Roof Terms Span –Distance across the building

Roof Terms Run –1/2 the distance across the building (1/2 span distance)

Roof Terms Rise –The distance the roof rises (distance from the square of house to ridge)

Calculating Roof Surface Calculate horizontal area Determine slope factor (ratio between run and hypotenuse of the roof pitch Multiply slope factor times horizontal area feet 35 feet 12 5

FOUNDATIONS 5

Foundations Luke 6: “He is like a man building a house, who dug deep and laid the foundation on the rock. And when the flood arose, the stream beat vehemently against that house, and could not shake it, for it was founded on the rock.” 49.“But he who heard and did nothing is like a man who built a house on the earth without a foundation, against which the stream beat vehemently; and immediately it fell. And the ruin of that house was great.”

FOUNDATION FAILURES STAND OUT 7

3 BASIC REQUIREMENTS A foundation must: Not be susceptible to collapse, Not allow settlement to occur which results in damage or failure of the superstructure to function as it should, and Be feasible and buildable without affecting surroundings. 8

Foundation Design Factors Loads & Pressures Soil Climatological and water control (Frost, drainage, etc.)

Loads & Pressures Foundation walls must be strong enough to resist applied loads

FOUNDATION LOADS Dead loads Live loads Wind loads Other horizontal loads (?) Buoyant loads Earthquake (seismic) loads 11

SOIL TYPES ROCK SOIL BOULDERS COBBLES GRAVEL SAND SILT CLAY 12

Soil Types Bearing Capacity Rock4000 psi or 20% (crushing value) Gravel2000 Sand –Course 1500 –Fine1000 Clay –Hard3000 –Sandy2000 –Soft1000 Adobe 1000 Silt 500 Bearing capacity of the soil depends on soil composition and moisture content

Climate Considerations Moisture/Water Content –permeability of soil--water absorbed into soil causes expansion, thus causing the foundation to heave Surface and ground water must have proper drainage –Codes require finish grade to slope away from the foundation at minimum slopes: planted--1/2”/12” 6 foot away from building paved areas--1% slope

Climate Considerations Freezing –Water expands as it freezes –Expansion and shrinking of the soil causes heaving in the foundation –General depth requirement/guideline 12” below average frost depth –Design for sizing footing is determined by the calculations done by the architect or engineer considering loads and soil conditions or using code, depth may follow the rule given above

Climate Conditions Frost Depth Chart

FOUNDATION SELECTION PRIMARY SUBSURFACE AND GROUND WATER STRUCTURAL REQUIREMENTS SECONDARY CONSTRUCTION METHODS ENVIRONMENT CODES / REGULATIONS IMPACTON NEARBY FACILITIES TIME AVAILABLE FOR CONSTRUCTION CONSTRUCTION RISKS 17

TYPES OF FOUNDATIONS DEEP CAISSONS PILES SHALLOW COLUMN FOOTINGS WALL FOOTINGS SLAB ON GRADE MATS FLOATING 18

Pilings Cast-in-Place concrete piling shapes Steel Piling Detail Drawing

Caisson Rebar Cage 20

COLUMN / WALL FOOTINGS 21

Pier Foundations Pier foundation resemble pedestal foundations Pier Foundation Drawing Representations

Grade Beams Replaces footings in unstable soil Grade beam becomes an actual beam support by pilings or large pier footings

Mat Foundation 24

Stepped Foundation Most Codes give limits: Height of step = 24” maximum Run of step = 32” minimum

Slab or Monolithic Foundations On-Grade Slabs-- called Monolithic if foundation and slab are poured together One Placement Two Placements

Foundation Reinforcement Concrete & Masonry Resists Compressive Forces Concrete & Masonry lousy in resisting Tensile Forces

Foundation Wall Reinforcement Reinforcing Bar (Rebar) is placed in the foundation wall to resist possible lateral and bending forces.

Footing Reinforcement When the footing is placed near conditions of expansive soil, the bottom of the footing will bend, placing the footing in tension. Steel reinforcement is placed in the bottom of the footing to resist the forces of tension in concrete. The distance from the bottom of the footing: –Cover varies (1 ½” to 3” coverage) depends on size of reinforcement and exposure conditions. (formed, not formed, in contact with soil or not, environment, etc.)

Slab Reinforcement WWF is used to help the slab resist cracking Also placed near the surface in grid patterns to help resist tension in bending Steel rebar can also be used to prevent bending of the slab due to beam action in the slab

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SETTLEMENT UNIFORM SETTLEMENT DIFFERENTIAL SETTLEMENT 32