FORMS,

FOUNDATIONS, AND

CONCRETE�

OBJECTIVES

• LAY OUT BUILDING LINES AND SET UP BATTER BOARDS.
• DESCRIBE EXCAVATION PROCEDURES.
• DISCUSS THE TYPES OF FOUNDATION SYSTEMS
• EXPLAIN FOOTING REQUIREMENTS AND HOW TO BUILD FOOTING FORMS.
• DESCRIBE THE BUILDING, ERECTING, AND USE OF FORMS FOR POURED FOUNDATION WALLS.

OBJECTIVES

• EXPLAIN HOW SLAB-ON-GRADE CONSTRUCTION IS USED.
• DISCUSS DESIGN FACTORS THAT APPLY TO SIDEWALKS AND DRIVEWAYS.
• EXPLAIN HOW COLD WEATHER AFFECTS CONSTRUCTION.
• ESTIMATE CONCRETE MATERIALS REQUIRED FOR A SPECIFIC AREA.

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LAYING OUT BUILDING LINES

• USE REGISTERED ENGINEER OR LICENSED SURVEYOR TO ESTABLISH BOUNDARIES
• LOCATE BUILDING LINES WITH BUILDER’S LEVEL, TRANSIT, OR THEODOLITE
• CHECK BUILDING LINES CAREFULLY

Dmitry Kalinovsky/Shutterstock.com

EXCAVATION

• OUTLINE IS MARKED WITH STAKES OR LIME
• SHOULD EXTEND AT LEAST 2′ BEYOND BUILDING LINES
• FIND EXCAVATION DEPTH AND FOUNDATION HEIGHT USING CONTROL POINT

Goodheart-Willcox Publisher

SAFETY NOTE: EXCAVATION

• WHENEVER PROJECTS INVOLVE EXCAVATIONS
• DETERMINE LOCATIONS OF UNDERGROUND UTILITY LINES (CALL 811)
• PROVIDE ADEQUATE SHORING IF NEEDED
• PILE EXCAVATED MATERIAL AT SAFE DISTANCE AWAY FROM EXCAVATION
• PUMP WATER OUT OF EXCAVATION
• PROVIDE ADEQUATE LADDERS FOR SAFE EXIT FROM EXCAVATION

SAFETY NOTE: WIRE MESH

• WHEN USING WIRE MESH FOR SLAB REINFORCEMENT, TAKE PRECAUTIONS TO PREVENT ENDS OF UNROLLED MESH FROM SPRINGING UP
• SECURE BOTH ENDS OF MESH OR REVERSE MATERIAL SO IT CURVES DOWNWARD WHEN UNROLLED

REINFORCING FOR CONCRETE

Steel Reinforcing Bars (Re-Rod

20' Lengths Sizes

Number 2 3 4 5 6 7 8 9* 10* 11*

Inches 1/4 3/8 2 /4 5/8 3/4 7/8 1 1 1 1/8 1 1/4

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REINFORCE FOR CONCRETE

Wire Fabric Mesh

5' X 150' Rolls 6" X 6" 10, 8, 6 & 4 Gage

  4" X 4" 13, 10 & 4 Gage

FORMS FOR FOOTINGS

• CONTAIN CONCRETE UNTIL IT IS CURED
• CONSTRUCTED OF 2″ LUMBER
• SUPPORT STAKES PLACED AT 4′ INTERVALS
• TIES NAILED ACROSS TOP OF FORM BOARDS AT INTERVALS
• ADDITIONAL PLASTIC FOOTING METHOD
• STEPPED FOOTINGS REQUIRE ADDITIONAL FORMWORK

PROCEDURE: CONSTRUCTING FOOTING FORMS

• DRIVE STAKES AND ESTABLISH POINTS AT FOUNDATION WALL CORNERS
• SET UP LASER OR BUILDER’S LEVEL AT CENTRAL POINT
• DRIVE GRADE STAKES LEVEL WITH TOP OF FOOTING
• CONNECT CORNER STAKES WITH LINES TIED TO NAIL ON TOP OF STAKES
• CONSTRUCT OUTSIDE FORM FOR FOOTING
• LEVEL INSIDE OF FORM WITH STEEL TAPE AND LEVEL
• BRACE FORMS AS NEEDED
• USE LEVEL TO RECHECK HEIGHT AT SEVERAL POINTS

COLUMN FOOTINGS

• PADS OF CONCRETE DESIGNED TO SUPPORT COLUMNS
• DISTRIBUTES LOAD TO THE GROUND
• SET AFTER FOOTING FORMS
• SOME HAND DIGGING AND LEVELING IS REQUIRED
• PLACE REBAR IF REQUIRED, SUPPORT OFF THE GROUND

ERECTING WALL FORMS

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• MUST BE
• TIGHT, SMOOTH, DEFECT FREE, AND PROPERLY ALIGNED
• STRONG AND WELL-BRACED TO RESIST SIDE PRESSURE CREATED BY CONCRETE

FORM HARDWARE

• WIRE TIES AND WOODEN SPREADERS REPLACED WITH MANUFACTURED DEVICES
• FORM OR SNAP TIE HOLDS SIDES OF FORM TOGETHER AT RIGHT DISTANCE
• WALERS SECURE CORNERS
• STRONGBACKS ARE NAILED TO WALERS

PANEL FORMS

• PREFABRICATED PANELS USED FOR MOST POURED CONCRETE WALL FORMS
• MADE FROM PLYWOOD, STEEL, OR ALUMINUM
• DESIGNED TO BE USED MANY TIMES
• WALERS USED FOR STIFFENING AND BRACES TO KEEP PLUMB
• RELEASE COATING PREVENTS CONCRETE FROM STICKING TO SURFACE

PILASTERS AND COLUMN FORMS

• PILASTERS
• THICKENED SECTIONS OF CONCRETE OR MASONRY WALLS
• STRENGTHEN WALLS OR SUPPORT BEAMS
• PREFABRICATED FORMS SAVE TIME FOR STANDARD SQUARE OR RECTANGULAR COLUMNS

CONCRETE

• MADE BY MIXING MEASURED AMOUNTS OF
• CEMENT
• FINE AGGREGATE (SAND)
• COARSE AGGREGATE (GRAVEL OR CRUSHED STONE)
• WATER
• HYDRATION CAUSES HARDENING OF MIXTURE

CURING METHODS

• FLOODING
• KEEP SPRINKLER RUNNING
• OTHER METHODS
• COVERING WITH BURLAP OR OTHER MATERIAL
• COVERING WITH PLASTIC AND SEALING LAPS
• USING LIQUID-MEMBRANE COMPOUND TO SEAL IN MOISTURE

SLUMP TESTING

• ASSESSES CONSISTENCY, STIFFNESS, AND WORKABILITY OF FRESH CONCRETE
• MORE WATER MEANS MORE SLUMP
• CAN BE DONE AT JOBSITE OR AT READY-MIX PLANT

PROCEDURE: MAKING A SLUMP TEST

• SECURE SLUMP CONE, WET IT, AND PLACE UPRIGHT
• FILL CONE WITH CONCRETE, STRIKE OFF THE TOP, THEN REMOVE CONE
• TURN CONE, PLACE NEXT TO CONCRETE, AND LAY TAMPING ROD ACROSS THE TOP
• USE RULER TO MEASURE SLUMP

PLACING CONCRETE

• USUALLY CAN BE PLACED INTO FORMS FROM TRUCK
• WHEELBARROW OR PUMP IS USED FOR OTHER AREAS
• BAFFLES USED ON SLOPES PREVENT COLLECTING OF AGGREGATE AT BOTTOM

SAFETY NOTE: CONCRETE

• CHEMICAL REACTION IN CURING CONCRETE GENERATES HEAT
• CAN CAUSE CHEMICAL BURNS ON BARE SKIN
• WEAR SAFETY GLASSES, RUBBER BOOTS, AND GLOVES WHEN WORKING WITH CONCRETE

SIDEWALKS, STEPS, AND DRIVES

• MAIN WALKS LEADING TO FRONT ENTRANCES SHOULD BE AT LEAST 4′ WIDE
• WHEN JOINING TWO LEVELS WITH STEPS, POUR TOP LEVEL FIRST
• DRIVEWAYS SHOULD BE 5″ OR 6″ THICK WITH REINFORCING MESH

FINISHING WALKS AND DRIVES

• SPREAD CONCRETE ROUGHLY BETWEEN FORMS
• AFTER SPREADING, IMMEDIATELY SCREED CONCRETE
• AFTER SCREEDING, MOVE FLOAT OVER SURFACE
• START SURFACE FINISHING AFTER CONCRETE IS STIFF

FORMING CONTROL JOINTS

• CONTROL JOINTS CAN BE FORMED WITH
• GROOVER AND STRAIGHTEDGE
• POWER SAW WITH MASONRY BLADE
• START SAWING 18–24 HOURS AFTER CONCRETE IS PLACED
• JOINTS SHOULD EXTEND TO DEPTH OF AT LEAST ONE-FIFTH THICKNESS OF CONCRETE
• PROTECT CONCRETE AGAINST LOSING MOISTURE TOO QUICKLY DURING HARDENING

CONCRETE TOOLS

• HAND TROWELS
• BULL FLOATS
• MAGNESIUM FLOATS
• WOOD FLOATS
• SPONGE FLOATS
• EDGER
• SCREEDS
• WALKING TROWELS
• FRESNO TROWELS
• HANDLES
• FINISHING BROOMS
• RAKES

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COLD WEATHER CONSTRUCTION

• MAY REQUIRE CHANGES IN HANDLING MATERIALS
• HEAT MATERIALS
• COVER FRESHLY PLACED CONCRETE OR MASONRY
• ERECT ENCLOSURE AND KEEP AREA HEATED
• AVOID PLACING CONCRETE ON FROZEN GROUND
• MATERIALS USED IN MORTAR SHOULD BE AT PROPER TEMPERATURES
• TEMPORARY SHELTERS OR COVERINGS CAN BE USED

ESTIMATING MATERIALS

• CONCRETE IS MEASURED BY CUBIC YARD
• ALLOW EXTRA CONCRETE FOR WASTE OR SLIGHT VARIATION IN FORM
• USE FORMULAS TO CALCULATE VOLUME