PowerPoint Presentation

1. PowerPointPresentation PublisherThe Goodheart-Willcox Co., Inc.Tinley Park, Illinois 1

2. Chapter 11 Footings, Foundations, and Concrete 2

3. Chapter 11 Overview • Introduction • Staking Out House Location • Excavation • Footing Shapes and Specifications • Foundation Walls • Concrete and Masonry Basement Walls • Beams and Girders (continued) 3

4. Chapter 11 Overview • Concrete and Masonry • Concrete Blocks • Paving 4

5. Learning Objectives • Describe the procedure for staking out a house location. • List the major considerations when designing a footing for a residential foundation. • Analyze a typical floor plan to determine the appropriate foundation. (continued) 5

6. Learning Objectives • Discuss the design considerations for wood, concrete, and masonry foundation walls. • Calculate the load to be supported by a beam. • Explain the purpose of a lintel. 6

7. Introduction • A good foundation is very important. • It requires careful planning and design. • Types of foundations: • Masonry or concrete. • All-weather wood. • Slab type. • Specialized CADD programs are available to aid the process. 7

8. Types of Foundations • Masonry foundation. 8

9. Types of Foundations • All-weather wood foundation. 9 (The Engineered Wood Association)

10. Types of Foundations • Slab foundation. 10

11. Staking Out House Location • The plot plan provides the necessary dimensions for staking out the house. • The task requires a measuring tape, contractor’s level, and possibly a transit. • Locate each corner of the house. • Use 9-12-15 unit method for square corners. • Check for accuracy by diagonal measurement. 11

12. Batter Boards • Batter boards retain location of the foundation during construction. • Locate them 4' outside the footing line. • Corner stakes located with a plumb bob. • Batter boards are attached to the stakes. • Determine a control point (corner). • Finished floor should be at least 8" above the grade. 12

13. Batter Boards • Squaring a corner using the 9-12-15 unit method. 13

14. Checking Accuracy • Measuring diagonals. 14

15. Batter Boards in Place 15

16. Excavation • Top soil should be removed and saved. • A backhoe generally used to excavate. • Excavation for footings should extend at least 6" into undisturbed earth. • The depth of excavation should also be at least 6" below frost penetration. • No backfilling under footings. • Soil tests determine soil suitability. (continued) 16

17. Excavation • Excavation must be large enough to allow space to work on the foundation. • Excavation wall should slope away from the bottom of the excavation. • Slope angle will depend on soil type. • Sandy soil requires a gentle slope. • Wall may be nearly vertical in clay. 17

18. Frost Penetration Chart • Average depth of frost penetration in inches. (US Department of Commerce Weather Bureau) 18

19. Footing Shapes • Footingsincrease supporting capacity of the foundation wall. • Most houses require footings. • Soil bearing capacity and weight of house determine the size and type of footing. • Footings are generally poured concrete. • Footing size is typically based on the foundation wall thickness. 19

20. Footing Shapes • A footing expands load bearing area. 20

21. Footing Shapes • General proportions of a footing. 21

22. Footing Specifications • Footing thickness generally equals the foundation wall thickness. • Footing width is twice the wall thickness. • Poor soil may require wider footings. • Settling occurs during construction. • Prevent uneven settling. • Check code recommendations. • Use steel reinforcing bars. 22

23. Fireplace and Chimney Footings • Fireplace and chimney footings are more massive than regular house footings. • Should be reinforced with steel. • 12 inches thick. • Extend 6 inches beyond the perimeter of the chimney. • Cast integrally with house footing. 23

24. Stepped Footings • Stepped footings are necessary when building on hilly terrain. • Steps should be placed horizontally. • Vertical step height is no more than 3/4 of the distance between the steps. • Steps should be multiples of 8 inches in masonry construction. • Use 1/2" steel bars in footings. 24

25. Stepped Footing • A stepped footing and foundation wall in masonry construction. 25

26. Foundation Walls • Extend from the first floor to the footing. • May also be basement walls. • Variety of materials may be used: • Cast concrete, concrete block, pressure-treated wood, and stone or brick. • Four basic types of foundation walls: • T-foundation, slab foundation, pier andpost foundation, and wood foundation. 26

27. Foundation Walls • Foundation wall materials. 27

28. Foundation Walls • Foundation types. 28

29. T-Foundations • The T-foundation is the most common type of residential foundation. • Name is derived from the shape. • Footing and foundation wall are usually separate parts. • Footings are usually cast in forms. • Variety of applications of T-foundation. 29

30. T-Foundation Application • 8" foundation wall with insulated slab floor. 30

31. T-Foundation Application • 8" basement wall and footing. 31

32. T-Foundation Application • Insulated slab for perimeter heat. 32

33. T-Foundation Application • 12" concrete block foundation for brick veneer on frame. 33

34. T-Foundation Application • Poured concrete foundation for brick and block wall. 34

35. Footing Forms • Construction boards. 35

36. Footing Forms • Manufactured forms that stay in place and serve as a drain tile. 36 (CertainTeed Corporation)

37. Slab Foundations • A slab foundation is an extension of a slab floor. • Cast when the floor is placed. • Sometimes called thickened edge slab. • Should extend below the frost line. • Reinforcement is recommended. • Advantages: Requires less time, labor, and expense to construct. 37

38. Slab Foundation Application • Foundation for 10" cavity wall with slab floor. 38

39. Slab Foundation Application • Foundation for 10" masonry bonded wall with slab floor. 39

40. Slab Foundation Application • Thickened edge slab foundation for frame wall. 40

41. Slab Foundation Application • 8" bearing wall partition on slab floor. 41

42. Pier and Column Foundations • Piers and columns are similar. • Pier foundations sometimes replaceT-foundations under the house. • Piers often used in a long crawl space. • Columns are used in basements where the span is too long. • The difference between piers and columns is their height. • A column has a footing and post. 42

43. Pier Foundation 43

44. Pier Variations 44

45. Post (Column) Foundation • A pipe or adjustable jack post is frequently used to support a beam. This is a column or post foundation. 45

46. Post (Column) Foundation 46

47. Wood Foundations • Wood foundations are a below-grade, pressure-treated, plywood-sheathed stud wall. • Popular where winter weather stops construction. • Accepted by HUD, FHA, and FmHA. • May be used in basement or crawl space construction. 47

48. Wood Foundation • Typical wood foundation with crawl space. 48

49. Wood Foundation • Typical wood foundation for basement. 49

50. Wood Foundation Construction • Placing the footing plate. 50 (Osmose Wood Products)