Structural Components Chapter 5 Structural Components of the Home

Structural Loads Types of Loads Dead load Weight of building materials and permanent fixtures Live load Weight of movable objects including people and furniture Dynamic load Sudden short-term live load Ch. 5 Structural Components © Fairchild Publications, Inc.

Load-Bearing and Non-Load-Bearing Components This beam is load-bearing because it supports weight other than its own. Ch. 5 Structural Components © Fairchild Publications, Inc.

Structural Components Footings Support the structure Minimize movement Located on undisturbed soil Positioned below the frost line Ch. 5 Structural Components © Fairchild Publications, Inc.

Foundation Gravel Slab Footing Perforated pipe A bed of gravel and a drain pipe help keep water away from the joint between the footing and foundation. Ch. 5 Structural Components © Fairchild Publications, Inc.

Foundation Traditional forms have been used to pour this basement. The rough places in the walls where forms were joined are visible. Ch. 5 Structural Components © Fairchild Publications, Inc.

Foundation Stacking these interlocking foam panels allows builders to pour the concrete in the hollow spaces and leave the form to provide insulation. Ch. 5 Structural Components © Fairchild Publications, Inc.

No space beneath the structure Basement Minimum 6' height Crawl space 1' to 4' height Slab-on-grade No space beneath the structure The major difference between foundation structures is height. Ch. 5 Structural Components © Fairchild Publications, Inc.

Anchor bolts Termite shield Sill sealer Sill Ch. 5 Structural Components © Fairchild Publications, Inc.

Framing Methods Balloon Framing Stud Horizontal floor framing members are attached to the sill Vertical framing members are attached to joists Joist Studs can be multiple stories Sill Ch. 5 Structural Components © Fairchild Publications, Inc.

Platform Framing Header joist Stud Joists are attached to the sill and to edge-laid rim joists around the perimeter of the foundation. Joist Sill Ch. 5 Structural Components © Fairchild Publications, Inc.

Floor Construction 16" Most parallel structural members are placed on 16" centers. The 16" are measured from the center of the thickness of each piece of lumber. Ch. 5 Structural Components © Fairchild Publications, Inc.

Joists are aligned with the outer edge of the foundation wall. Sill Joist Header joist Stringer joist Joists are aligned with the outer edge of the foundation wall. Ch. 5 Structural Components © Fairchild Publications, Inc.

Strap bridging Solid bridging Cross bridging Three types of bridging are common between joists—all of which improve dimensional stability. Ch. 5 Structural Components © Fairchild Publications, Inc.

Web Gusset Chord Gusset detail Using floor trusses instead of joists increases the free span width. Floor trusses are usually wider than joists. Ch. 5 Structural Components © Fairchild Publications, Inc.

Floor Construction and Noise Standard floor structures readily transmit noise. Using an additional set of staggered floor joists prevents sounds from traveling through continuous framing members. A less expensive alternative is to add a ceiling below the floor joists. Insulating the floor would improve the sound transmission class even farther. Ch. 5 Structural Components © Fairchild Publications, Inc.

Double trimmer Double header Doubled framing members are used to ensure the structural integrity of an opening in the floor. Ch. 5 Structural Components © Fairchild Publications, Inc.

Wall Framing Header Studs are vertical wall framing members held in their position by a horizontal sole at the bottom and a wall header at the top. Stud Sole Ch. 5 Structural Components © Fairchild Publications, Inc.

Top plate Header The wall header is doubled to provide support for framing above and to allow the plates to be overlapped at the top to stabilize the walls. Ch. 5 Structural Components © Fairchild Publications, Inc.

Studs for inside corners Stud for outside corner Additional studs are required at inside and outside corners to ensure there is sufficient support for attaching finishing materials. Ch. 5 Structural Components © Fairchild Publications, Inc.

Additional support is provided in the wall for heavy objects such as cabinets, window treatments, and grab bars. Ch. 5 Structural Components © Fairchild Publications, Inc.

Wall Construction and Noise Standard wall construction has a low sound transmission class and easily transmits noise across the barrier. A wall structure using staggered studs prevents sounds from being carried directly through the studs. Insulating the space between the staggered studs improves the STC farther. Ch. 5 Structural Components © Fairchild Publications, Inc.

Partial walls must be at least 3' high but do not reach the ceiling. Floating wall Partial walls must be at least 3' high but do not reach the ceiling. Ch. 5 Structural Components © Fairchild Publications, Inc.

Furred walls are non-load-bearing and provide backing for finish materials and space for insulation, wiring, and mechanical system components. Ch. 5 Structural Components © Fairchild Publications, Inc.

Jack stud When there are openings in walls, support must be provided for the structure above. This is only one type of header that can be used. The opening itself must be supported as well. Header King stud Trimmer Sill Jack stud Ch. 5 Structural Components © Fairchild Publications, Inc.

Ceiling Support Joist Extra nailer Ceiling finish Wall structure An additional board is placed on top of the wall structure to provide a place for nailing finish materials when there is no other support. Ch. 5 Structural Components © Fairchild Publications, Inc.

Roofs Roof Angle Rise Span Pitch is the ratio of total rise to span expressed as a fraction. Ch. 5 Structural Components © Fairchild Publications, Inc.

Slope is the ratio of rise to run expressed as X in 12. Ch. 5 Structural Components © Fairchild Publications, Inc.

Roof Styles Flat roof Hip roof Shed roof Dutch hip roof Gable roof Mansard roof Winged gable roof Gambrel roof Jerkinhead roof Intersecting roof Ch. 5 Structural Components © Fairchild Publications, Inc.

Roof Structure Joist and rafter construction is the most common although not every roof uses all these parts. Ch. 5 Structural Components © Fairchild Publications, Inc.

Post and Beam This post and beam barn is a simplified version of the technique and uses roof trusses. Ch. 5 Structural Components © Fairchild Publications, Inc.