Insulation Types

Most of the insulation types that are available for installation or that you may find in your house are described here by name, R-value, strengths, and weaknesses. The list that follows is divided into the following categories:
Batt or Roll Insulation
Loose Fill or Blown Insulation
Rigid Board Insulation
Spray Applied Insulation
Poured-in or Injected Insulation
Radiant Barriers
Combination Insulation Systems and Structural Insulation Systems

Insulation Guide - Think carefully about the location you want to insulate and decide what your main goal is.  Are you trying to seal air leaks, add R-value, or reflect radiant heat?   Will the insulation be  susceptible to moisture, sunlight, insects or rodents?  Is there a specific problem you are trying to solve like condensation, mold, pipe freeze-ups or ice dams?  With these factors in mind look for the best insulation type for your situation.


Batt or Roll Insulation

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Common Name(s): Fiberglass,  fiberglass batts, batts, "the pink stuff"
R-value per Inch: around 3.2
Strengths or Best Use: low cost, readily available at local stores, easy DIY installation, there is little left unknown about this product- time tested, can handle small amounts of moisture, naturally fire resistant (needs no additional chemicals), use in standard framing spacing and wide cavities, some brands have high recycled content
Weaknesses: not very air tight, subject to air movement around and through the batts, low r-value per inch in narrow cavities, fibers can lead to poor indoor air quality (rare), brands containing formaldehyde off gas over time, itches like crazy during install, nesting material for rodents

Common Name(s):  High density fiberglass
R-value per Inch: 3.6 - 4
Strengths or Best Use: easy DIY installation, not damaged by moderate moisture contact, naturally fire resistant (needs no additional chemicals), moderate availability
Weaknesses: not very air tight, subject to air movement around the batts, low r-value per inch in narrow cavities, fibers can lead to poor indoor air quality (rare), itches like crazy during install

Common Name(s): Recycled denim, blue jean insulation, recycled cotton
R-value per Inch: 3.4 - 3.8
Strengths or Best Use: high recycled content, DIY installation, not itchy during install, good sound deadening
Weaknesses: expensive, not very air tight, subject to air movement around and through the batts, low r-value per inch in narrow cavities, will absorb moisture and suffer damage if wet, not available everywhere, nesting material for rodents, batts are not sized for standard construction and are difficult to cut

Common Name(s): Cotton batts, cotton insulation
R-value per Inch: 3.4 - 3.8
Strengths or Best Use: made from natural fibers, easy DIY installation, not itchy during install, can be installed at any temperature
Weaknesses: not very air tight, subject to air movement around and through the batts, low r-value per inch in narrow cavities, will absorb moisture and suffer damage if wet, nesting material for rodents

Common Name(s): Sheep's wool batts, sheep's wool
R-value per Inch:  about 3.5
Strengths or Best Use: made from natural fibers, easy DIY installation, not itchy during install
Weaknesses: not very air tight, subject to air movement around and through the batts, 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, subject to moth damage if not properly treated

Common Name(s): Mineral wool batts, mineral wool, rock wool, slag wool
R-value per Inch:  about 3.7
Strengths or Best Use: high recycled content, easy DIY installation, naturally fire resistant and can be used in close contact with stoves and chimneys, not damaged by moderate moisture contact
Weaknesses: not very air tight, subject to air movement around the batts, not widely available, fibers can cause indoor air quality problems (rare), itchy to install

Loose Fill or Blown Insulation

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Common Name(s): Cellulose, recycled paper insulation, newsprint insulation
R-value per Inch: about 3.5
Strengths or Best Use: low cost, high recycled content, DIY installation with rental machine, covers non uniform surfaces, good for attics with lots of cavity space, widely available, good sound deadening
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, permanently damaged if it gets wet, does not dry quickly, metal corrosion problems have been attributed to boric acid (fire resistant chemicals) leaching out of wet cellulose  

Common Name(s): Fiberglass, blown in fiberglass, blown in blankets
R-value per Inch: 2.8 - 3
Strengths or Best Use: low cost, DIY installation with rental machine, naturally fire resistant (needs no additional chemicals), not damaged by moderate moisture contact, covers non uniform surfaces, good for attics with lots of cavity space, widely available, some brands have high recycled content
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, brands containing formaldehyde off gas over time 

Common Name(s): Cotton, blown in cotton, blown in blankets
R-value per Inch: about 3
Strengths or Best Use: made from natural fibers, DIY installation with rental machine, covers non uniform surfaces, good for attics with lots of cavity space, widely available 
Weaknesses: not very air tight, air can flow through the insulation especially when coverage is light, good nesting material for rodents, permanently damaged if it gets wet, does not dry quickly

Common Name(s): Blown in batts, BIBs, blown fiber with binder
R-value per Inch: 3.5 - 4
Strengths or Best Use: good for wall installations except locations susceptible to moisture, readily available, minimal trim waste, good sound deadening, moderate airtightness
Weaknesses: not DIY friendly, 

Common Name(s): Mineral wool, rock wool, slag wool
R-value per Inch: about 2.8
Strengths or Best Use: high recycled content, naturally fire resistant and can be used in close contact with stoves and chimneys, not damaged by moderate moisture contact 
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

Common Name(s): Vermiculite
R-value per Inch: about 2
Strengths or Best Use: naturally fire resistant and can be used in close contact with stoves and chimneys, not damaged by moderate moisture contact, still used for insulating concrete block 
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 

Common Name(s): Perlite
R-value per Inch: 2.5 - 3
Strengths or Best Use: naturally fire resistant and can be used in close contact with stoves and chimneys, not damaged by moderate moisture contact, still used for insulating concrete block
Weaknesses: not very air tight, air can flow through the insulation especially when coverage is light, not available everywhere, not used much for home insulation anymore but it may be found in older homes 


Rigid Board Insulation

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Common Name(s): Polyisocyanurate, polyiso board
R-value per Inch: 6 - 7
Strengths or Best Use: high R-value, readily available at local stores, easy DIY installation, can be airtight if sealed/taped at the seams, good for narrow spaces that still need high R-value, air can go around but not through this insulation
Weaknesses: Expensive, R-value diminishes slightly over time especially if the foil face is removed, will absorb moisture if wet, degrades in sunlight

Common Name(s): Expanded polystyrene, EPS, bead board, polystyrene bead board,
R-value per Inch: 4
Strengths or Best Use: readily available at local stores, easy DIY installation, can be airtight if sealed/taped at the seams, air can go around but not through this insulation, used for foundation insulation and under concrete slabs
Weaknesses: Will absorb moisture if wet, degrades in sunlight, not very fire resistant

Common Name(s): Extruded polystyrene, XPS, blue board, pink board
R-value per Inch: 5
Strengths or Best Use: readily available at local stores, easy DIY installation, can be airtight if sealed/taped at the seams, air can go around but not through this insulation, used for foundation insulation and under concrete slabs
Weaknesses: degrades in sunlight, some ants will burrow and nest in XPS, not very fire resistant

Common Name(s): Rigid fiberglass
R-value per Inch: 4.4
Strengths or Best Use: easy DIY installation, air can go around but not through this insulation, used for roof  insulation (commercial) and foundation insulation, used in narrow cavities, not susceptible to moisture damage, naturally fire resistant (needs no additional chemicals)
Weaknesses: expensive, not available everywhere

Common Name(s): Phenolic foam boards
R-value per Inch: 4.8
Strengths or Best Use: used for roof  insulation (commercial) in the 1980's because it was reasonably priced for a high R-value
Weaknesses: when wet it leached an acid that was corrosive to metal roof decking, no longer distributed


Spray Applied Insulation

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Common Name(s): Open-cell polyurethane foam, open-cell, soft foam, half-pound foam
R-value per Inch: 3.5 - 4
Strengths or Best Use: air tight installation, good for high efficiency homes and saving energy, good for whole house installations except locations susceptible to moisture, readily available
Weaknesses: more expensive than batts or cellulose, 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, subject to minimum and maximum temperature restrictions during installation

Common Name(s): Closed-cell polyurethane foam, closed-cell, hard foam, two-pound foam
R-value per Inch: 5 - 6.8
Strengths or Best Use: air tight installation, good for high efficiency homes and saving energy, good for whole house installations especially locations with narrow cavities, readily available, increases structural integrity wherever applied, moisture tolerant, will not absorb moisture, minimal trim waste in standard framing sizes
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

Common Name(s): Kit foam, can foam, DIY foam
R-value per Inch: 5 - 6
Strengths or Best Use: can be used to air seal large areas or to fully insulate small areas, available for DIY but not necessarily user friendly- some learning curve and requires special respirator filters, available by mail order anywhere
Weaknesses: expensive especially if used for large areas, not user friendly- requires know how to both select right  product and install it properly,  subject to minimum and maximum temperature restrictions during installation

Common Name(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 
Strengths or Best Use: high recycled content, tight installation, good for high efficiency homes, good for whole house installations except locations susceptible to moisture, readily available, minimal trim waste
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

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Common Name(s): Open-cell polyurethane foam, open-cell injection foam, blown in foam
R-value per Inch:  4
Strengths or Best Use: air tight installation, good for retrofitting existing walls and cathedral ceilings, can bring older homes up to modern efficiencies
Weaknesses: expensive, will absorb moisture, not DIY friendly, not available everywhere, subject to minimum and maximum temperature restrictions during installation

Common Name(s): Closed-cell polyurethane foam, closed-cell injection foam, blown in foam
R-value per Inch: 5 - 7
Strengths or Best Use: air tight installation, great for retrofitting walls and cathedral slopes and any narrow cavities, can bring older homes up to modern efficiencies, increases structural integrity wherever applied, moisture tolerant, will not absorb moisture
Weaknesses: expensive, not DIY friendly, installer experience/training critical as improperly installed foam can damage walls with expansion pressure, subject to minimum and maximum temperature restrictions during installation, not available everywhere 

Common Name(s): Kit foam, can foam, DIY foam
R-value per Inch: 5 - 6
Strengths or Best Use: can be used to fill cavities or to fully insulate small areas, available for DIY but not necessarily user friendly- some learning curve and requires special respirator filters, available by mail order anywhere
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, 

Common Name(s): Dense pack cellulose, dense pack
R-value per Inch: 3.5 
Strengths or Best Use: high recycled content, tight installation, good for high efficiency homes, good for wall and cathedral ceiling retrofits except locations susceptible to moisture
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 

Common Name(s): Cementitious foam, foamed cement, magnesium silicate
R-value per Inch: 3.9
Strengths or Best Use: made from natural materials, tight installation, good for wall retrofits and enclosed cavities and cement block insulation, high fire resistance, not susceptible to moisture damage even though it will absorb moisture
Weaknesses: expensive, not DIY friendly, not available everywhere, friable (fragile and brittle)

Common Name(s):Phenolic foams
R-value per Inch: 4.8
Strengths or Best Use: air is the blowing agent, reasonably priced for retrofit insulation, good for wall retrofits
Weaknesses: not DIY friendly, not available everywhere, reports of shrinkage after installation

Common Name(s):Tripolymer foams, nitrogen based foams
R-value per Inch: 4.6
Strengths or Best Use: water is the blowing agent, reasonably priced for retrofit insulation, good for wall retrofits, good fire resistance, airtight installation
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

Common Name(s):Urea formaldehyde foam, UF foams
R-value per Inch: 4.6
Strengths or Best Use: reasonably priced for retrofit insulation, it was popular in the 1970's and 80's
Weaknesses: no longer distributed (as far as I know), if found in walls it disintegrates to the touch, banned after it was found to offgas harmful chemicals over time, should be removed and replaced if you find it in your home  

Radiant Barriers

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Common Name(s): Insulative paint, radiant barrier paint
R-value per Inch: unknown
Strengths or Best Use:  none
Weaknesses: radiant barriers are not well understood and little controlled research has been done on their effectiveness, paints in particular are prone to unbelievable claims such as very high R-values- in most cases these are "R-value equivalents," meaning that the radiant heat reflected is "equivalent" to the same amount of heat that would have been lost by conduction. Unfortunately, heat transfer by radiation does not have a direct conversion to transfer by conduction so these R-value equivalents are not accurate comparisons.  Insulation-Guide.com regards the claims  of radiant barrier paints as dubious and would like to see more 3rd party data that supports the claims.  

Common Name(s): Radiant barriers
R-value per Inch: unknown
Strengths or Best Use: locations prone to radiant heat loss or gain, more effective at reducing AC costs than heating costs, most effective in the attic above existing insulation, installed facing up. It also has the advantage of being easier to ship and taking up less trucking and warehouse space and not as irritating to install as fiberglass.
Weaknesses: if the barrier gets a layer of dust in it it's effectiveness is reduced, radiant barriers are not well understood and little controlled research has been done on their effectiveness

Common Name(s): Bubble wrap, reflective foil, bubble foil
R-value per Inch: unknown
Strengths or Best Use: below radiant floor tubing to direct heat towards the occupied space
Weaknesses: not really a primary insulation system by itself

Combination Insulation Systems and Structural Insulation Systems

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Common Name(s): Straw bales, straw
R-value per Inch: about 2.4
Strengths or Best Use: made from natural materials, low cost 
Weaknesses: not very air tight, subject to air movement around the bales, can't be used in narrow cavities, will absorb moisture and suffer damage if wet, not fully tested by time and ASTM, not for the average DIY project
 
Common Name(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
Strengths or Best Use: new construction, timber framed homes, high efficiency homes, air tight construction 
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 

Common Name(s):
Insulated concrete forms, ICF's
R-value per Inch: same as EPS insulation (the concrete mass is often ignored in the r-value calculation because it complicates the situation)
Strengths or Best Use: new construction, above grade walls, basements, crawlspaces, high efficiency homes, homes prone to high winds or earthquakes, ICFs are airtight and structurally strong  
Weaknesses: expensive, not for the average DIY project

Common Name(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
Strengths or Best Use: reasonable cost, good for new construction and air tight construction
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

Common Name(s): Exterior Insulation Finish system, EIFS (pronounced "e-fis"), stucco
R-value per Inch: Typically the same as XPS foam board R=5
Strengths or Best Use: reasonable cost, good for new construction and stucco finished homes, good way to add extra R-value to a wall system, reduces conduction losses through the wall framing
Weaknesses: this system had serious problems with trapped moisture in the 1980's - moisture management is now a regular consideration in EIFS designs

Common Name(s): Advanced framing techniques
R-value per Inch: depends on the combination of insulation materials used
Strengths or Best Use: a set of framing techniques designed to maximize cavity space for insulation, reduce the conduction losses through the "thermal bridges" of the framing, reduce the quantity of framing materials, and reduce air leaks between framing members
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

Common Name(s): Airtight drywall
R-value per Inch: n/a
Strengths or Best Use: a framing technique where the drywall is glued to all the framing members and to electrical boxes in order to make it a more effective block to air leaks, good for new construction and air tight construction, this method is sometimes used in conjunction with exterior foam sheathing (below)
Weaknesses: labor intensive, makes later sheetrock removal for renovations difficult

Common Name(s): Exterior foam sheathing
R-value per Inch: same as XPS (R=5) or Polyiso board (R=7) depending on what is used  
Strengths or Best Use: A framing technique where the wood sheathing (typically plywood or OSB) is replaced with  1" to 4" thick rigid foam panels or nail base panels.  The wall bays are filled with batts or cellulose.  Also used to add insulation over existing sheathing before new siding is installed.  Good for new construction and for retrofits on existing walls during siding replacement, good for reducing conductive losses through the framing     
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

Common Name(s): Double wall construction
R-value per Inch: varies depending on wall thickness and types of insulation used  
Strengths or Best Use: A framing technique where a second exterior wall is built inside the main exterior wall. the outer wall typically has a continuous air an vapor barrier, electrical penetrations remain within the inner wall. Both walls and the space between are insulated for a very high total R-value and reduced heat loss through framing members
Weaknesses: increased framing materials, increased labor, some learning curve for the DIY builder, windows and doors have to have jamb extensions to match the added wall thickness

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