1

1

J. Edward Sauter, NCARBExecutive Director, Concrete Foundations Association

What to do WhenYour Foundation

Contractor isGone?

2

Resources ACI 332-04 (American Concrete Inst) CFA Standard (Concrete Fndn Assoc) IRC (International Residential Code) Residential Foundations (NAHB)

3

WhyBuild aBasement?

Frost Protection

Security and Safety

More Living Space

2

4

Foundation System Soil Concrete Footing Vertical Wall System

Wall (Reinforced or Plain) Top Restraint Bottom Restraint

Backfill Water Protection

Waterproofing/Dampproofing Drainage System Site Drainage

5

What is Concrete?

Portland Cement Water Large Aggregate Small Aggregate

6

Characteristics of Concrete

It Gets Hard and It Cracks Weight +/- 150 # Cubic Foot Compressive Strength = 2500 - 5000 psi Tensile Strength (MOR) = 300 to 500 psi Measured by the Cubic Yard

(1 CY = 5 lf of 8”x 8’-0”wall)

3

7

Curing Concrete

Needs Three Conditions to CureMoistureTimeTemperature

8

Impact of Adding Water

Lower strength (200 psi/Gallon of Water) Higher permeability Decreased resistance to weathering Poorer bond between concrete and reinforcement Increased drying shrinkage and cracking Greater volume change from wetting and drying

Harming Concrete

9

Spread Footings

Side FormsLateral Restraint

4

10

Foundation Wall Simply Supported

Top and Bottom Transfer of Vertical

Load to Footing Vertical Flexural

Member (ResistLateral Loads)

Extend FoundationBelow Frost Depth

Enclose Lower LevelSpace

11

Reinforcement Plain Structural

Concrete WallTemperature & Shrinkage(3 horizontal in 8’)(4 horizontals above 8’)

Reinforced ConcreteWallTemperature & Shrinkageplus StructuralReinforcement(vertical, inside face of wall)

12

ACI Empirical Wall Table

5

13

Bottom Restraint Dowel Rod Keyway Basement Slab

14

Top Restraint Anchor Bolt Plate Joists Deck

15

Anchor Strap Installation

6

16

RCFs(Removable Concrete Forms)

Designed for Production

The entirefoundation istypically installedon a three-dayconstructioncycle!

17

Foundation Cycle - Day 1

Footings are Cast

18

Foundation Cycle - Day 2

Wall Forming

The sturdy formsare set in place oneside of the wall at atime.

7

19

Foundation Cycle - Day 2

The Wall is CastA local ready-mixtruck brings qualitydesigned concrete tothe job site forplacement.

20

Foundation Cycle - Day 3

Forms are Removed

Preparing the wall for….

21

The Drainage (Sub) System

Drain Tile Membrane Backfill Material Finish Grading

8

22

DampproofingWill not span discontinuities (cracks)

23

Waterproofing

24

BackfillingConcrete Reaches Sufficient Strength (7 days) Top and Bottom Bracing is in Place Suitable Backfill Material

9

25

Braced Foundation Wall

26

No Top Restraint?

Backfill at Corners Only Backfill to 4’ Length (IRC) Short Wall Segments (8’-12’) Counterforts Temporary Bracing

27

Finish Grading (IRC) 6” in First 10 (after settlement) 6” Below Top

of Concrete

4”@Masonry Veneer

10

28

Cracks

Temperature Change Shrinkage Water Pressure Vehiclular Loads Pour Lines Settlement

Why Does Concrete Crack?

29

Cracks

Lower Water Content Steel Reinforcement Construction Joints

Methods of Minimizing Cracks

Leaking Displacement Bowing of Wall Width > 1/8”

When is a Crack a Concern?

30

Cracks

Surface Drainage Drainage System Waterproofing Epoxy Injection Structural Modifications

Crack Impact Mitigation