1. Wood Structures session 5 Exterior and Interior walls
Wall Framing
Exterior and Interior walls
BLDG jn/2012

2. Wall Framing Main functions of a wall system.
Transfer the structural loads of the building to the house foundation.
Resist lateral loads from earthquakes and winds.
Provide backing for interior and exterior finishes.
Control the flow of air, moisture and heat in and out of the house.
Provide spatial separation within the house.
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3. Introduction Wall system components: Studs Top and bottom plates
Lintels over openings for doors and windows
Sheathing
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4. Top plate Double top plate Lintel Lintel Lintel Cripple stud
Bottom plate
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5. Introduction
The performance of wall systems depends on design and location of walls; openings in walls; sizes; species; grades and spacing of members; thickness of sheathing; and how they are fastened together.
The Code requires the use of braced wall lines to provide lateral resistance in the structure of wood platform frame housing.
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6. Introduction Topics covered; Wall assemblage
Code requirements for lateral resistance
Space and length of braced wall lines
Other limits for use of braced wall lines
Design considerations
Studs
Plates
Openings
Connecting members
Sheathing
Notching and drilling members
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7. Wall Assemblages The wall assemblage consists of:
Bottom plate (also called sole plate) of dimension lumber laid flat and horizontal on the floor.
Bottom plate
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8. Wall Assemblages
Stud (40 x 90 or 140 mm) placed vertically between top and bottom plates.
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9. Wall Assemblages
Top plates laid horizontally on top of studs, tying them together.
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10. Wall Assemblages
Lintel of built-up, dimension lumber or engineered lumber, spanning the wall opening as a beam between studs.
Lintel
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11. Wood Structures session 5
Wall Assemblages
Jack stud (shorter than full length stud) supporting a lintel.
Lintel
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12. Wall Assemblages Rough sill, framing the bottom of window openings.
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13. Wall Assemblages
Cripple stud (shorter than full length stud) either supporting top plate above lintel or rough sill above bottom plate.
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14. Wall Assemblages
Wall sheathing of engineered wood panels on the outside of the exterior frame.
Horizontal panel alignment
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Vertical panel alignment
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15. Fastening Requirements
Studs are nailed to top and bottom plates
Studs are nailed together when doubled or at intersections or corners
Wall top plates are nailed together when doubled
Bottom plates of walls are nailed to floor joists or blocking
Lintels (often built-up lumber nailed together) are nailed to studs at each end
Lapped wall plates are nailed at wall intersections
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16. Studs
Load bearing studs support the loads from the roof and/or other floors.
They sit on the bottom wall plate and transfer loads to beams, other walls, or directly to the foundation.
The Code requires that studs used in a load bearing wall should be minimum stud grade (Class Vc) or better, dimension lumber.
Studs used in non load bearing walls can be of any grade.
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17. BLDG 1101
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18. Studs
Studs shall be continuous within a wall and may be finger jointed but not spliced.
Precut studs mm (92 ½”)
Spacing shall not exceed 600 mm.
For a house with maximum roof spans of 12 m, maximum floor spans of 6 m and studs no longer than 3 m, 40 x 90 mm studs spaced 400 mm apart can be used in the bottom storey of a 2- storey house.
For 3-storey, 40 x 140 mm should be used.
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19. Studs
The Code requires that studs be doubled on each side of openings in load bearing walls.
Corners and intersections must be framed with at least two studs to provide adequate support for fastening interior finishes, sheathing and cladding materials.
For larger openings, (3 ply or engineered lintels) a minimum of three studs is recommended on each side of the opening, two to provide adequate bearing for the lintel.
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20. Studs
For wall corners it is generally good practice to frame with three studs.
This one is better
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22. Intersecting studs
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23. Studs Plates at the top and bottom of studs are required by Code.
Plate width can not be less than the stud width.
Two top plates in load bearing walls to help distribute loads from floor joists or roof trusses to studs.
Single top plate permitted where joists are within 50 mm (2”) of studs.
In load bearing walls, the joints of the two top plates must be staggered at least the length of one stud spacing and be placed on top of studs.
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24. Wall Stud Spacing
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25. Wall Stud Spacing
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27. Walls
The bottom plate cannot project more than 1/3 the plate width over its support.
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28. Constructing the Wall Framing
Build on the Platform & Tilt-up
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29. Framing Terminology Top Plate - Often Doubled Stud Lintel Sheathing
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Sole Plate
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32. Walls / double top plate
At corners and intersections, the top plates must be lapped to enable fastening.
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34. BLDG 1101
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35. Openings Openings –windows, doors, arches
Loads over openings are transferred by lintels to supporting jack studs and adjacent full length studs which carry the loads to the floor.
Lintels are made from built up dimension lumber or engineered lumber.
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36. Lintels
Sizing Factors: Load, Span, Material, Code
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37. Lintels
Lintel Depth
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40. Openings
Single full length studs are allowed around openings in non load bearing walls or partitions.
Load bearing walls, must use lintels and double studs around openings. (Jack and King Stud).
Cripple studs between top plates and lintels in load bearing walls must be spaced according to stud spacing requirements as they carry loads from plates to lintels.
Lintels over larger openings may require more support than a jack and full length stud at each end.
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41. Loads on openings
Pay attention
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42. Lintels
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43. Lintel
1 - Jack or Trimmer stud (2) 2 – King stud (2) 3 – Cripple stud (2) 4 – Rough sill 5 – Stud – Cut-in bracing 7 – Double top plate 8 – Partition assembly Standard corner (2) bottom or sole plate Cut-in bracing kicker (2) let-in ribbon Lintel top plate
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44. Openings
In window openings the bottom is framed with a rough sill supported by cripple studs running to the bottom plate.
These cripples do not carry any significant load but are spaced according to requirements for sheathing purposes.
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45. Sizing Rough Openings
Rough stud openings (RSO) are based on the outside frame size of the door and window to be installed which is generally included in the window and door schedule in the plans.
In the case of windows the RSO is 25 mm larger than the window frame. 12 mm (1/2”) space all around the frame and opening.
This allows for the window to be shimmed, leveled, plumbed and to install foam insulation
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46. Sizing Rough Openings
For exterior door openings the RSO is obtained from the door schedule.
For interior doors the RSO is 60 mm (2 ½”) larger than the actual door size.
Eg. A door 760 x 2030 mm (2’-6” x 6’-8”) the RSO would be 820 x mm (2’-8 ½” x 6’-10 ½”)
Manufacturers will generally provide rough opening sizes for doors and windows they supply.
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47. Openings
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48. Openings
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49. Parts of the Wall Platform Construction Wood Lintel Top plate
Insulation
Stud
Jack stud
Diagonal Brace
Window frame
Rough Sill
Cripple Stud
Bottom Plate
Plywood subfloor
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Platform Construction
Fig Piedra de cantera de la isla de Portland (que inspiró el nombre de cemento portland) cerca de un cilindro del concreto moderno. (IMG12472)

50. Laying out plates
Layout top and bottom plates together on edge with the ends flush.
First step is to locate centre lines of wall openings and wall intersections.
Openings and intersections can be marked by measuring on both sides of the centre line a distance one-half the size of rough stud opening (RSO)
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52. Wall layout
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53. 9/20/2018
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54. Laying out plates The on centre, OC stud spacing is then laid out.
The edges of studs should be marked off with a square running across both plates.
Stud locations are measured from the end of the wall.
The first stud is measured back one-half the thickness of the stud to facilitate panels butt on the centre of studs.
Some times studs are lined up with floor joists to facilitate the layout of hot and cold air ducts.
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60. Wall Bracing
Chapter 9 requires the use of braced wall lines in all platform frame housing.
Braced wall lines are constructed of braced wall panels, which are wall segments stiffened to resist lateral loads from earthquakes and wind.
Braced walls must be stiffened with sheathing using either structural wood panels,( one side of the wall is sheathed) or gypsum board (both sides of the wall are sheathed)
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61. Wall Bracing
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62. Bracing
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63. Metal Bracing Detail
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64. Bracing Bracing only required when non-structural sheathing used:
Examples of non-structural sheathing are:
Tin-test fibre board
Styrofoam
Bracing not required when structural sheathing such as but not limited to plywood, or oriented strand board
Bracing can also be done with let-in wood braces
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65. Wood Bracing Detail
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67. Blocking in Walls
Blocking between studs provides additional bracing and helps studs resist buckling under load.
If walls are braced with sheathing, blocking is redundant.
Blocking, or its equivalent, is required as a fire stop in walls where stud length exceeds 3 m.
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68. Preparation for Future Attachments
The framing stage is the best time to think about simplifying future fastening requirements for:
Bathtubs
Basins or Lavatories
Baseboards
Grab Bars
Handrails etc.
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69. Blocking
Though not normally required (Check OBC) is sometimes placed in the walls to stop twisting and warping of the members
This is important when walls begin to exceed 9’-0” in height
or when renovating and installing wet wood in a dry house e.g. finishing a basement in winter, blocking provides resistance to warpage
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70. Preparation for Future Attachments
2x6 wall may be required to conceal plumbing fixtures or HVAC ducts
Floor may need to be framed specially to allow water closet to be properly located
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72. Preparation for Future Attachments
Special framing is required for tubs including access requirements for whirlpool tubs
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73. Preparation for Future Attachments
Install blocking for baseboard in corners
Optional, some carpenters like to do this because it makes nailing of baseboard easier
Increases thermo-bridging
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74. Angled Layouts Bay Window BLDG 1101 9/20/2018 Semester 2 Lesson 4
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75. Connecting Members Minimum nailing requirements for wall framing
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77. Sheathing
The requirement for braced walls in wood platform frame housing permits the use of softwood plywood, oriented strand board and gypsum board panels as sheathing materials.
Gypsum is used for interior walls.
It provides resistance to fire.
Sheathing can be placed either horizontally or vertically on walls.
Joints are located on framing members and that a minimum 3 mm gap be left between panel edges
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78. Assembling and Erecting Wall Sections
Top and bottom plates are laid out.
Studs, jacks, cripples and lintels are fastened in place.
Bottom plate is tacked to chalk line on floor and squared up using the diagonal method.
Sheathing is applied.
The wall section is then raised into place.
Once raised, the wall section is immediately braced temporarily to ensure it will not fall.
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79. Assembling and Erecting Wall Sections
Once all sections are secured, corners and walls are plumbed and bracing is adjusted accordingly.
Bottom plates are permanently fastened.
Edges of wall sections that butt together are kept flush and fastened.
The second (double) top plate is fastened to tie walls together.
It is important to ensure walls are straight and plumb.
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80. Notching and Drilling Members
Notches or holes in studs must leave a minimal two-thirds of the width undamaged in load bearing walls and a minimal 40 mm of the wall is non-load bearing.
Notches and holes in plates must leave a minimal 50 mm of the width undamaged. If this is exceeded, top plates must be reinforced.
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81. Notching of Wall Studs
According to OBC notches in studs cannot exceed these requirements
Unless suitably reinforced
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82. Notching of Wall Studs
Suitably reinforced studs
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83. Drilling of Stud
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85. Methods of Installing Joists
Semester 2 Lesson 4
Methods of Installing Joists
Rafters and ceiling joists form a triangle
Rafters are over the studs
Ceiling joists are fastened to the side of the rafters
Ceiling joists may be installed in line
Ceiling joists can also be lapped over a bearing partition similar to floor joists
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86. Semester 2 Lesson 4
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88. Cutting the Ends of Ceiling Joists
Semester 2 Lesson 4
Cutting the Ends of Ceiling Joists
Ceiling joists on exterior walls may be cut off to the roof’s slope, flush with or slightly below rafter’s top edge
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89. Stub Joists Used with low-pitch hip roofs
Semester 2 Lesson 4
Stub Joists
Used with low-pitch hip roofs
Shorter joists that run perpendicular to the normal joists
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90. Ceiling Joists
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91. Ceiling Joist Layout
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92. Framing Ceiling Joists to a Beam
Similar in purpose and design to a girder
May be of built-up, solid lumber or engineered lumber
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96. Ribbands and Strongbacks
Ribbands are 2 x 4s (38 x 89mm) installed flat on top of ceiling joists
When a 2 x 6 (38 x 140mm) is installed on edge, the ribband becomes a strongback
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