Design Loads | Raised Floor Living | Southern Pine Council™

Raised Floor Living by Southern Pine Council

Search:

Building Pro Locator
Top 10 Benefits
Key Elements
The Advantages
Wood Products
Construction Process
Span Tables
Construction Details
Construction Images
Special Topics
Case Studies
Green Building
Resources

Design Loads

All elements of a raised floor system must be properly sized to support the design loads. See Table 8, Typical Building Loads.

Continuous Load Path
A continuous load path must be provided to transfer all lateral and vertical loads from the roof, wall, and floor systems to the foundation. A load path can be thought of as a "chain" running through the building. Because all applied loads must be transferred to the foundation, the load path chain must connect to the foundation. To be effective, each "link" in the chain must be strong enough to transfer loads without breaking. A continuous load path is especially important in areas subject to high winds and/or seismic forces.

Figure 8: Wind Loading

Wind and Seismic Considerations
Construction in areas subject to high-wind and earthquake forces can pose unique problems to the designer and builder. Refer to Figure 8, Wind Loading.

The ANSI/AF&PA Wood Frame Construction Manual for One- and Two-Family Dwellings (WFCM) provides engineered and prescriptive design requirements for wood-frame construction in areas subject to 85-150 mph wind speeds (3-second gusts) and seismic design categories A-D. Click here to obtain the WFCM.

Where wind speeds are less than 110 miles per hour, construction should be in accordance with the International Residential Code. In regions where wind speeds equal or exceed 110 miles per hour, raised floor systems should be designed and constructed in accordance with the WFCM.

Table 8 Typical Building Loads
Typical Occupancy Live Loads
WEIGHTS IN POUNDS PER SQUARE FOOT (psf)
40	psf	Residential — living
30	psf	Residential — sleeping
10	psf	Residential — attic without storage
Typical Dead Loads
WEIGHTS IN POUNDS PER CUBIC FOOT (pcf)
130	pcf	clay brick masonry
144	pcf	plain concrete
150	pcf	reinforced concrete
WEIGHTS IN POUNDS PER SQUARE FOOT (psf)
Ceilings
0.55	psf	gypsum board (per 1/8 inch)
Coverings Roof / Wall
0.40	psf	wood structural panel (per 1/8 inch)
2	psf	asphalt tile
16	psf	cement tile
3	psf	wood shingles
Floors & Floor Finishes
16	psf	ceramic tile
4	psf	wood flooring, 7/8 inch
Framing
11	psf	exterior stud walls — 2x4@16", 5/8" gypsum board, insulated, 7/16" wood structural panel
12	psf	exterior stud walls — 2x6@16", 5/8" gypsum board, insulated, 7/16" wood structural panel
48	psf	exterior stud walls with brick veneer
8	psf	interior wood studs with 1/2" gypsum board each side
10	psf	light-frame wood floor assemblies
15	psf	light-frame wood roof / ceiling assemblies
8	psf	windows, glass, frame and sash
Concrete/Masonry
80	psf	6"-thick concrete walls
55	psf	8"-thick concrete block walls
80	psf	clay brick masonry walls

Source: Standard Building Code, 1997 Edition, Table 1604.1 Appendix A.