Masonry Magazine August 1988 Page. 21
TABLE 2
Permeance and Permeability of Materials to Water Vapor
Materials | Thickness (In.) | Resistance (Rep)
------- | -------- | --------
Materials Used in Construction
Concrete (1:2:4 Mix) | 1 | 0.31
Brick Masonry | 4 | 1.3
Concrete Block (Cored, Limestone Aggregate) | 8 | 0.4
Tile Masonry, Glazed | 4 | 8.3
Asbestos Cement Board | 0.12 | 0.1-0.20
With Oil Base Finishes | 0.12 | 2-30
Plaster on Metal Lath | 0.75 | 0.067
Plaster on Wood Lath | | 0.0919
Plaster on Plain Gypsum Lath (With Studs) | | 0.050
Gypsum Wall Board (Plain) | 0.375 | 0.020
Gypsum Sheathing (Asphalt Impreg.) | 1 | 0.050
Structural Insulating Brard (Sheathing Qual.) | 1 | 0.05-0.02
Hardboard (Standard) | 0.5 | 0.02-0.011
Hardboard (Tempered) | 0.125 | 0.091
Wood, Sugar Pine | 0.125 |
Plywood (Douglas Fir, Exterior Glue) | 1 | 0.2
Plywood (Douglas Fir, Interior Glue) | 0.25 | 2.5-0.19%
Acrylic, Glass Fiber Reinforced Sheet | 0 | 0.53
Polyester, Glass Fiber Reinforced Sheet | 0.048 | 8.30
Thermal Insulations
Air (Still) | 1 | 200
Cellular Glass | 1 | 0.0083
Corkboard | 1 | d
Mineral Wool (Unprotected) | 1 | 0.48-0.38
Expanded Polyurethane (R-11 Blown) Board Stock | 1 | 0.0086
Expanded Polystyrene-Extruded | 1 | 2.5-0.620
Expanded Polystyrene-Bead | 1 | 0.83
Phenolic Foam (Covering Removed) | 1 | 0.5-0.170
Unicellular Synthetic Flexible Rubber Foam | 1 | 0.038
Plastic and Metal Foils and Filma
Aluminum Foil | 0.00035 | 5.0-6.70
Polyethylene | 0.002 | 20
Polyethylene | 0.006 | 6.3
Polyethylene | 0.010 | 17
Polyvinylchloride, Unplasticized | 0.002 | 33
Polyvinylchloride, Plasticized | 0.004 | 1.5
Polyester | 0.001 | 1.3-0.72
Polyester | 0.0032 | 1.4
Polyester | 0.0076 | 4.3
Cellulose Acetate | 0.01 | 12.5
Cellulose Acetate | 0.125 | 0.2
Materials | Weighth | Resistance (Rep)
------- | -------- | --------
Building Paper, Felts, Roofing Papersd
Duplex Sheet, Asphalt Laminated, Aluminum Foil - One Side | 8.6 | 3.1
Saturated and Coated Roll Roofing | 65 | 500
Kraft Paper and Asphalt Laminated, Reinforced 50-120-30 | 6.8 | 20
Blanket Thermal Insulation Backup Paper, Asphalt Coated | 6.2 | 3.3
Asphalt Saturated and Coated Vapor Retarder Paper | 8.6 | 2.5
Asphalt - Saturated but Not Coated Sheathing Paper | 4.4 | 5.0-3.3
15-16 Asphalt Felt | 14 | 0.3
15-16 Tar Felt | 14 | 1.0
Single Kraft, Double | 3.2 | 0.25