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TABLE F FOUNDATION EMBEDMENT MINIMUM DEPTHS (A) <br /> SUB-GRADE PERIMETER ALL FOUNDATIONS <br /> BENEATH FOUDATIONS IN IN UNHEATED ALL FOUNDATIONS <br /> FOUNDATIONS BUILDINGS AND IN HEATED AREAS. <br /> AND STRUCTURES HEATED BUILDINGS STRUCTURES <br /> Well-drained <br /> granular material 42" 60" No protection required <br /> Poorly-drained <br /> granular.material 48 72" No protection required <br /> Poorly-drained <br /> clayey material 48" 72" No protection required <br /> Note (A): Protection against frost heaving and adfreezing must be provided. <br /> METHOD ONE Prevent adfreezing by separating the foundation surface from frost-susceptible <br /> soil. Place non-frost-susceptible materialagainst the surface. Granular material (sand and gravel) <br /> that is clean (up to 5 percent fines passing #200 sieve) is considered non-frost susceptible <br /> — material. Silt and silty soil is highly frost-susceptible. Granular material must be free-draining and <br /> permanently well-drained into subsurface drain lines to prevent water from accumulating and <br /> freezing in foundation backfill. Poor-draining backfill can potentially freeze into a solid mass of ice <br /> mixed with backfill. This can cause adfreezing and heaving of foundations. Drain lines must be <br /> installed according to recommendations in the WATERPROOFING section of this report. <br /> METHOD TWO Anchor foundation walls to spread footings for heave resistance. The <br /> maximum anticipated frost line depth must be above the footing top to provide resistance. A zone <br /> -- of unfrozen soil must remain between the frost line and top of footing. Soil in this zone must be <br /> allowed to compress by downward movement of overlying frozen soil. This compresses the <br /> adjoining foundation, which counteracts foundation extension by adfreezing in the overlying frost <br /> penetrated zone. Foundation backfill must be compacted to maximum dry soil density to minimize <br /> its compressibility and its heaving potential. This method must be carefully reviewed and approved <br /> by a structural engineer before implementation. <br /> METHOD THREE Place.polystyrene foam insulation boards horizontally over frost susceptible <br /> foundation backfill material. Bury boards deep enough.to prevent crushing by wheel loads. Burial <br /> material must be separated from foundation surfaces to prevent adfreezing. Board thickness must <br /> be designed using degree/ day/Btu methods and it should be'nearly 2 or more inches. Boards <br /> must extend horizontally outward from foundations a distance greater than the frost penetration. <br /> _ BACKFILL CAP AND WATER RUNOFF Foundation backfill must be capped with impermeable <br /> cohesive soil (CL) to minimize water infiltration into backfill. Surface water run-off must be directed <br /> away from buildings and structures. Landscaped surfaces within 10 feet of buildings and <br /> structures must have at least 10 percent drainage grades, while impervious surfaces within this 10 <br /> Allied Project 04049 9 July 27, 2004 <br />