1. 6. WOOD LIGHT FRAME CONSTRUCTION

3. LIGHT WOOD FRAMING Advantages Flexible Easily constructed Economical
Disadvantages
Burns rapidly,
Decays if exposed to moisture
Changes volume with moisture changes
Framing unattractive (must be covered)

4. 6.1 WOOD LIGHT FRAME CONSTRUCTION - AN OVERVIEW
6.2 INTRODUCTION TO BALLOON FRAME AND PLATFORM FRAME
6.3 BALLOON FRAME
6.4 PLATFORM FRAME - ADVANTAGES AND DISADVANTAGES
6.5 EIGHT STEPS FOR BUILDING A LIGHT WOOD FRAME STRUCTURE

5. 6.2 INTRODUCTION TO BALLOON FRAME AND PLATFORM FRAME
Advantages: Flexible - Any shape can be constructed - Has evolved over 150 years - Easily and swiftly constructed by hands, with a minimum amount of tools
Deficiencies: Rapid burning during fire - Decays fast exposed to dampness - Expands and contacts significantly, causing cracking of plaster, sticking of doors, buckling of floors, etc. - Can be controlled
Two types: Balloon frame and Platform frame - Advantages and disadvantages
Conventional Platform Frame - Built with 2” (nominal size) members - connected with nails - Lumber aligned horizontally and vertically and covered with sheathing - Floors and walls constructed - Sloping roof built with header at lower edge and ridge boards at the the top

6. 6.3 BALLOON FRAME
In 1865, G.E. Woodward wrote ”A man and a boy can now attain the same results, with the ease, that twenty men could on an old-fashioned frame… the balloon frame can be put up for forty percent less money than the mortise and tenon frame”
Framed solely with slender, closely spaced wooden members - Joist for floors, studs for walls, and rafters for sloping roofs - Heavy beams were eliminated
The full length studs ran continuously for two stories from foundation to roof; hence not efficient for erection - The tall hollow spaces, in between the studs, acted as multiple chimneys, spreading the fire very rapidly to upper floors

7. 6.3 Balloon Framing (Cont’d)
“All” Light Wood Framing
Full Length Studs
Cost - Less than Timber
Disadvantages
Full length studs difficult to handle
Hang 2nd floor platform
No firestop

8. 6.4 PLATFORM FRAME WITH ADVANTAGES AND DISADVANTAGES
Evolved from balloon frame after many modifications
Accepted now as the universal standard for wood light frame construction
Complex in details, but simple in concept
A floor platform is built, made up of either of a concrete slab on-ground or with masonry/concrete footings - Wood load-bearing walls are erected upon this floor/footings - A second floor wood platform is built on these walls - Then a second set of walls is built on this platform - The attic and roof are then built upon the second set of walls - Many variations are possible; one or two stories tall, several types of roof (with or without attic) can be built
Advantages: Uses short, easily handled lengths of lumber for the vertical framing - Vertical hollow spaces are automatically fire-stopped at each floor level

9. 6.4 Platform Frame (cont’d)
Advantages
Short, easily handled lumber
Made entirely of 2” lumber
Automatic fire stop
Working platforms
Nail Connections
Disadvantage -Vertical shrinkage

10. 6.4 PLATFORM FRAME ….. (Cont’d)
Disadvantages: Each floor constitutes of a thick layer of wood, whose grain runs horizontally - Leads to relatively large amount of vertical shrinkage in the frame, as moisture dries from the wood - Can lead to distress in exterior/interior finish surfaces
A conventional frame built entirely of 2” members (11/2 ” actual), with all connections made with nails
Number of framing lumber are aligned parallel to one another, and nailed to cross pieces; then covered with a sheathing (made up of a facing layer of boards, or panels) that join and stabilize the pieces into a single structural unit - In a wall structure, the vertical parallel pieces are called the studs, the cross pieces at the bottom are the sole plates, and the cross pieces on top are called the top plates
In a floor, the parallel pieces are floor joists, and the cross pieces at the ends are called headers, rim joists, or band joists. Sheathing on floor is called sub-floor
In a sloping roof, the rafters are headed off by the top plates at the lower edges of the roof and by the ridge board at the peak

11. 6.5 Building Sequence Plan / Design the Facility
Establish Use, Owner Preference, Budget
Consider Codes, Zoning & other Legal Requirements
Graphically Communicate Building Design
Foundations Design
Framing plans (identifies & locates framing members)
Architectural Floor Plans (locations, dimensions, walls, etc)
Exterior Elevations (details, openings, heights, finishes, etc.)
Interior Elevations & Sections (construction details, finishes, etc.)
Heating & AC, Plumbing, Electrical

12. 6.5 EIGHT STEPS FOR BUILDING A WOOD LIGHT FRAME STRUCTURE (Cont’d)
Step 1: Establishing the position, shape, and size of the building on site Erecting the batter boards, beyond the area to be excavated Corner stakes located with a plumb bob
Step 2: Excavation and construction of the foundation and substructure walls Excavating the foundations Form work built for walls
- Site-cast concrete foundation Slab-on-grade or other
- 4” layer of crushed stone, 3” to 4” thick concrete
- drainage for foundation
- Wall keyed to the floor slab
- Independent spread footings

16. Foundation Wall Systems
Sill Anchor
Concrete or CMU Wall
Damp-proofing
Drainage Stone under SOG
often w/ Vapor Barrier
Stone for
Drainage
Perforated Drainage Pipe
Concrete Strip Footing

17. Thickened Slab-on-Grade
Load
Stone Base
Thickened SOG

18. Damp-proofing, Protection Board, & Drainage

19. Sequenced Photos of a Home Under Construction
Foundation

20. Foundation Materials
Reinforced Concrete
Concrete Masonry Units

21. Vapor Barrier
Granular SubBase

22. Foundation Insulation
Insulate the Crawl Space
Attach to Platform or on Ground
Vapor Barrier
Insulate the Exterior of the Wall
Insulation exposed to the elements
Insulate the Interior of the Wall
Space & condensation considerations
Insulation within the Wall (CMU)

23. 6.5 EIGHT STEPS ………. (Cont’d)
- Concrete wall built
- Interior steel pipe columns
- Exterior foam insulation for frost protection
- Batt insulation over plastic moisture barrier in crawl space in basement
- Drainage for walls
Step 3: Making the ground floor platform
- Floor framing plan
- Fire place and stair case opening
- Double header and trimmer joists at floor openings
- Bridging at mid-span
- Plywood sheets laid with their length directions perpendicular to joists
- Joining details
Step 4: Framing of the ground floor walls
- Wall framing details

24. Building Sequence - Step Three Erecting the Platform Frame
Considerations
Attachment to the Foundation
Floor Framing
Sheathing

25. Attachment to the Foundation
Sill Material
Decay Resistant
Termite Shield
Sill Attachment
Anchor Bolts
Expansion Bolts
Add’l for Wind / Quake
Set to Line & Elevation

26. Floor Framing - Spacing & Splicing
Factors Influencing Joist Spacing:
Floor Loading (Minimums in Code) & Span Length
Strength of Joist Material Used
Sheathing (strength & size)
Designation - Inches “o.c.” (on center)
Typical - 16” oc (Other Typ. Options - 12” or 24”)
Splicing a) In - Line (w/ metal strap or wood)
b) Lapped

27. Floor Framing Material
(larger sizes optional)
Trusses
Wood,
Metal, or
Combination
I-Beams

28. Floor Framing Bridging & Anchorage
Material - Wood or Metal
Purpose:
Improve Rigidity
Hold Joist Straight &
Distribute Loads
Code requires for joists > 2x12
Joist Hanger
Metal - Sized to Joist
Purpose
Anchorage &
Support

29. Wall Framing Layout Framing Member Size & Spacing
Loads - Vertical & Lateral
Floor Loads, # of Stories, Roof Loads, Wind, Quake
Minimum - Code Requirements
Attachment of:
Exterior and
Interior Finishes
Opening Locations - Doors & Windows
Insulation Requirements (may elect to use ‘deeper framing to accommodate thicker insulation)

30. Framing Terminology Top Plate - Often Doubled Stud Header Sheathing
Sole Plate

31. Constructing the Wall Framing
Build on the Platform & Tilt-up or
Build in Place

32. Wall Framing

33. 6.5 EIGHT STEPS ………. (Cont’d)
Step 5: Building the upper-floor platform Details of second floor platform
- Interior stairways
Step 6: Framing of the second-story walls Reinforcing against uplift
Step 7: Framing of the attic floor and roof
- Roof framing and details
- Chimney details
- Dormer
- Hip rafter
- Roof framing
Step 8: Completing the overall building frame

34. Wall Sheathing Materials: Typically – OSB or Plywood
Insulating Sheathing - (no structural qualities)

35. Sheathing Purposes: Joins & stabilizes the structure Resists uplift
Resists wracking- Resists lateral forces
Provides surface for finish material

36. Roof Framing Built-in-Place Roof Framing Built-in-Place
Ridge Board
Rafters

37. Collar Ties

38. Lookouts
Gable Framing

39. Note Strand Orientation
Hurricane Clip

40. Roof Profiles
Flat Roof
Single Pitch

41. Roof Profiles
Gable Roof
Hip Roof
Hip
Ridge

42. Siding