly installed foam is prone to failure, subject to minimum and maximum temperature restrictions during installation.

Alias(s): Kit foam, can foam, DIY foam
R-value per Inch: 5 – 6
Weaknesses: Expensive especially if used for large areas. Not user friendly- requires know how to both select the right product and install it properly. It is subject to minimum and maximum temperature restrictions during installation.

Alias(s): Wet spray cellulose, spray cellulose, dense pack cellulose (“dense pack” is an incorrect term often used to describe wet spray cellulose, see “dense pack” under injected insulation)
R-value per Inch: 3.5
Weaknesses: Not DIY friendly. Installed wet and concerns about moisture release and mold have surfaced in the industry. Adhesion to wall surfaces can break down over time so the tight installation may not be long term.

Poured-in or Injected Insulation
Alias(s): Open-cell polyurethane foam, open-cell injection foam, blown in foam
R-value per Inch: 4
Weaknesses: Expensive. It will absorb moisture. Not DIY friendly. It is not available everywhere. It is subject to minimum and maximum temperature restrictions during installation.
Alias(s): Closed-cell polyurethane foam, closed-cell injection foam, blown in foam
R-value per Inch: 5 – 7
Weaknesses: Expensive. Not DIY friendly. Installer experience and training is critical. Improperly installed foam can damage walls with expansion pressure. It is subject to minimum and maximum temperature restrictions during installation. Not available everywhere.

Alias(s): Kit foam, can foam, DIY foam
R-value per Inch: 5 – 6
Weaknesses: Expensive especially if used for large quantities. Not user friendly- requires know how to both select right product and install it properly, DIY USERS MUST STUDY UP. Improper installations can lead to poor mixtures that don’t cure or to pushed walls, subject to minimum and maximum temperature restrictions during installation.

Alias(s): Dense pack cellulose, dense pack
R-value per Inch: 3.5
Weaknesses: Expensive. Not DIY friendly. Installer experience/training important as improper installations can push walls. Dense packing spaces under 3″ thick is very risky. Dense packing against brick can be risky because moisture can migrate through brick.

Alias(s): Cementitious foam, foamed cement, magnesium silicate
R-value per Inch: 3.9
Weaknesses: Expensive. Not DIY friendly. Not available everywhere. Friable (fragile and brittle).

Alias(s): Phenolicfoams
R-value per Inch: 4.8
Weaknesses: Not DIY friendly. Not available everywhere. There are reports of shrinkage after installation.

Alias(s): Tripolymerfoams, nitrogen based foams
R-value per Inch: 4.6
Weaknesses: Not DIY friendly. Not available everywhere. Has a reputation as being chemically related to urea formaldehyde foam which was discontinued for health reasons. Issue remains cloudy because manufacturers are not forthright about the chemistry of these foams.

Combination Insulation Systems and Structural Insulation Systems
Alias(s): Straw bales, straw
R-value per Inch: Approx – 2.4
Weaknesses: Not very air tight. It is subject to air movement around the bales. It can’t be used in narrow cavities. It will absorb moisture and suffer damage if wet. It is not fully tested by time and ASTM. Not for the average DIY project.
Alias(s): Structurally insulated panels, SIPS panels
R-value per Inch: Same as EPS (R=4) or closed-cell polyurethane foam (R=6) depending on which type of panel you get
Weaknesses: Expensive though EPS panels are less than urethane panels. Not DIY friendly. SIPS panels have had problems in the past with rot caused by condensation at panel seams and poor flashing details. Moisture management needs to be specifically considered if using SIPS.

Alias(s): Insulated concrete forms, ICF’s
R-value per Inch: Same as EPS insulation (The concrete mass is often ignored in their-value calculation because it complicates the situation).
Weaknesses: Expensive. Not for the average DIY project.

Alias(s): Flash and batt, Flash and dash.(Thin coat of spray foam for air sealing and remaining cavity filled in with less expensive insulation system).
R-value per Inch: Depends on the combination of insulation materials used
Weaknesses: The thickness of the foam coat is critical especially in colder climates and should be determined by a building science professional- if the foam is too thin it may lead to condensation inside the wall on really cold days.

Alias(s): Exterior Insulation Finish system, EIFS (pronounced “e-fis”), stucco
R-value per Inch: Typically the same as XPS foam board R=5
Weaknesses: This system had serious problems with trapped moisture in the 1980’s – moisture management is now a regular consideration in EIFS designs.

Alias(s): Advanced framing techniques
R-value per Inch: Depends on the combination of insulation materials used.
Weaknesses: Some learning curve for the DIY builder. Make sure local code officials approve the building techniques before construction. Some of the techniques require building materials not commonly found at local lumber yards.

Alias(s): Airtight drywall
R-value per Inch: n/a
Weaknesses: Labor intensive. It makes later sheetrock removal for renovations difficult.

Alias(s): Exterior foam sheathing
R-value per Inch: Same as XPS (R=5) or Polyiso board (R=7) depending on what is used.
Weaknesses: In order to maintain wall stiffness and strength metal braces must be used across the studs which is a little more labor than traditional framing, Strapping may be required outside of the foam board to make an even surface for siding. Windows and doors may have to have jamb extensions to match the added wall thickness.

Alias(s): Double wall construction
R-value per Inch: Varies depending on wall thickness and types of insulation used.
Weaknesses: Increased framing materials and increased labor. There is some learning curve for the DIY builder. Windows and doors have to have jamb extensions to match the added wall thickness.