1. Competency: 204.00 Draw Foundation Plans
Objective:
Explain footing and foundation wall construction.

2. Footings Wider than foundation wall Purpose
Spread entire load of structure over wider area
Prevents uneven settlement

3. Determine Footing Sizes
Live loads include movable items
People
Wind
Snow
Furniture
Dead loads include all of the structure construction materials
Different soil types
Support varying loads

4. Footings Generally made of poured concrete Trench shapes footing
Forms constructed for unstable soils
Concrete withstands heavy loads
Steel rebar adds support

5. Footing Design & Construction
Proper design & construction of utmost importance
Larger footings
Aid in prevention of uneven settlement
Different loading conditions
May cause uneven settlement

6. Footing Design & Construction
Effects of uneven settlement
Doors & windows stick
Cracks in finish materials
Leaks in plumbing
Structural element failure

7. Frost line Depth to which the ground will freeze
Depth varies with geographic location
Local codes specify minimum footing depth
Footing placed below frost line
Ground freezes & thaws
Expands and contracts
Footing above frost line will be pushed upward
Causes cracks in foundation

8. Foundation Wall Extends from footing upward to first floor
Commonly used materials
Poured concrete
Concrete block
Brick
Tile

9. Foundation Wall Poured Concrete
Composition
Cement
Water
Stone or other aggregrate
Use key to tie walls to poured footing

10. Foundation Walls Concrete Block
Most common CMU
Nominal size: 8”high x 8”thick x 16” long
Actual size: 7-5/8” x 7-5/8” x 15-3/8” with 3/8” mortar joint
Thickness: 4”, 8”, 10”, 12”
Styles
2 & 3 core stretchers
Solids
Lintels
Corner
Pilaster
Jamb blocks

11. Foundation Walls Thickness varies
Construction factors
Local codes
Soil conditions
Shape is designed to handle horizontal earth movement
Lateral earth shifting causes damage

12. Foundation Walls Require damp proofing
Heavy coats of tar or cement based paint
Thin coats of parging
Drain tile
Perforated pipe surrounds structure
Washed gravel holds back soil; allows water to enter pipe
Water is directed away from foundation

13. Foundation Walls Polyethylene sheeting
Thickness measured in millimeters (mils)
6 mil most common