Competency 204 00 Draw Foundation Plans Objective 204

Competency: 204. 00 Draw Foundation Plans Objective: 204. 03 Explain footing and foundation wall construction.

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

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

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

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

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

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

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

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

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

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

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

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