Competency: 204.00 Draw Foundation Plans Objective: 204.03 Explain footing and foundation wall construction.

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

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

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

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

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

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

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

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

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

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

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

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