Building Materials Property Table
This table presents some of the key technical properties of many of the most common building materials.
The information presented has been compiled from:
- ASHRAE Fundamentals - 2001
- Moisture Control in Buildings
- CMHC
- NRC/IRC
- IEA Annex 24
- Manufacturer data
When using this information, it MUST be done in the following context:
- Some of these properties are difficult to measure and very sensitive to small changes in the material. That is why ranges are often given and any single value should be considered "representative."
- The importance of the numbers is almost always in the context of the numbers for substitute or alternative materials.
- In order to compare numbers, they must be in the same units and obtained under the same standard test conditions - a very tall order. This is the main reason that a table like this has never really been compiled before. The table and its contents will continue to be refined and gaps filled in.
- The importance of the numbers is almost always in the context of a given building assembly, for a given climate.
- There are very few if any bad building materials, from a building science perspective; bad applications, however, abound.
- The most important column in this table is likely to be the "Comments" column because it includes the experience/expertise/unique perspective of many of the leading building scientists in North America. The title of this column could be "OK - now what do these numbers REALLY mean?"
Use this table to augment the information provided in the Building Profiles and Best Practices of the Houses That Work resource. And remember, this resource attempts to supply you with the best knowledge currently available - your professional and field use of it turns it into wisdom.
This table is a work in progress - please direct questions or comments to: info@buildingscience.com.
Building Materials Property Table |
HPR= Hydrostatic Pressure Resistance (AATCC127) | SD = Smoke Development (ASTM E84) |
| AP = Air permeability (ASTM E2178-01) | WA = Water Adsorption (ASTM C209) | |
| FS = Flame Spread (ASTM E84) | ||
| MGI/IC - Mold Growth Index for Interior Coatings (ASTM D3273) MGI/I&F - Mold Growth Index for Insulation & Facings (ASTM C1338) |
| Material | Typical Relevant Dimension |
Water Vapor Permeability |
Water Absorption2 | R-Value | Other Relevant Properties | Comments | Web Link for More Information | |
|
Dry Cup |
Wet Cup |
|||||||
| Exterior Sheathings | ||||||||
| Plywood (CDX) |
3/8" |
0.75 |
3.5 |
na |
0.5 |
FS =76-200 SD =130 | At saturation, factor of 10 increase in permeability -- 14 - 20.5 perms | More Information |
| OSB |
3/8" |
0.75 |
2 |
na |
0.5 |
FS = 148 SD= 137 | At saturation, marginal increase in permeability - 2.8 - 3.4 perms | More Information |
| Fiberboard - asphalt impregnated |
7/16" |
14.5 |
15 |
2.3 - 7% |
1.2 |
FS > 75 AP=0.82 | Among the most vapor permeable of exterior sheathings | More Information More Information |
| Thin profile structural sheathing |
.078" - .137" |
0.5 - 0.6 |
0.5 - 0.6 |
na |
0.2 - 3.4 |
R-value dependent on air space; this sheathing is essentially an exterior vapor barrier | More Information | |
| Foil-faced PIR insulation |
1" |
0.01 |
0.03 |
0% |
7 |
FS = 5 SD = 165 |
Combined thermal, vapor transmission & combustion properties must be used appropriately | More Information |
| XPS rigid insulation |
1" |
1 |
1 |
0.10% |
5 |
FS = 5 SD = 165 AP=0 |
Compare/contrast moisture properties to EPS, CAREFULLY | More Information |
| XPS (skinned) |
3/8" |
0? |
0? |
1.5 |
Polypro skin enables the fan-fold but can be removed and greatly affects vapor permeability | |||
| EPS rigid insulation (Type II - 1.5 pcf density) |
1" |
3.5 |
3% |
3.7 |
FS = 20 CD = 150 - 300 |
There are lots of different grades and densities--and hence toughness--of EPS. Make sure you specify by Type (they range from Type I--1 pcf to Type IX--2 pcf) | More Information | |
| Glass mat faced gypsum board (DensGlass®) |
1/2" |
23 |
5% |
0.56 |
FS = 0 SD = 0 |
Among the most vapor permeable of exterior sheathings | More Information | |
| Wall Claddings | ||||||||
| Brick |
31/2" |
1.7 - 13.7 |
0.1 |
Properties as variable as the material but water storage capacity is always very high | More Information | |||
| Traditional stucco |
7/8" |
3.8 |
5.8 |
0.1 |
Properties as variable as the material but almost always has relatively high vapor permeability | |||
| Polymer-modified stucco | Vapor permeability is dependent on paint - with latex paint generally in the 2-3 perm range; with elastomeric paint highly variable. | |||||||
| Wood lap siding (unfinished) |
3/8" |
"35 perms" |
0.5 |
FS = 69 SD = 98 |
35 perms is an equivalent vapor permeance value. Based on both empirical tests (laboratory and test hut conditions), the value is obtained under the following conditions: a 1 Pa air pressure difference between the cladding and environment; crack width between courses of 3/1000 of an inch; and crack length of 18 inches. Note that this value is independent of finishes or coatings on the wood, unless the treatment closes the width or reduces the length of the space between courses. | |||
| Fibercement lap siding (primed all surfaces) |
5/16" |
1.5 |
FS = 0 CD = 5 |
Siding comes in different finishes, including texture and coatings (factory priming). Product must be installed over top of a weather barrier--BSC also recommends over furring strips. | More Information | |||
| Vinyl lap siding |
n/a |
"70 perms" | 70 perms is an equivalent vapor permeance value. Based on both empirical tests (laboratory and test hut conditions), the value is obtained under the following conditions: a 1 Pa air pressure difference between the cladding and environment; crack width between courses of 2 sheets of paper; and crack length of 18 inches. | More Information | ||||
| Interior Wallboards | ||||||||
| Standard paper-faced |
1/2" |
40 |
FS = 15 SD = 0 |
Both faces and core highly water vapor permeable; paper faces highly susceptible to mold and mildew growth. | ||||
| DensArmor Plus™ |
1/2" |
12 |
23 |
5% |
FS = 10 SD = 0 |
Paper facings are replaced with fiberglass mat facings for increased resistance to moisture, mold and mildew. | More Information | |
| Fiberock® |
1/2" |
|||||||
| Hardie Tilebacker Hardie Backerboard 500 |
13/32" |
2.8 |
FS = 0 SD - 5 |
More Information | ||||
| DensShield® |
1/2" |
A tilebacker board with the top face acrylic coating acting as water and moisture barrier. | More Information | |||||
| Durock® |
1/2" |
|||||||
| Non-paper faced gypsum board: Fiberock Aqua-TOUGH™ | 1/2" | 35 | .5 |
FS = 5 |
Drainage pattern is embossed on back surface of sheathing | More Information | ||
| Cavity Fill Insulations | ||||||||
| Fiberglass/Rockwool (unfaced batt) |
31/2" |
120 |
168 |
11 |
FS = 10 SD = 10 |
The thermal performance of all batt insulation depends on independent air sealing components and details. | More Information | |
| Cellulose |
31/2" |
75 |
<15% |
13 |
FS < 25 SD < 50 |
While the air tightness of cellulose insulation is significantly better than some other common cavity fill insulation, it's thermal performance still depends on independent air sealing components and details. | More Information | |
| Icynene - modified spray urethane |
31/2" |
16 |
0% |
12.6-14 |
FS < 20 SD < 400 AP = 0.008 |
While all spray foams are excellent for air sealing, they vary, often widely, in their density, R-value, blowing agent, water resistance, vapor permeability. These last two can have the greatest affect on just how you use spray foam in various building assemblies. | More Information | |
| Flooring | ||||||||
| Hardwood |
3/4" |
|||||||
| Softwood |
3/4" |
|||||||
| Glazed tile |
3/8" |
|||||||
| Synthetic carpet | ||||||||
| Organic fiber carpet | ||||||||
| Linoleum | ||||||||
| Vinyl tile | essentially vapor impermeable--not recommended with concrete floors, particularly with high w/c ratios | |||||||
| Vinyl sheet |
1/32" - 1/16" |
essentially vapor impermeable--not recommended with concrete floors, particularly with high w/c ratios | ||||||
VaporDry Cup |
Permeance
(Perms)1 Wet Cup |
Air Permeance |
||||||
| Sheet Good Building Products | ||||||||
| No. 15 asphalt-saturated felt | 6 |
31 |
0.4 |
vapor permeable at any moisture content should be compliant with ASTM D226 |
||||
| No. 30 asphalt-saturated felt |
0.19 |
should be compliant with ASTM D226 | ||||||
| Tyvek® |
58 |
0.0045 (@ wind pressure 30 mph) |
HPR=210 cm FS = 5 SD = 20 |
More Information | ||||
| Typar® |
0.013" |
14 |
|
0.0023 |
HPR=165 cm FS = 0 SD = 15 |
|||
| 60-minute roofing paper: Fortifiber Two-Ply Super Jumbo Tex | two ply |
11
|
More Information | |||||
| Polyethylene |
.004-.006 (4-6 mils) |
0.06 |
0.06 |
0? |
FS = 5-35 SD = 15-80 |
a vapor barrier appropriate only for very cold climates | ||
| MemBrain™ |
2-mil |
1 |
12+ |
FS = 75 SD = 450 |
well-suited as a vapor pressure boundary for cold and mixed climates | More Information |
||
| Coatings | ||||||||
| Vapor retarder primer |
0.25 mm |
0.5 |
|
|||||
| Latex paint (primer + sealer) |
3.5-6.1 |
~17 |
although published laboratory data (Kumaran 2002) typically gives gypsum board painted with latex paint a value of ~3 perms (dry cup), BSC has measured samples with dry cup measurements of roughly 8-10 perms (see Ueno et al. 2007) | More information |
||||
| Exterior acrylic paint | 5.5 | |||||||
| Semi-gloss vinyl acrylic enamel | 6.6 |
6.6 |
||||||
| Exterior oil-based paint (3 coats) | 0.3-1.0 |
|
||||||
| Oil paint (1 coat + primer) |
1.6 - 3 |
|
various primers plus 1 coat flat oil paint on plaster | |||||
| Elastomeric paint | substantial variability in water vapor permeability | |||||||
1 The water vapor permeability of a material is roughly inversely proportional to its thickness - doubling the thickness halves the permeability. It's more complicated for films and coatings, however, and this rule should not be applied to these materials.
2 Although manufacturers often report this property per ASTM C209 and as a per cent by weight, this only gives information about the material's POROSITY (overall quantity of water absorbed over an indefinite--long, often 24 hours-- time period) and what is much more useful is the material's water absorption coefficient, a measure of WICKING (initial rate of capillary transport). There is unfortunately NO relationship between the two, no ASTM standard for the water absorption coefficient, and few manufacturers in North America have measured or reported water absorption coefficients. When researching a building product, strongly encourage manufacturers to PROVIDE the water absorption coefficient.
