TABLE OF CONTENTS NOTES
Use the tables on pp. 490 493 to help select a roof structure assembly. See p. 385 for roof coverings. Cross-sections on each table illustrate various assemblies, with depth of assembly in inches. Columns bearing the following numbers on each table show:
Standard member sizes in inches
Dead loads in pounds per square foot
Suitable live load range in pounds per square foot
Span range in feet
Typical bay size in square feet
Suitable for inclined roofs:
Y = yes
N = no
Service plenum notes
Between structural members
Under structure
U value (without insulation)
Acoustical: Comparative resistance to sound transmission:
| Impact | E = Excellent | F = Fair |
| Airborne | G = Good | P = Poor |
Fire rating in hours
Construction type classification by code (IBC)
Total costs in $/SF of roof area
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ROOF STRUCTURE ASSEMBLIES | SIZE (INCHES) | DEAD LOAD (PSF) | LIVE LOAD (PSF) | SPAN (FEET) | BAY SIZE | SUITABLE FOR SLOPE | SERVICE PLENUM | U VALUE | ACOUSTIC | FIRE RATING (HRS) | CONST. TYPE (IBC) | COST (&/SF) | ||
| IMPACT | AIR | |||||||||||||
| A. WOOD RAFTER OR JOIST | | 2 4, 6, 8, 10 & 12 | 4 TO 8 | 30 TO 50 | TO 22 | Y | BETWEEN RATERS, ONE-WAY | .71 .51 | P | F | V | 2.25 8.50 | ||
| B. PLYW'D. JOIST | | .71 .51 | 3.25 5.00 | |||||||||||
| C. WOOD BEAM & PLANK | | PLANKS OF 2, 3, OR 4 | 5 TO 12 | 20... |
