1. Grimsby Secondary School
Floor Framing
Grimsby Secondary School

2. Floor Framing Design Factors affecting Design of Floor System:
Load (weight of material)
Size of members
Spacing of joists
Beams or bearing walls
Stress Design Criteria (How joists are sized for proper span)
Deflection

3. Floor frame consists of
* Girders (Beams)
* Posts or columns
* Sill plates
* Joists
* Bridging
* Subflooring

4. Floor Framing

5. GIRDERS
Larger principle beam made of steel or wood supported by posts/columns or piers which support the floor joists
Can be recessed into foundation wall
Joists will set on top of girder
Can sit on top of foundation wall
Joist will hang off side with Joist Hangers

6. JOISTS SITTING ON GIRDER

7. RECESSED GIRDER

9. JOISTS HANGING FROM GIRDER

10. GIRDER COLUMN

11. Types of Girders (Beams)
Solid lumber
Glue-laminated (GluLam)
Composite beams
Parallam (PSL)
Micro-Lam (LVL)
Steel I-Beams

12. LVL - Laminate Veneer Lumber

13. PSL - Parallel Strand Lumber

14. Steel I-Beam Girder

15. Sills Often called Sill plates or Mudsills
Provide bearing for floor joists
Sill is attached with anchor bolts.
Spacing of bolts is determined by OBC
Ontario Building Code

16. SILL PLACEMENT

17. SILL IS FLUSH WITH GIRDER

18. FLOOR JOISTS
Series of parallel support beams which support floor loads and
which are supported by Girders, or bearing walls.
Types
Solid Dimensional lumber (2x __)
Wood I-beams
Open Web Floor Truss
Steel Joists
Structural Insulated Panels (SIP)

19. DIMENSIONAL LUMBER

20. DIMENSIONAL LUMBER

21. CANTILEVERED JOISTS

22. WOOD I-BEAMS Structural, load-carrying I-joists used in
residential and light commercial construction.
Composition
The flange material for I-joists is typically
dimension lumber or laminated veneer
lumber (LVL)
The web is plywood or OSB.
The "I" configuration provides high
bending strength and stiffness
characteristics.

23. WOOD I-JOISTS

24. STEEL FLOOR JOISTS

25. Open Web Joists

26. FLOOR JOIST LAYOUT

27. FLOOR JOIST LAYOUT

28. FLOOR JOIST LAYOUT

29. RIM JOIST

30. Bridging Dimensional Lumber
Joists have a tendency to sway and deflect over long
spans
Bridging stiffens flooring
Types:
Solid Horizontal bridging
Cross bridging
Span greater than 10' have at least 1 row
Span greater than 14-16' have 2 rows of bridging,
5-8 feet apart

31. CROSS BRIDGING

32. SUBFLOORING

33. Thanks for watching