Design Values
Make Specifying Cypress Easier
The American Lumber Standards Committee (ALSC) has certified the first-ever set of engineering design values for cypress. The design values now are recognized in model building codes across the United States.
The certification makes it much easier for architects and builders to specify cypress for structural applications, such as exposed beams, timbers, posts, columns, headers and other large structural or accent pieces.
Grading for structural cypress will be under the auspices of the Southern Pine Inspection Bureau (SPIB) (www.spib.org). Appearance-grade cypress will continue to be governed by the rules of the National Hardwood Lumber Association (NHLA) (www.natlhardwood.org).
Summary of Allowable Base Design Values for Baldcypress Dimension Lumber
| Grade | Extreme Fiber in Bending Fb | Tension Parallel- to-Grain Ft | Compression Parallel- to-Grain Fc | Horizontal Shear Fv | Compression Perpendicular- to-Grain | Modulus of Elasticity, E |
|---|---|---|---|---|---|---|
| Select Structural | 1200 | 650 | 1200 | 160 | 615 | 1,400,000 |
| No. 1 | 1000 | 550 | 1050 | 160 | 615 | 1,400,000 |
| No. 2 | 825 | 450 | 900 | 160 | 615 | 1,300,000 |
| No. 3 | 475 | 250 | 525 | 160 | 615 | 1,200,000 |
| Construction | 925 | 500 | 1100 | 160 | 615 | 1,200,000 |
| Standard | 525 | 275 | 925 | 160 | 615 | 1,100,000 |
| Utility | 250 | 125 | 600 | 160 | 615 | 1,000,000 |
| Stud | 650 | 350 | 575 | 160 | 615 | 1,200,000 |
Design Values in Pounds Per Square Inch (psi)
Summary of Allowable Design Values for Cypress Timbers
| Grade | Extreme Fiber in Bending Fb | Tension Parallel- to-Grain Ft | Compression Parallel- to-Grain Fc | Horizontal Shear Fv | Compression Perpendicular- to-Grain | Modulus of Elasticity, E |
|---|---|---|---|---|---|---|
| Select Structural | 1150 | 750 | 1050 | 200 | 615 | 1,300,000 |
| No. 1 | 1000 | 675 | 925 | 200 | 615 | 1,300,000 |
| No. 2 | 625 | 425 | 600 | 175 | 615 | 1,000,000 |
Design Values in Pounds Per Square Inch (psi)
Comparisons Between Base Design Values for Baldcypress, Northern White Cedar, Western Cedars & Redwood Dimension Lumber
| Species & Commercial Grade | Size Classification | Bending Fb | Tension Parallel- to-Grain Ft | Compression Perpendicular- to-Grain | Compression Parallel- to-Grain Fc | Modulus of Elasticity, E | Grading Rules Agency |
|---|---|---|---|---|---|---|---|
| Baldcypress | |||||||
| Select Structural | 2″ – 4″ thick | 1200 | 650 | 615 | 1200 | 1,400,000 | SPIB |
| No. 1 | 2″ and wider | 1000 | 550 | 615 | 1050 | 1,400,000 | |
| No. 2 | 825 | 450 | 615 | 900 | 1,300,000 | ||
| No. 3 | 475 | 250 | 615 | 525 | 1,200,000 | ||
| Stud | 650 | 350 | 615 | 575 | 1,200,000 | ||
| Construction | 2″ – 4″ thick | 925 | 500 | 615 | 1100 | 1,200,000 | |
| Standard | 2″ – 4″ wide | 525 | 275 | 615 | 925 | 1,100,000 | |
| Utility | 250 | 125 | 615 | 600 | 1,000,000 | ||
| Northern White Cedar | |||||||
| Select Structural | 2″ – 4″ thick | 775 | 450 | 370 | 750 | 800,000 | NeLMA |
| No. 1 | 2″ and wider | 575 | 325 | 370 | 600 | 700,000 | |
| No. 2 | 550 | 325 | 370 | 475 | 700,000 | ||
| No. 3 | 325 | 175 | 370 | 275 | 600,000 | ||
| Stud | 425 | 250 | 370 | 300 | 600,000 | ||
| Construction | 2″ – 4″ thick | 625 | 375 | 370 | 625 | 700,000 | |
| Standard | 2″ – 4″ wide | 350 | 200 | 370 | 475 | 600,000 | |
| Utility | 175 | 100 | 370 | 325 | 600,000 | ||
| Western Cedars | |||||||
| Select Structural | 2″ – 4″ thick | 1000 | 600 | 425 | 1000 | 1,100,000 | WCLIB |
| No. 1 | 2″ and wider | 725 | 425 | 425 | 825 | 1,000,000 | WWPA |
| No. 2 | 700 | 425 | 425 | 650 | 1,000,000 | ||
| No. 3 | 400 | 250 | 425 | 375 | 900,000 | ||
| Stud | 550 | 325 | 425 | 400 | 900,000 | ||
| Construction | 2″ – 4″ thick | 800 | 475 | 425 | 850 | 900,000> | |
| Standard | 2″ – 4″ wide | 450< | 275 | 425 | 650 | 800,000 | |
| Utility | 225 | 125 | 425 | 425 | 800,000 | ||
| Redwood | |||||||
| Clear Heart Structural | 2″ – 4″ thick | 1750 | 1000 | 650 | 1850 | 1,400,000 | RIS |
| Select Structural | 2″ and wider | 1350 | 800 | 650 | 1500 | 1,400,000 | |
| Select Structural, open grain | 1100 | 625 | 425 | 1100 | 1,100,000 | ||
| No. 1 | 975 | 575 | 650 | 1200 | 1,300,000 | ||
| No. 1, open grain | 775 | 450 | 425 | 900 | 1,100,000 | ||
| No. 2 | 925 | 525 | 650 | 950 | 1,200,000 | ||
| No. 2, open grain | 725 | 425 | 425 | 700 | 1,000,000 | ||
| No. 3 | 525 | 300 | 650 | 550 | 1,100,000 | ||
| No. 3, open grain | 425 | 250 | 425 | 400 | 900,000 | ||
| Stud | 575 | 325 | 425 | 450 | 900,000 | ||
| Construction | 2″ – 4″ thick | 875 | 475 | 425 | 925 | 900,000 | |
| Standard | 2″ – 4″ wide | 450 | 275 | 425 | 725 | 900,000 | |
| Utility | 225 | 125 | 425 | 475 | 800,000/td> | ||
Design Values in Pounds Per Square Inch (psi)
