Objectives Learning Chapter 8 Building framing ! Student should become familiar with the different types of framing systems, be able to distinguish between types, and know the significant aspects of each. ! Student should know where they are used, and the advantages and disadvantages of the different types and become familiar with various structural members and terms.
" What are the important components of the framing? " What are the unique features of post-frame construction?
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Questions of the day:
1. a. b. c. d. 2. Which framing system was patented in 1953? timber balloon pole platform Describe a truss, what feature makes it an efficient structural system? 3. What is bridging in structural framing?
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TYPES OF FRAMING
! Post and Beam (timber frame) ! Stud frame (conventional)
" balloon " platform
! Post/pole frame (square post or round poles)
" intermediate poles " clear span
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Platform Framing
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! Steel framing
" post & beam " rigid
! Frameless
" curvettes " air-inflated " prefab panels
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! Rigid frame
" laminated arches " dimension lumber with plywood gussets
! Concrete and masonry
" monolithic " tilt-up panels " block
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! Effect of Sheathing and Bracing on Wood Frame Structures ! ! ! ! ! ! ! ! ! ! Type Horizontal sheathed, Unbraced Diagonal sheathed, Unbraced Horizontal sheathed, Cut-in brace Horizontal sheathed,Let-in brace 3/4" Fiberboeard 5/8" Plywood 1/4" Plywood 1/4 Plywood, glued to frame Relative Relative Relative Strength Rigidity Rank 1 1 7 7-8 4-7 3 1.4 1.6 6 4 2-4 5 3.8 3 5 9+ 4.8 2 5-7 4-6 4 8.6 14.4 1
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Learning Objectives Chapter 9 Roof Framing:
! Student should become familiar with the different types of shapes, roof learn the terms for various roof support structural members, understand why trusses are used for roof support and why trusses are efficient structural components.
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Roof support
! roof shape ! rafters ! truss types
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Roof Shapes
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! ! ! ! ! ! ! ! ! ! ! !
TRUSS SELECTION
Factor
Type Number of webs Slope Span Spacing Loading Bearing locations Purlin spacing Member size Member grade
Typical
Fink 4 to 6 3:12 to 5:12 4' to 65' 2' to 8' 2 to 45 psf Each end 24" to 40" 2" x 4" to 2" x 10" No. 2 to 2600f-2E
Range
1 to 16 1-1/2:12 to 12:12 16' to 120' 1' to 20' 8 to 60 psf Up to 12' from each end and/or midpoint 12" to 60 Up to 6" x 12" No. 3 to 3300f-2.E
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Truss anchorage
! Is toe-nailing enough? ! Uplift capacity of 16d nail into SPF top plate = 36.7 lb (Doug-fir larch is 56.7) ! At 12 psf uplift on end of 40 ft truss, 4 o.c. = 960 lb ! Nails required = 960 lb/36.7 lb/nail = 26 ! Capacity of metal framing anchor can exceed 450 lb
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Discussion Questions Chapter 8 Building Fr...